chore: Cut release 0.13.0

## Summary

- Nav file in EPUB 3 file is a HTML file with relative hrefs
- If this file exists anywhere but in the same location as the
content.opf file, navigating in the book will fail
- Bump the book cache version to rebuild potentially broken books

## Additional Context

- Fixes https://github.com/daveallie/crosspoint-reader/issues/264

---

### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code?

- [ ] Yes
- [ ] Partially
- [x] No

.github/PULL_REQUEST_TEMPLATE.md

@@ -1,9 +1,18 @@
 ## Summary
 
-* **What is the goal of this PR?** (e.g., Fixes a bug in the user authentication module, Implements the new feature for 
+* **What is the goal of this PR?** (e.g., Implements the new feature for file uploading.)
-  file uploading.)
 * **What changes are included?**
 
 ## Additional Context
 
-* Add any other information that might be helpful for the reviewer (e.g., performance implications, potential risks, specific areas to focus on).
+* Add any other information that might be helpful for the reviewer (e.g., performance implications, potential risks, 
+  specific areas to focus on).
+
+---
+
+### AI Usage
+
+While CrossPoint doesn't have restrictions on AI tools in contributing, please be transparent about their usage as it 
+helps set the right context for reviewers.
+
+Did you use AI tools to help write this code? _**< YES | PARTIALLY | NO >**_

.github/workflows/ci.yml

@@ -7,11 +7,11 @@ name: CI
 jobs:
   build:
     runs-on: ubuntu-latest
-
     steps:
       - uses: actions/checkout@v6
         with:
           submodules: recursive
+
       - uses: actions/setup-python@v6
         with:
           python-version: '3.14'

.github/workflows/release.yml

@@ -7,17 +7,18 @@ on:
 jobs:
   build-release:
     runs-on: ubuntu-latest
-
     steps:
       - uses: actions/checkout@v6
         with:
           submodules: recursive
+
       - uses: actions/cache@v5
         with:
           path: |
             ~/.cache/pip
             ~/.platformio/.cache
           key: ${{ runner.os }}-pio
+
       - uses: actions/setup-python@v6
         with:
           python-version: '3.14'

README.md

@@ -25,7 +25,7 @@ This project is **not affiliated with Xteink**; it's built as a community projec
 
 ## Features & Usage
 
-- [x] EPUB parsing and rendering
+- [x] EPUB parsing and rendering (EPUB 2 and EPUB 3)
 - [ ] Image support within EPUB
 - [x] Saved reading position
 - [x] File explorer with file picker
@@ -33,11 +33,13 @@ This project is **not affiliated with Xteink**; it's built as a community projec
   - [x] Support nested folders
   - [ ] EPUB picker with cover art
 - [x] Custom sleep screen
-  - [ ] Cover sleep screen
+  - [x] Cover sleep screen
 - [x] Wifi book upload
-- [ ] Wifi OTA updates
+- [x] Wifi OTA updates
-- [ ] Configurable font, layout, and display options
+- [x] Configurable font, layout, and display options
-- [ ] Screen rotation
+  - [ ] User provided fonts
+  - [ ] Full UTF support
+- [x] Screen rotation
 
 See [the user guide](./USER_GUIDE.md) for instructions on operating CrossPoint.
 

USER_GUIDE.md

@@ -1,17 +1,18 @@
 # CrossPoint User Guide
 
-Welcome to the **CrossPoint** firmware. This guide outlines the hardware controls, navigation, and reading features of 
+Welcome to the **CrossPoint** firmware. This guide outlines the hardware controls, navigation, and reading features of the device.
-the device.
 
 ## 1. Hardware Overview
 
-The device utilises the standard buttons on the Xtink X4 in the same layout:
+The device utilises the standard buttons on the Xtink X4 (in the same layout as the manufacturer firmware, by default):
 
 ### Button Layout
 | Location        | Buttons                                              |
-|-----------------|--------------------------------------------|
+| --------------- | ---------------------------------------------------- |
 | **Bottom Edge** | **Back**, **Confirm**, **Left**, **Right**           |
-| **Right Side**  | **Power**, **Volume Up**, **Volume Down**  |
+| **Right Side**  | **Power**, **Volume Up**, **Volume Down**, **Reset** |
+
+Button layout can be customized in **[Settings](#35-settings)**.
 
 ---
 
@@ -19,14 +20,16 @@ The device utilises the standard buttons on the Xtink X4 in the same layout:
 
 ### Power On / Off
 
-To turn the device on or off, **press and hold the Power button for half a second**. In **Settings** you can configure
+To turn the device on or off, **press and hold the Power button for half a second**. In **[Settings](#35-settings)** you can configure the power button to trigger on a short press instead of a long one.
-the power button to trigger on a short press instead of a long one.
+
+To reboot the device (for example if it's frozen, or after a firmware update), press and release the Reset button, and then hold the Power button for a few seconds.
 
 ### First Launch
 
-Upon turning the device on for the first time, you will be placed on the **Home** screen.
+Upon turning the device on for the first time, you will be placed on the **[Home](#31-home-screen)** screen.
 
-> **Note:** On subsequent restarts, the firmware will automatically reopen the last book you were reading.
+> [!NOTE]
+> On subsequent restarts, the firmware will automatically reopen the last book you were reading.
 
 ---
 
@@ -34,49 +37,70 @@ Upon turning the device on for the first time, you will be placed on the **Home*
 
 ### 3.1 Home Screen
 
-The Home Screen is the main entry point to the firmware. From here you can navigate to the **Book Selection** screen,
+The Home Screen is the main entry point to the firmware. From here you can navigate to **[Reading Mode](#4-reading-mode)** with the most recently read book, **[Book Selection](#32-book-selection)**, **[Settings](#35-settings)**, or the **[File Upload](#34-file-upload-screen)** screen.
-**Settings** screen, or **File Upload** screen.
 
-### 3.2 Book Selection (Read)
+### 3.2 Book Selection
 
 The Book Selection acts as a folder and file browser.
 
-* **Navigate List:** Use **Left** (or **Volume Up**), or **Right** (or **Volume Down**) to move the selection cursor up 
+* **Navigate List:** Use **Left** (or **Volume Up**), or **Right** (or **Volume Down**) to move the selection cursor up and down through folders and books. You can also long-press these buttons to scroll a full page up or down.
-  and down through folders and books.
 * **Open Selection:** Press **Confirm** to open a folder or read a selected book.
 
-### 3.3 Reading Screen
+### 3.3 Reading Mode
 
-See [4. Reading Mode](#4-reading-mode) below for more information.
+See [Reading Mode](#4-reading-mode) below for more information.
 
 ### 3.4 File Upload Screen
 
-The File Upload screen allows you to upload new e-books to the device. When you enter the screen you'll be prompted with
+The File Upload screen allows you to upload new e-books to the device. When you enter the screen, you'll be prompted with a WiFi selection dialog and then your X4 will start hosting a web server.
-a WiFi selection dialog and then your X4 will start hosting a web server.
 
 See the [webserver docs](./docs/webserver.md) for more information on how to connect to the web server and upload files.
 
+> [!TIP]
+> Advanced users can also manage files programmatically or via the command line using `curl`. See the [webserver docs](./docs/webserver.md) for details.
+
 ### 3.5 Settings
 
 The Settings screen allows you to configure the device's behavior. There are a few settings you can adjust:
-- **Sleep Screen**: Which sleep screen to display when the device sleeps, options are:
+- **Sleep Screen**: Which sleep screen to display when the device sleeps:
   - "Dark" (default) - The default dark sleep screen
   - "Light" - The same default sleep screen, on a white background
-  - "Custom" - Custom images from the SD card, see [3.6 Sleep Screen](#36-sleep-screen) below for more information
+  - "Custom" - Custom images from the SD card, see [Sleep Screen](#36-sleep-screen) below for more information
   - "Cover" - The book cover image (Note: this is experimental and may not work as expected)
-- **Extra Paragraph Spacing**: If enabled, vertical space will be added between paragraphs in the book, if disabled,
+  - "Blank" - A blank screen
-  paragraphs will not have vertical space between them, but will have first word indentation.
+- **Status Bar**: Configure the status bar displayed while reading:
+  - "None" - No status bar
+  - "No Progress" - Show status bar without reading progress
+  - "Full" - Show status bar with reading progress
+- **Extra Paragraph Spacing**: If enabled, vertical space will be added between paragraphs in the book. If disabled, paragraphs will not have vertical space between them, but will have first-line indentation.
 - **Short Power Button Click**: Whether to trigger the power button on a short press or a long press.
-- **Front Button Layout**: Swap the order of the bottom edge buttons from Back/Confirm/Left/Right to Left/Right/Back/Confirm.
+- **Reading Orientation**: Set the screen orientation for reading:
+  - "Portrait" (default) - Standard portrait orientation
+  - "Landscape CW" - Landscape, rotated clockwise
+  - "Inverted" - Portrait, upside down
+  - "Landscape CCW" - Landscape, rotated counter-clockwise
+- **Front Button Layout**: Configure the order of the bottom edge buttons:
+  - Back, Confirm, Left, Right (default)
+  - Left, Right, Back, Confirm
+  - Left, Back, Confirm, Right
+- **Side Button Layout**: Swap the order of the up and down volume buttons from Previous/Next to Next/Previous. This change is only in effect when reading.
+- **Reader Font Family**: Choose the font used for reading:
+  - "Bookerly" (default) - Amazon's reading font
+  - "Noto Sans" - Google's sans-serif font
+  - "Open Dyslexic" - Font designed for readers with dyslexia
+- **Reader Font Size**: Adjust the text size for reading; options are "Small", "Medium", "Large", or "X Large".
+- **Reader Line Spacing**: Adjust the spacing between lines; options are "Tight", "Normal", or "Wide".
+- **Reader Paragraph Alignment**: Set the alignment of paragraphs; options are "Justified" (default), "Left", "Center", or "Right".
+- **Time to Sleep**: Set the duration of inactivity before the device automatically goes to sleep.
+- **Refresh Frequency**: Set how often the screen does a full refresh while reading to reduce ghosting.
+- **Check for updates**: Check for firmware updates over WiFi.
 
 ### 3.6 Sleep Screen
 
 You can customize the sleep screen by placing custom images in specific locations on the SD card:
 
 - **Single Image:** Place a file named `sleep.bmp` in the root directory.
-- **Multiple Images:** Create a `sleep` directory in the root of the SD card and place any number of `.bmp` images
+- **Multiple Images:** Create a `sleep` directory in the root of the SD card and place any number of `.bmp` images inside. If images are found in this directory, they will take priority over the `sleep.bmp` file, and one will be randomly selected each time the device sleeps.
-  inside. If images are found in this directory, they will take priority over the `sleep.png` file, and one will be
-  randomly selected each time the device sleeps.
 
 > [!NOTE]
 > You'll need to set the **Sleep Screen** setting to **Custom** in order to use these images.
@@ -94,17 +118,20 @@ Once you have opened a book, the button layout changes to facilitate reading.
 
 ### Page Turning
 | Action            | Buttons                              |
-|-------------------|--------------------------------------|
+| ----------------- | ------------------------------------ |
 | **Previous Page** | Press **Left** _or_ **Volume Up**    |
 | **Next Page**     | Press **Right** _or_ **Volume Down** |
 
+The role of the volume (side) buttons can be swapped in **[Settings](#35-settings)**.
+
 ### Chapter Navigation
 * **Next Chapter:** Press and **hold** the **Right** (or **Volume Down**) button briefly, then release.
 * **Previous Chapter:** Press and **hold** the **Left** (or **Volume Up**) button briefly, then release.
 
 ### System Navigation
-* **Return to Home:** Press **Back** to close the book and return to the Book Selection screen.
+* **Return to Book Selection:** Press **Back** to close the book and return to the **[Book Selection](#32-book-selection)** screen.
-* **Chapter Menu:** Press **Confirm** to open the Table of Contents/Chapter Selection screen.
+* **Return to Home:** Press and **hold** the **Back** button to close the book and return to the **[Home](#31-home-screen)** screen.
+* **Chapter Menu:** Press **Confirm** to open the **[Table of Contents/Chapter Selection](#5-chapter-selection-screen)**.
 
 ---
 
@@ -120,9 +147,6 @@ Accessible by pressing **Confirm** while inside a book.
 
 ## 6. Current Limitations & Roadmap
 
-Please note that this firmware is currently in active development. The following features are **not yet supported** but
+Please note that this firmware is currently in active development. The following features are **not yet supported** but are planned for future updates:
-are planned for future updates:
 
 * **Images:** Embedded images in e-books will not render.
-* **Text Formatting:** There are currently no settings to adjust font type, size, line spacing, or margins.
-* **Rotation**: Different rotation options are not supported.

docs/file-formats.md

@@ -2,8 +2,220 @@
 
 ## `book.bin`
 
-![](./images/file-formats/book-bin.png)
+### Version 3
+
+ImHex Pattern:
+
+```c++
+import std.mem;
+import std.string;
+import std.core;
+
+// === Configuration ===
+#define EXPECTED_VERSION 3
+#define MAX_STRING_LENGTH 65535
+
+// === String Structure ===
+
+struct String {
+    u32 length [[hidden, comment("String byte length")]];
+    if (length > MAX_STRING_LENGTH) {
+        std::warning(std::format("Unusually large string length: {} bytes", length));
+    }
+    char data[length] [[comment("UTF-8 string data")]];
+} [[sealed, format("format_string"), comment("Length-prefixed UTF-8 string")]];
+
+fn format_string(String s) {
+    return s.data;
+};
+
+// === Metadata Structure ===
+
+struct Metadata {
+    String title [[comment("Book title")]];
+    String author [[comment("Book author")]];
+    String coverItemHref [[comment("Path to cover image")]];
+    String textReferenceHref [[comment("Path to guided first text reference")]];
+} [[comment("Book metadata information")]];
+
+// === Spine Entry Structure ===
+
+struct SpineEntry {
+    String href [[comment("Resource path")]];
+    u32 cumulativeSize [[comment("Cumulative size in bytes"), color("FF6B6B")]];
+    s16 tocIndex [[comment("Index into TOC (-1 if none)"), color("4ECDC4")]];
+} [[comment("Spine entry defining reading order")]];
+
+// === TOC Entry Structure ===
+
+struct TocEntry {
+    String title [[comment("Chapter/section title")]];
+    String href [[comment("Resource path")]];
+    String anchor [[comment("Fragment identifier")]];
+    u8 level [[comment("Nesting level (0-255)"), color("95E1D3")]];
+    s16 spineIndex [[comment("Index into spine (-1 if none)"), color("F38181")]];
+} [[comment("Table of contents entry")]];
+
+// === Book Bin Structure ===
+
+struct BookBin {
+    // Header
+    u8 version [[comment("Format version"), color("FFD93D")]];
+    
+    // Version validation
+    if (version != EXPECTED_VERSION) {
+        std::error(std::format("Unsupported version: {} (expected {})", version, EXPECTED_VERSION));
+    }
+    
+    u32 lutOffset [[comment("Offset to lookup tables"), color("6BCB77")]];
+    u16 spineCount [[comment("Number of spine entries"), color("4D96FF")]];
+    u16 tocCount [[comment("Number of TOC entries"), color("FF6B9D")]];
+    
+    // Metadata section
+    Metadata metadata [[comment("Book metadata")]];
+    
+    // Validate LUT offset alignment
+    u32 currentOffset = $;
+    if (currentOffset != lutOffset) {
+        std::warning(std::format("LUT offset mismatch: expected 0x{:X}, got 0x{:X}", lutOffset, currentOffset));
+    }
+    
+    // Lookup Tables
+    u32 spineLut[spineCount] [[comment("Spine entry offsets"), color("4D96FF")]];
+    u32 tocLut[tocCount] [[comment("TOC entry offsets"), color("FF6B9D")]];
+    
+    // Data Entries
+    SpineEntry spines[spineCount] [[comment("Spine entries (reading order)")]];
+    TocEntry toc[tocCount] [[comment("Table of contents entries")]];
+};
+
+// === File Parsing ===
+
+BookBin book @ 0x00;
+
+// Validate we've consumed the entire file
+u32 fileSize = std::mem::size();
+u32 parsedSize = $;
+
+if (parsedSize != fileSize) {
+    std::warning(std::format("Unparsed data detected: {} bytes remaining at offset 0x{:X}", fileSize - parsedSize, parsedSize));
+}
+```
 
 ## `section.bin`
 
-![](./images/file-formats/section-bin.png)
+### Version 8
+
+ImHex Pattern:
+
+```c++
+import std.mem;
+import std.string;
+import std.core;
+
+// === Configuration ===
+#define EXPECTED_VERSION 8
+#define MAX_STRING_LENGTH 65535
+
+// === String Structure ===
+
+struct String {
+    u32 length [[hidden, comment("String byte length")]];
+    if (length > MAX_STRING_LENGTH) {
+        std::warning(std::format("Unusually large string length: {} bytes", length));
+    }
+    char data[length] [[comment("UTF-8 string data")]];
+} [[sealed, format("format_string"), comment("Length-prefixed UTF-8 string")]];
+
+fn format_string(String s) {
+    return s.data;
+};
+
+// === Page Structure ===
+
+enum StorageType : u8 {
+    PageLine = 1
+};
+
+enum WordStyle : u8 {
+    REGULAR = 0,
+    BOLD = 1,
+    ITALIC = 2,
+    BOLD_ITALIC = 3
+};
+
+enum BlockStyle : u8 {
+    JUSTIFIED = 0,
+    LEFT_ALIGN = 1,
+    CENTER_ALIGN = 2,
+    RIGHT_ALIGN = 3,
+};
+
+struct PageLine {
+  s16 xPos;
+  s16 yPos;
+  u16 wordCount;
+  String words[wordCount];
+  u16 wordXPos[wordCount];
+  WordStyle wordStyle[wordCount];
+  BlockStyle blockStyle;
+};
+
+struct PageElement {
+    u8 pageElementType;
+    if (pageElementType == 1) {
+        PageLine pageLine [[inline]];
+    } else {
+        std::error(std::format("Unknown page element type: {}", pageElementType));
+    }
+};
+
+struct Page {
+    u16 elementCount;
+    PageElement elements[elementCount] [[inline]];
+};
+
+// === Section Bin Structure ===
+
+struct SectionBin {
+    // Header
+    u8 version [[comment("Format version"), color("FFD93D")]];
+    
+    // Version validation
+    if (version != EXPECTED_VERSION) {
+        std::error(std::format("Unsupported version: {} (expected {})", version, EXPECTED_VERSION));
+    }
+    
+    // Cache busting parameters
+    s32 fontId;
+    float lineCompression;
+    bool extraParagraphSpacing;
+    u16 viewportWidth;
+    u16 vieportHeight;
+    u16 pageCount;
+    u32 lutOffset;
+    
+    Page page[pageCount];
+    
+    // Validate LUT offset alignment
+    u32 currentOffset = $;
+    if (currentOffset != lutOffset) {
+        std::warning(std::format("LUT offset mismatch: expected 0x{:X}, got 0x{:X}", lutOffset, currentOffset));
+    }
+    
+    // Lookup Tables
+    u32 lut[pageCount];
+};
+
+// === File Parsing ===
+
+SectionBin book @ 0x00;
+
+// Validate we've consumed the entire file
+u32 fileSize = std::mem::size();
+u32 parsedSize = $;
+
+if (parsedSize != fileSize) {
+    std::warning(std::format("Unparsed data detected: {} bytes remaining at offset 0x{:X}", fileSize - parsedSize, parsedSize));
+}
+```

docs/webserver.md

@@ -170,6 +170,40 @@ This is useful for organizing your ebooks by genre, author, or series.
 
 ---
 
+## Command Line File Management
+
+For power users, you can manage files directly from your terminal using `curl` while the device is in File Upload mode. 
+
+### Uploading a File
+To upload a file to the root directory, use the following command:
+```bash
+curl -F "file=@book.epub" "http://crosspoint.local/upload?path=/"
+```
+
+* **`-F "file=@filename"`**: Points to the local file on your computer.
+* **`path=/`**: The destination folder on the device SD card.
+
+### Deleting a File
+
+To delete a specific file, provide the full path on the SD card:
+
+```bash
+curl -F "path=/folder/file.epub" "http://crosspoint.local/delete"
+```
+
+### Advanced Flags
+
+For more reliable transfers of large EPUB files, consider adding these flags:
+
+* `-#`: Shows a simple progress bar.
+* `--connect-timeout 30`: Limits how long curl waits to establish a connection (in seconds).
+* `--max-time 300`: Sets a maximum duration for the entire transfer (5 minutes).
+
+> [!NOTE]
+> These examples use `crosspoint.local`. If your network does not support mDNS or the address does not resolve, replace it with the specific **IP Address** displayed on your device screen (e.g., `http://192.168.1.102/`).
+
+---
+
 ## Troubleshooting
 
 ### Cannot See the Device on the Network

lib/EpdFont/EpdFontFamily.cpp

@@ -1,6 +1,6 @@
 #include "EpdFontFamily.h"
 
-const EpdFont* EpdFontFamily::getFont(const EpdFontStyle style) const {
+const EpdFont* EpdFontFamily::getFont(const Style style) const {
   if (style == BOLD && bold) {
     return bold;
   }
@@ -22,16 +22,16 @@ const EpdFont* EpdFontFamily::getFont(const EpdFontStyle style) const {
   return regular;
 }
 
-void EpdFontFamily::getTextDimensions(const char* string, int* w, int* h, const EpdFontStyle style) const {
+void EpdFontFamily::getTextDimensions(const char* string, int* w, int* h, const Style style) const {
   getFont(style)->getTextDimensions(string, w, h);
 }
 
-bool EpdFontFamily::hasPrintableChars(const char* string, const EpdFontStyle style) const {
+bool EpdFontFamily::hasPrintableChars(const char* string, const Style style) const {
   return getFont(style)->hasPrintableChars(string);
 }
 
-const EpdFontData* EpdFontFamily::getData(const EpdFontStyle style) const { return getFont(style)->data; }
+const EpdFontData* EpdFontFamily::getData(const Style style) const { return getFont(style)->data; }
 
-const EpdGlyph* EpdFontFamily::getGlyph(const uint32_t cp, const EpdFontStyle style) const {
+const EpdGlyph* EpdFontFamily::getGlyph(const uint32_t cp, const Style style) const {
   return getFont(style)->getGlyph(cp);
 };

lib/EpdFont/EpdFontFamily.h

@@ -1,24 +1,24 @@
 #pragma once
 #include "EpdFont.h"
 
-enum EpdFontStyle { REGULAR, BOLD, ITALIC, BOLD_ITALIC };
-
 class EpdFontFamily {
+ public:
+  enum Style : uint8_t { REGULAR = 0, BOLD = 1, ITALIC = 2, BOLD_ITALIC = 3 };
+
+  explicit EpdFontFamily(const EpdFont* regular, const EpdFont* bold = nullptr, const EpdFont* italic = nullptr,
+                         const EpdFont* boldItalic = nullptr)
+      : regular(regular), bold(bold), italic(italic), boldItalic(boldItalic) {}
+  ~EpdFontFamily() = default;
+  void getTextDimensions(const char* string, int* w, int* h, Style style = REGULAR) const;
+  bool hasPrintableChars(const char* string, Style style = REGULAR) const;
+  const EpdFontData* getData(Style style = REGULAR) const;
+  const EpdGlyph* getGlyph(uint32_t cp, Style style = REGULAR) const;
+
+ private:
   const EpdFont* regular;
   const EpdFont* bold;
   const EpdFont* italic;
   const EpdFont* boldItalic;
 
-  const EpdFont* getFont(EpdFontStyle style) const;
+  const EpdFont* getFont(Style style) const;
-
- public:
-  explicit EpdFontFamily(const EpdFont* regular, const EpdFont* bold = nullptr, const EpdFont* italic = nullptr,
-                         const EpdFont* boldItalic = nullptr)
-      : regular(regular), bold(bold), italic(italic), boldItalic(boldItalic) {}
-  ~EpdFontFamily() = default;
-  void getTextDimensions(const char* string, int* w, int* h, EpdFontStyle style = REGULAR) const;
-  bool hasPrintableChars(const char* string, EpdFontStyle style = REGULAR) const;
-
-  const EpdFontData* getData(EpdFontStyle style = REGULAR) const;
-  const EpdGlyph* getGlyph(uint32_t cp, EpdFontStyle style = REGULAR) const;
 };

lib/Epub/Epub.cpp

@@ -8,6 +8,7 @@
 
 #include "Epub/parsers/ContainerParser.h"
 #include "Epub/parsers/ContentOpfParser.h"
+#include "Epub/parsers/TocNavParser.h"
 #include "Epub/parsers/TocNcxParser.h"
 
 bool Epub::findContentOpfFile(std::string* contentOpfFile) const {
@@ -80,6 +81,10 @@ bool Epub::parseContentOpf(BookMetadataCache::BookMetadata& bookMetadata) {
     tocNcxItem = opfParser.tocNcxPath;
   }
 
+  if (!opfParser.tocNavPath.empty()) {
+    tocNavItem = opfParser.tocNavPath;
+  }
+
   Serial.printf("[%lu] [EBP] Successfully parsed content.opf\n", millis());
   return true;
 }
@@ -141,6 +146,63 @@ bool Epub::parseTocNcxFile() const {
   return true;
 }
 
+bool Epub::parseTocNavFile() const {
+  // the nav file should have been specified in the content.opf file (EPUB 3)
+  if (tocNavItem.empty()) {
+    Serial.printf("[%lu] [EBP] No nav file specified\n", millis());
+    return false;
+  }
+
+  Serial.printf("[%lu] [EBP] Parsing toc nav file: %s\n", millis(), tocNavItem.c_str());
+
+  const auto tmpNavPath = getCachePath() + "/toc.nav";
+  FsFile tempNavFile;
+  if (!SdMan.openFileForWrite("EBP", tmpNavPath, tempNavFile)) {
+    return false;
+  }
+  readItemContentsToStream(tocNavItem, tempNavFile, 1024);
+  tempNavFile.close();
+  if (!SdMan.openFileForRead("EBP", tmpNavPath, tempNavFile)) {
+    return false;
+  }
+  const auto navSize = tempNavFile.size();
+
+  // Note: We can't use `contentBasePath` here as the nav file may be in a different folder to the content.opf
+  // and the HTMLX nav file will have hrefs relative to itself
+  const std::string navContentBasePath = tocNavItem.substr(0, tocNavItem.find_last_of('/') + 1);
+  TocNavParser navParser(navContentBasePath, navSize, bookMetadataCache.get());
+
+  if (!navParser.setup()) {
+    Serial.printf("[%lu] [EBP] Could not setup toc nav parser\n", millis());
+    return false;
+  }
+
+  const auto navBuffer = static_cast<uint8_t*>(malloc(1024));
+  if (!navBuffer) {
+    Serial.printf("[%lu] [EBP] Could not allocate memory for toc nav parser\n", millis());
+    return false;
+  }
+
+  while (tempNavFile.available()) {
+    const auto readSize = tempNavFile.read(navBuffer, 1024);
+    const auto processedSize = navParser.write(navBuffer, readSize);
+
+    if (processedSize != readSize) {
+      Serial.printf("[%lu] [EBP] Could not process all toc nav data\n", millis());
+      free(navBuffer);
+      tempNavFile.close();
+      return false;
+    }
+  }
+
+  free(navBuffer);
+  tempNavFile.close();
+  SdMan.remove(tmpNavPath.c_str());
+
+  Serial.printf("[%lu] [EBP] Parsed TOC nav items\n", millis());
+  return true;
+}
+
 // load in the meta data for the epub file
 bool Epub::load(const bool buildIfMissing) {
   Serial.printf("[%lu] [EBP] Loading ePub: %s\n", millis(), filepath.c_str());
@@ -184,15 +246,31 @@ bool Epub::load(const bool buildIfMissing) {
     return false;
   }
 
-  // TOC Pass
+  // TOC Pass - try EPUB 3 nav first, fall back to NCX
   if (!bookMetadataCache->beginTocPass()) {
     Serial.printf("[%lu] [EBP] Could not begin writing toc pass\n", millis());
     return false;
   }
-  if (!parseTocNcxFile()) {
+
-    Serial.printf("[%lu] [EBP] Could not parse toc\n", millis());
+  bool tocParsed = false;
-    return false;
+
+  // Try EPUB 3 nav document first (preferred)
+  if (!tocNavItem.empty()) {
+    Serial.printf("[%lu] [EBP] Attempting to parse EPUB 3 nav document\n", millis());
+    tocParsed = parseTocNavFile();
   }
+
+  // Fall back to NCX if nav parsing failed or wasn't available
+  if (!tocParsed && !tocNcxItem.empty()) {
+    Serial.printf("[%lu] [EBP] Falling back to NCX TOC\n", millis());
+    tocParsed = parseTocNcxFile();
+  }
+
+  if (!tocParsed) {
+    Serial.printf("[%lu] [EBP] Warning: Could not parse any TOC format\n", millis());
+    // Continue anyway - book will work without TOC
+  }
+
   if (!bookMetadataCache->endTocPass()) {
     Serial.printf("[%lu] [EBP] Could not end writing toc pass\n", millis());
     return false;
@@ -270,11 +348,14 @@ const std::string& Epub::getAuthor() const {
   return bookMetadataCache->coreMetadata.author;
 }
 
-std::string Epub::getCoverBmpPath() const { return cachePath + "/cover.bmp"; }
+std::string Epub::getCoverBmpPath(bool cropped) const {
+  const auto coverFileName = "cover" + cropped ? "_crop" : "";
+  return cachePath + "/" + coverFileName + ".bmp";
+}
 
-bool Epub::generateCoverBmp() const {
+bool Epub::generateCoverBmp(bool cropped) const {
   // Already generated, return true
-  if (SdMan.exists(getCoverBmpPath().c_str())) {
+  if (SdMan.exists(getCoverBmpPath(cropped).c_str())) {
     return true;
   }
 
@@ -306,7 +387,7 @@ bool Epub::generateCoverBmp() const {
     }
 
     FsFile coverBmp;
-    if (!SdMan.openFileForWrite("EBP", getCoverBmpPath(), coverBmp)) {
+    if (!SdMan.openFileForWrite("EBP", getCoverBmpPath(cropped), coverBmp)) {
       coverJpg.close();
       return false;
     }
@@ -317,7 +398,7 @@ bool Epub::generateCoverBmp() const {
 
     if (!success) {
       Serial.printf("[%lu] [EBP] Failed to generate BMP from JPG cover image\n", millis());
-      SdMan.remove(getCoverBmpPath().c_str());
+      SdMan.remove(getCoverBmpPath(cropped).c_str());
     }
     Serial.printf("[%lu] [EBP] Generated BMP from JPG cover image, success: %s\n", millis(), success ? "yes" : "no");
     return success;

lib/Epub/Epub.h

@@ -12,8 +12,10 @@
 class ZipFile;
 
 class Epub {
-  // the ncx file
+  // the ncx file (EPUB 2)
   std::string tocNcxItem;
+  // the nav file (EPUB 3)
+  std::string tocNavItem;
   // where is the EPUBfile?
   std::string filepath;
   // the base path for items in the EPUB file
@@ -26,6 +28,7 @@ class Epub {
   bool findContentOpfFile(std::string* contentOpfFile) const;
   bool parseContentOpf(BookMetadataCache::BookMetadata& bookMetadata);
   bool parseTocNcxFile() const;
+  bool parseTocNavFile() const;
 
  public:
   explicit Epub(std::string filepath, const std::string& cacheDir) : filepath(std::move(filepath)) {
@@ -41,8 +44,8 @@ class Epub {
   const std::string& getPath() const;
   const std::string& getTitle() const;
   const std::string& getAuthor() const;
-  std::string getCoverBmpPath() const;
+  std::string getCoverBmpPath(bool cropped = false) const;
-  bool generateCoverBmp() const;
+  bool generateCoverBmp(bool cropped = false) const;
   uint8_t* readItemContentsToBytes(const std::string& itemHref, size_t* size = nullptr,
                                    bool trailingNullByte = false) const;
   bool readItemContentsToStream(const std::string& itemHref, Print& out, size_t chunkSize) const;

lib/Epub/Epub/BookMetadataCache.cpp

@@ -9,7 +9,7 @@
 #include "FsHelpers.h"
 
 namespace {
-constexpr uint8_t BOOK_CACHE_VERSION = 3;
+constexpr uint8_t BOOK_CACHE_VERSION = 4;
 constexpr char bookBinFile[] = "/book.bin";
 constexpr char tmpSpineBinFile[] = "/spine.bin.tmp";
 constexpr char tmpTocBinFile[] = "/toc.bin.tmp";

lib/Epub/Epub/Page.cpp

@@ -32,7 +32,7 @@ void Page::render(GfxRenderer& renderer, const int fontId, const int xOffset, co
 }
 
 bool Page::serialize(FsFile& file) const {
-  const uint32_t count = elements.size();
+  const uint16_t count = elements.size();
   serialization::writePod(file, count);
 
   for (const auto& el : elements) {
@@ -49,10 +49,10 @@ bool Page::serialize(FsFile& file) const {
 std::unique_ptr<Page> Page::deserialize(FsFile& file) {
   auto page = std::unique_ptr<Page>(new Page());
 
-  uint32_t count;
+  uint16_t count;
   serialization::readPod(file, count);
 
-  for (uint32_t i = 0; i < count; i++) {
+  for (uint16_t i = 0; i < count; i++) {
     uint8_t tag;
     serialization::readPod(file, tag);
 

lib/Epub/Epub/ParsedText.cpp

@@ -10,7 +10,7 @@
 
 constexpr int MAX_COST = std::numeric_limits<int>::max();
 
-void ParsedText::addWord(std::string word, const EpdFontStyle fontStyle) {
+void ParsedText::addWord(std::string word, const EpdFontFamily::Style fontStyle) {
   if (word.empty()) return;
 
   words.push_back(std::move(word));
@@ -18,7 +18,7 @@ void ParsedText::addWord(std::string word, const EpdFontStyle fontStyle) {
 }
 
 // Consumes data to minimize memory usage
-void ParsedText::layoutAndExtractLines(const GfxRenderer& renderer, const int fontId, const int viewportWidth,
+void ParsedText::layoutAndExtractLines(const GfxRenderer& renderer, const int fontId, const uint16_t viewportWidth,
                                        const std::function<void(std::shared_ptr<TextBlock>)>& processLine,
                                        const bool includeLastLine) {
   if (words.empty()) {
@@ -188,7 +188,7 @@ void ParsedText::extractLine(const size_t breakIndex, const int pageWidth, const
   // *** CRITICAL STEP: CONSUME DATA USING SPLICE ***
   std::list<std::string> lineWords;
   lineWords.splice(lineWords.begin(), words, words.begin(), wordEndIt);
-  std::list<EpdFontStyle> lineWordStyles;
+  std::list<EpdFontFamily::Style> lineWordStyles;
   lineWordStyles.splice(lineWordStyles.begin(), wordStyles, wordStyles.begin(), wordStyleEndIt);
 
   processLine(std::make_shared<TextBlock>(std::move(lineWords), std::move(lineXPos), std::move(lineWordStyles), style));

lib/Epub/Epub/ParsedText.h

@@ -14,8 +14,8 @@ class GfxRenderer;
 
 class ParsedText {
   std::list<std::string> words;
-  std::list<EpdFontStyle> wordStyles;
+  std::list<EpdFontFamily::Style> wordStyles;
-  TextBlock::BLOCK_STYLE style;
+  TextBlock::Style style;
   bool extraParagraphSpacing;
 
   std::vector<size_t> computeLineBreaks(int pageWidth, int spaceWidth, const std::vector<uint16_t>& wordWidths) const;
@@ -25,16 +25,16 @@ class ParsedText {
   std::vector<uint16_t> calculateWordWidths(const GfxRenderer& renderer, int fontId);
 
  public:
-  explicit ParsedText(const TextBlock::BLOCK_STYLE style, const bool extraParagraphSpacing)
+  explicit ParsedText(const TextBlock::Style style, const bool extraParagraphSpacing)
       : style(style), extraParagraphSpacing(extraParagraphSpacing) {}
   ~ParsedText() = default;
 
-  void addWord(std::string word, EpdFontStyle fontStyle);
+  void addWord(std::string word, EpdFontFamily::Style fontStyle);
-  void setStyle(const TextBlock::BLOCK_STYLE style) { this->style = style; }
+  void setStyle(const TextBlock::Style style) { this->style = style; }
-  TextBlock::BLOCK_STYLE getStyle() const { return style; }
+  TextBlock::Style getStyle() const { return style; }
   size_t size() const { return words.size(); }
   bool isEmpty() const { return words.empty(); }
-  void layoutAndExtractLines(const GfxRenderer& renderer, int fontId, int viewportWidth,
+  void layoutAndExtractLines(const GfxRenderer& renderer, int fontId, uint16_t viewportWidth,
                              const std::function<void(std::shared_ptr<TextBlock>)>& processLine,
                              bool includeLastLine = true);
 };

lib/Epub/Epub/Section.cpp

@@ -7,9 +7,9 @@
 #include "parsers/ChapterHtmlSlimParser.h"
 
 namespace {
-constexpr uint8_t SECTION_FILE_VERSION = 7;
+constexpr uint8_t SECTION_FILE_VERSION = 9;
-constexpr uint32_t HEADER_SIZE = sizeof(uint8_t) + sizeof(int) + sizeof(float) + sizeof(bool) + sizeof(int) +
+constexpr uint32_t HEADER_SIZE = sizeof(uint8_t) + sizeof(int) + sizeof(float) + sizeof(bool) + sizeof(uint8_t) +
-                                 sizeof(int) + sizeof(int) + sizeof(uint32_t);
+                                 sizeof(uint16_t) + sizeof(uint16_t) + sizeof(uint16_t) + sizeof(uint32_t);
 }  // namespace
 
 uint32_t Section::onPageComplete(std::unique_ptr<Page> page) {
@@ -30,19 +30,21 @@ uint32_t Section::onPageComplete(std::unique_ptr<Page> page) {
 }
 
 void Section::writeSectionFileHeader(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
-                                     const int viewportWidth, const int viewportHeight) {
+                                     const uint8_t paragraphAlignment, const uint16_t viewportWidth,
+                                     const uint16_t viewportHeight) {
   if (!file) {
     Serial.printf("[%lu] [SCT] File not open for writing header\n", millis());
     return;
   }
   static_assert(HEADER_SIZE == sizeof(SECTION_FILE_VERSION) + sizeof(fontId) + sizeof(lineCompression) +
-                                   sizeof(extraParagraphSpacing) + sizeof(viewportWidth) + sizeof(viewportHeight) +
+                                   sizeof(extraParagraphSpacing) + sizeof(paragraphAlignment) + sizeof(viewportWidth) +
-                                   sizeof(pageCount) + sizeof(uint32_t),
+                                   sizeof(viewportHeight) + sizeof(pageCount) + sizeof(uint32_t),
                 "Header size mismatch");
   serialization::writePod(file, SECTION_FILE_VERSION);
   serialization::writePod(file, fontId);
   serialization::writePod(file, lineCompression);
   serialization::writePod(file, extraParagraphSpacing);
+  serialization::writePod(file, paragraphAlignment);
   serialization::writePod(file, viewportWidth);
   serialization::writePod(file, viewportHeight);
   serialization::writePod(file, pageCount);  // Placeholder for page count (will be initially 0 when written)
@@ -50,7 +52,8 @@ void Section::writeSectionFileHeader(const int fontId, const float lineCompressi
 }
 
 bool Section::loadSectionFile(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
-                              const int viewportWidth, const int viewportHeight) {
+                              const uint8_t paragraphAlignment, const uint16_t viewportWidth,
+                              const uint16_t viewportHeight) {
   if (!SdMan.openFileForRead("SCT", filePath, file)) {
     return false;
   }
@@ -66,18 +69,21 @@ bool Section::loadSectionFile(const int fontId, const float lineCompression, con
       return false;
     }
 
-    int fileFontId, fileViewportWidth, fileViewportHeight;
+    int fileFontId;
+    uint16_t fileViewportWidth, fileViewportHeight;
     float fileLineCompression;
     bool fileExtraParagraphSpacing;
+    uint8_t fileParagraphAlignment;
     serialization::readPod(file, fileFontId);
     serialization::readPod(file, fileLineCompression);
     serialization::readPod(file, fileExtraParagraphSpacing);
+    serialization::readPod(file, fileParagraphAlignment);
     serialization::readPod(file, fileViewportWidth);
     serialization::readPod(file, fileViewportHeight);
 
     if (fontId != fileFontId || lineCompression != fileLineCompression ||
-        extraParagraphSpacing != fileExtraParagraphSpacing || viewportWidth != fileViewportWidth ||
+        extraParagraphSpacing != fileExtraParagraphSpacing || paragraphAlignment != fileParagraphAlignment ||
-        viewportHeight != fileViewportHeight) {
+        viewportWidth != fileViewportWidth || viewportHeight != fileViewportHeight) {
       file.close();
       Serial.printf("[%lu] [SCT] Deserialization failed: Parameters do not match\n", millis());
       clearCache();
@@ -108,8 +114,8 @@ bool Section::clearCache() const {
 }
 
 bool Section::createSectionFile(const int fontId, const float lineCompression, const bool extraParagraphSpacing,
-                                const int viewportWidth, const int viewportHeight,
+                                const uint8_t paragraphAlignment, const uint16_t viewportWidth,
-                                const std::function<void()>& progressSetupFn,
+                                const uint16_t viewportHeight, const std::function<void()>& progressSetupFn,
                                 const std::function<void(int)>& progressFn) {
   constexpr uint32_t MIN_SIZE_FOR_PROGRESS = 50 * 1024;  // 50KB
   const auto localPath = epub->getSpineItem(spineIndex).href;
@@ -165,11 +171,13 @@ bool Section::createSectionFile(const int fontId, const float lineCompression, c
   if (!SdMan.openFileForWrite("SCT", filePath, file)) {
     return false;
   }
-  writeSectionFileHeader(fontId, lineCompression, extraParagraphSpacing, viewportWidth, viewportHeight);
+  writeSectionFileHeader(fontId, lineCompression, extraParagraphSpacing, paragraphAlignment, viewportWidth,
+                         viewportHeight);
   std::vector<uint32_t> lut = {};
 
   ChapterHtmlSlimParser visitor(
-      tmpHtmlPath, renderer, fontId, lineCompression, extraParagraphSpacing, viewportWidth, viewportHeight,
+      tmpHtmlPath, renderer, fontId, lineCompression, extraParagraphSpacing, paragraphAlignment, viewportWidth,
+      viewportHeight,
       [this, &lut](std::unique_ptr<Page> page) { lut.emplace_back(this->onPageComplete(std::move(page))); },
       progressFn);
   success = visitor.parseAndBuildPages();

lib/Epub/Epub/Section.h

@@ -14,12 +14,12 @@ class Section {
   std::string filePath;
   FsFile file;
 
-  void writeSectionFileHeader(int fontId, float lineCompression, bool extraParagraphSpacing, int viewportWidth,
+  void writeSectionFileHeader(int fontId, float lineCompression, bool extraParagraphSpacing, uint8_t paragraphAlignment,
-                              int viewportHeight);
+                              uint16_t viewportWidth, uint16_t viewportHeight);
   uint32_t onPageComplete(std::unique_ptr<Page> page);
 
  public:
-  int pageCount = 0;
+  uint16_t pageCount = 0;
   int currentPage = 0;
 
   explicit Section(const std::shared_ptr<Epub>& epub, const int spineIndex, GfxRenderer& renderer)
@@ -28,11 +28,12 @@ class Section {
         renderer(renderer),
         filePath(epub->getCachePath() + "/sections/" + std::to_string(spineIndex) + ".bin") {}
   ~Section() = default;
-  bool loadSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, int viewportWidth,
+  bool loadSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, uint8_t paragraphAlignment,
-                       int viewportHeight);
+                       uint16_t viewportWidth, uint16_t viewportHeight);
   bool clearCache() const;
-  bool createSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, int viewportWidth,
+  bool createSectionFile(int fontId, float lineCompression, bool extraParagraphSpacing, uint8_t paragraphAlignment,
-                         int viewportHeight, const std::function<void()>& progressSetupFn = nullptr,
+                         uint16_t viewportWidth, uint16_t viewportHeight,
+                         const std::function<void()>& progressSetupFn = nullptr,
                          const std::function<void(int)>& progressFn = nullptr);
   std::unique_ptr<Page> loadPageFromSectionFile();
 };

lib/Epub/Epub/blocks/TextBlock.cpp

@@ -32,7 +32,7 @@ bool TextBlock::serialize(FsFile& file) const {
   }
 
   // Word data
-  serialization::writePod(file, static_cast<uint32_t>(words.size()));
+  serialization::writePod(file, static_cast<uint16_t>(words.size()));
   for (const auto& w : words) serialization::writeString(file, w);
   for (auto x : wordXpos) serialization::writePod(file, x);
   for (auto s : wordStyles) serialization::writePod(file, s);
@@ -44,11 +44,11 @@ bool TextBlock::serialize(FsFile& file) const {
 }
 
 std::unique_ptr<TextBlock> TextBlock::deserialize(FsFile& file) {
-  uint32_t wc;
+  uint16_t wc;
   std::list<std::string> words;
   std::list<uint16_t> wordXpos;
-  std::list<EpdFontStyle> wordStyles;
+  std::list<EpdFontFamily::Style> wordStyles;
-  BLOCK_STYLE style;
+  Style style;
 
   // Word count
   serialization::readPod(file, wc);

lib/Epub/Epub/blocks/TextBlock.h

@@ -8,10 +8,10 @@
 
 #include "Block.h"
 
-// represents a block of words in the html document
+// Represents a line of text on a page
 class TextBlock final : public Block {
  public:
-  enum BLOCK_STYLE : uint8_t {
+  enum Style : uint8_t {
     JUSTIFIED = 0,
     LEFT_ALIGN = 1,
     CENTER_ALIGN = 2,
@@ -21,16 +21,16 @@ class TextBlock final : public Block {
  private:
   std::list<std::string> words;
   std::list<uint16_t> wordXpos;
-  std::list<EpdFontStyle> wordStyles;
+  std::list<EpdFontFamily::Style> wordStyles;
-  BLOCK_STYLE style;
+  Style style;
 
  public:
-  explicit TextBlock(std::list<std::string> words, std::list<uint16_t> word_xpos, std::list<EpdFontStyle> word_styles,
+  explicit TextBlock(std::list<std::string> words, std::list<uint16_t> word_xpos,
-                     const BLOCK_STYLE style)
+                     std::list<EpdFontFamily::Style> word_styles, const Style style)
       : words(std::move(words)), wordXpos(std::move(word_xpos)), wordStyles(std::move(word_styles)), style(style) {}
   ~TextBlock() override = default;
-  void setStyle(const BLOCK_STYLE style) { this->style = style; }
+  void setStyle(const Style style) { this->style = style; }
-  BLOCK_STYLE getStyle() const { return style; }
+  Style getStyle() const { return style; }
   bool isEmpty() override { return words.empty(); }
   void layout(GfxRenderer& renderer) override {};
   // given a renderer works out where to break the words into lines

lib/Epub/Epub/htmlEntities.cpp

@@ -1,163 +0,0 @@
-// from
-// https://github.com/atomic14/diy-esp32-epub-reader/blob/2c2f57fdd7e2a788d14a0bcb26b9e845a47aac42/lib/Epub/RubbishHtmlParser/htmlEntities.cpp
-
-#include "htmlEntities.h"
-
-#include <cstring>
-#include <unordered_map>
-
-const int MAX_ENTITY_LENGTH = 10;
-
-// Use book: entities_ww2.epub to test this (Page 7: Entities parser test)
-// Note the supported keys are only in lowercase
-// Store the mappings in a unordered hash map
-static std::unordered_map<std::string, std::string> entity_lookup(
-    {{"&quot;", "\""},  {"&frasl;", "⁄"},   {"&amp;", "&"},      {"&lt;", "<"},     {"&gt;", ">"},
-     {"&Agrave;", "À"}, {"&Aacute;", "Á"},  {"&Acirc;", "Â"},    {"&Atilde;", "Ã"}, {"&Auml;", "Ä"},
-     {"&Aring;", "Å"},  {"&AElig;", "Æ"},   {"&Ccedil;", "Ç"},   {"&Egrave;", "È"}, {"&Eacute;", "É"},
-     {"&Ecirc;", "Ê"},  {"&Euml;", "Ë"},    {"&Igrave;", "Ì"},   {"&Iacute;", "Í"}, {"&Icirc;", "Î"},
-     {"&Iuml;", "Ï"},   {"&ETH;", "Ð"},     {"&Ntilde;", "Ñ"},   {"&Ograve;", "Ò"}, {"&Oacute;", "Ó"},
-     {"&Ocirc;", "Ô"},  {"&Otilde;", "Õ"},  {"&Ouml;", "Ö"},     {"&Oslash;", "Ø"}, {"&Ugrave;", "Ù"},
-     {"&Uacute;", "Ú"}, {"&Ucirc;", "Û"},   {"&Uuml;", "Ü"},     {"&Yacute;", "Ý"}, {"&THORN;", "Þ"},
-     {"&szlig;", "ß"},  {"&agrave;", "à"},  {"&aacute;", "á"},   {"&acirc;", "â"},  {"&atilde;", "ã"},
-     {"&auml;", "ä"},   {"&aring;", "å"},   {"&aelig;", "æ"},    {"&ccedil;", "ç"}, {"&egrave;", "è"},
-     {"&eacute;", "é"}, {"&ecirc;", "ê"},   {"&euml;", "ë"},     {"&igrave;", "ì"}, {"&iacute;", "í"},
-     {"&icirc;", "î"},  {"&iuml;", "ï"},    {"&eth;", "ð"},      {"&ntilde;", "ñ"}, {"&ograve;", "ò"},
-     {"&oacute;", "ó"}, {"&ocirc;", "ô"},   {"&otilde;", "õ"},   {"&ouml;", "ö"},   {"&oslash;", "ø"},
-     {"&ugrave;", "ù"}, {"&uacute;", "ú"},  {"&ucirc;", "û"},    {"&uuml;", "ü"},   {"&yacute;", "ý"},
-     {"&thorn;", "þ"},  {"&yuml;", "ÿ"},    {"&nbsp;", " "},     {"&iexcl;", "¡"},  {"&cent;", "¢"},
-     {"&pound;", "£"},  {"&curren;", "¤"},  {"&yen;", "¥"},      {"&brvbar;", "¦"}, {"&sect;", "§"},
-     {"&uml;", "¨"},    {"&copy;", "©"},    {"&ordf;", "ª"},     {"&laquo;", "«"},  {"&not;", "¬"},
-     {"&shy;", "­"},    {"&reg;", "®"},     {"&macr;", "¯"},     {"&deg;", "°"},    {"&plusmn;", "±"},
-     {"&sup2;", "²"},   {"&sup3;", "³"},    {"&acute;", "´"},    {"&micro;", "µ"},  {"&para;", "¶"},
-     {"&cedil;", "¸"},  {"&sup1;", "¹"},    {"&ordm;", "º"},     {"&raquo;", "»"},  {"&frac14;", "¼"},
-     {"&frac12;", "½"}, {"&frac34;", "¾"},  {"&iquest;", "¿"},   {"&times;", "×"},  {"&divide;", "÷"},
-     {"&forall;", "∀"}, {"&part;", "∂"},    {"&exist;", "∃"},    {"&empty;", "∅"},  {"&nabla;", "∇"},
-     {"&isin;", "∈"},   {"&notin;", "∉"},   {"&ni;", "∋"},       {"&prod;", "∏"},   {"&sum;", "∑"},
-     {"&minus;", "−"},  {"&lowast;", "∗"},  {"&radic;", "√"},    {"&prop;", "∝"},   {"&infin;", "∞"},
-     {"&ang;", "∠"},    {"&and;", "∧"},     {"&or;", "∨"},       {"&cap;", "∩"},    {"&cup;", "∪"},
-     {"&int;", "∫"},    {"&there4;", "∴"},  {"&sim;", "∼"},      {"&cong;", "≅"},   {"&asymp;", "≈"},
-     {"&ne;", "≠"},     {"&equiv;", "≡"},   {"&le;", "≤"},       {"&ge;", "≥"},     {"&sub;", "⊂"},
-     {"&sup;", "⊃"},    {"&nsub;", "⊄"},    {"&sube;", "⊆"},     {"&supe;", "⊇"},   {"&oplus;", "⊕"},
-     {"&otimes;", "⊗"}, {"&perp;", "⊥"},    {"&sdot;", "⋅"},     {"&Alpha;", "Α"},  {"&Beta;", "Β"},
-     {"&Gamma;", "Γ"},  {"&Delta;", "Δ"},   {"&Epsilon;", "Ε"},  {"&Zeta;", "Ζ"},   {"&Eta;", "Η"},
-     {"&Theta;", "Θ"},  {"&Iota;", "Ι"},    {"&Kappa;", "Κ"},    {"&Lambda;", "Λ"}, {"&Mu;", "Μ"},
-     {"&Nu;", "Ν"},     {"&Xi;", "Ξ"},      {"&Omicron;", "Ο"},  {"&Pi;", "Π"},     {"&Rho;", "Ρ"},
-     {"&Sigma;", "Σ"},  {"&Tau;", "Τ"},     {"&Upsilon;", "Υ"},  {"&Phi;", "Φ"},    {"&Chi;", "Χ"},
-     {"&Psi;", "Ψ"},    {"&Omega;", "Ω"},   {"&alpha;", "α"},    {"&beta;", "β"},   {"&gamma;", "γ"},
-     {"&delta;", "δ"},  {"&epsilon;", "ε"}, {"&zeta;", "ζ"},     {"&eta;", "η"},    {"&theta;", "θ"},
-     {"&iota;", "ι"},   {"&kappa;", "κ"},   {"&lambda;", "λ"},   {"&mu;", "μ"},     {"&nu;", "ν"},
-     {"&xi;", "ξ"},     {"&omicron;", "ο"}, {"&pi;", "π"},       {"&rho;", "ρ"},    {"&sigmaf;", "ς"},
-     {"&sigma;", "σ"},  {"&tau;", "τ"},     {"&upsilon;", "υ"},  {"&phi;", "φ"},    {"&chi;", "χ"},
-     {"&psi;", "ψ"},    {"&omega;", "ω"},   {"&thetasym;", "ϑ"}, {"&upsih;", "ϒ"},  {"&piv;", "ϖ"},
-     {"&OElig;", "Œ"},  {"&oelig;", "œ"},   {"&Scaron;", "Š"},   {"&scaron;", "š"}, {"&Yuml;", "Ÿ"},
-     {"&fnof;", "ƒ"},   {"&circ;", "ˆ"},    {"&tilde;", "˜"},    {"&ensp;", ""},    {"&emsp;", ""},
-     {"&thinsp;", ""},  {"&zwnj;", "‌"},  {"&zwj;", "‍"},    {"&lrm;", "‎"},  {"&rlm;", "‏"},
-     {"&ndash;", "–"},  {"&mdash;", "—"},   {"&lsquo;", "‘"},    {"&rsquo;", "’"},  {"&sbquo;", "‚"},
-     {"&ldquo;", "“"},  {"&rdquo;", "”"},   {"&bdquo;", "„"},    {"&dagger;", "†"}, {"&Dagger;", "‡"},
-     {"&bull;", "•"},   {"&hellip;", "…"},  {"&permil;", "‰"},   {"&prime;", "′"},  {"&Prime;", "″"},
-     {"&lsaquo;", "‹"}, {"&rsaquo;", "›"},  {"&oline;", "‾"},    {"&euro;", "€"},   {"&trade;", "™"},
-     {"&larr;", "←"},   {"&uarr;", "↑"},    {"&rarr;", "→"},     {"&darr;", "↓"},   {"&harr;", "↔"},
-     {"&crarr;", "↵"},  {"&lceil;", "⌈"},   {"&rceil;", "⌉"},    {"&lfloor;", "⌊"}, {"&rfloor;", "⌋"},
-     {"&loz;", "◊"},    {"&spades;", "♠"},  {"&clubs;", "♣"},    {"&hearts;", "♥"}, {"&diams;", "♦"}});
-
-// converts from a unicode code point to the utf8 equivalent
-void convert_to_utf8(const int code, std::string& res) {
-  // convert to a utf8 sequence
-  if (code < 0x80) {
-    res += static_cast<char>(code);
-  } else if (code < 0x800) {
-    res += static_cast<char>(0xc0 | (code >> 6));
-    res += static_cast<char>(0x80 | (code & 0x3f));
-  } else if (code < 0x10000) {
-    res += static_cast<char>(0xe0 | (code >> 12));
-    res += static_cast<char>(0x80 | ((code >> 6) & 0x3f));
-    res += static_cast<char>(0x80 | (code & 0x3f));
-  } else if (code < 0x200000) {
-    res += static_cast<char>(0xf0 | (code >> 18));
-    res += static_cast<char>(0x80 | ((code >> 12) & 0x3f));
-    res += static_cast<char>(0x80 | ((code >> 6) & 0x3f));
-    res += static_cast<char>(0x80 | (code & 0x3f));
-  } else if (code < 0x4000000) {
-    res += static_cast<char>(0xf8 | (code >> 24));
-    res += static_cast<char>(0x80 | ((code >> 18) & 0x3f));
-    res += static_cast<char>(0x80 | ((code >> 12) & 0x3f));
-    res += static_cast<char>(0x80 | ((code >> 6) & 0x3f));
-    res += static_cast<char>(0x80 | (code & 0x3f));
-  } else if (code < 0x80000000) {
-    res += static_cast<char>(0xfc | (code >> 30));
-    res += static_cast<char>(0x80 | ((code >> 24) & 0x3f));
-    res += static_cast<char>(0x80 | ((code >> 18) & 0x3f));
-    res += static_cast<char>(0x80 | ((code >> 12) & 0x3f));
-    res += static_cast<char>(0x80 | ((code >> 6) & 0x3f));
-  }
-}
-
-// handles numeric entities - e.g. &#1234; or &#x1234;
-bool process_numeric_entity(const std::string& entity, std::string& res) {
-  int code = 0;
-  // is it hex?
-  if (entity[2] == 'x' || entity[2] == 'X') {
-    // parse the hex code
-    code = strtol(entity.substr(3, entity.size() - 3).c_str(), nullptr, 16);
-  } else {
-    code = strtol(entity.substr(2, entity.size() - 3).c_str(), nullptr, 10);
-  }
-  if (code != 0) {
-    // special handling for nbsp
-    if (code == 0xA0) {
-      res += " ";
-    } else {
-      convert_to_utf8(code, res);
-    }
-    return true;
-  }
-  return false;
-}
-
-// handles named entities - e.g. &amp;
-bool process_string_entity(const std::string& entity, std::string& res) {
-  // it's a named entity - find it in the lookup table
-  // find it in the map
-  const auto it = entity_lookup.find(entity);
-  if (it != entity_lookup.end()) {
-    res += it->second;
-    return true;
-  }
-  return false;
-}
-
-// replace all the entities in the string
-std::string replaceHtmlEntities(const char* text) {
-  std::string res;
-  res.reserve(strlen(text));
-  for (int i = 0; i < strlen(text); ++i) {
-    bool flag = false;
-    // do we have a potential entity?
-    if (text[i] == '&') {
-      // find the end of the entity
-      int j = i + 1;
-      while (j < strlen(text) && text[j] != ';' && j - i < MAX_ENTITY_LENGTH) {
-        j++;
-      }
-      if (j - i > 2) {
-        char entity[j - i + 1];
-        strncpy(entity, text + i, j - i);
-        // is it a numeric code?
-        if (entity[1] == '#') {
-          flag = process_numeric_entity(entity, res);
-        } else {
-          flag = process_string_entity(entity, res);
-        }
-        // skip past the entity if we successfully decoded it
-        if (flag) {
-          i = j;
-        }
-      }
-    }
-    if (!flag) {
-      res += text[i];
-    }
-  }
-  return res;
-}

lib/Epub/Epub/htmlEntities.h

@@ -1,7 +0,0 @@
-// from
-// https://github.com/atomic14/diy-esp32-epub-reader/blob/2c2f57fdd7e2a788d14a0bcb26b9e845a47aac42/lib/Epub/RubbishHtmlParser/htmlEntities.cpp
-
-#pragma once
-#include <string>
-
-std::string replaceHtmlEntities(const char* text);

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.cpp

@@ -6,7 +6,6 @@
 #include <expat.h>
 
 #include "../Page.h"
-#include "../htmlEntities.h"
 
 const char* HEADER_TAGS[] = {"h1", "h2", "h3", "h4", "h5", "h6"};
 constexpr int NUM_HEADER_TAGS = sizeof(HEADER_TAGS) / sizeof(HEADER_TAGS[0]);
@@ -42,7 +41,7 @@ bool matches(const char* tag_name, const char* possible_tags[], const int possib
 }
 
 // start a new text block if needed
-void ChapterHtmlSlimParser::startNewTextBlock(const TextBlock::BLOCK_STYLE style) {
+void ChapterHtmlSlimParser::startNewTextBlock(const TextBlock::Style style) {
   if (currentTextBlock) {
     // already have a text block running and it is empty - just reuse it
     if (currentTextBlock->isEmpty()) {
@@ -97,7 +96,7 @@ void XMLCALL ChapterHtmlSlimParser::startElement(void* userData, const XML_Char*
     if (strcmp(name, "br") == 0) {
       self->startNewTextBlock(self->currentTextBlock->getStyle());
     } else {
-      self->startNewTextBlock(TextBlock::JUSTIFIED);
+      self->startNewTextBlock((TextBlock::Style)self->paragraphAlignment);
     }
   } else if (matches(name, BOLD_TAGS, NUM_BOLD_TAGS)) {
     self->boldUntilDepth = std::min(self->boldUntilDepth, self->depth);
@@ -116,13 +115,13 @@ void XMLCALL ChapterHtmlSlimParser::characterData(void* userData, const XML_Char
     return;
   }
 
-  EpdFontStyle fontStyle = REGULAR;
+  EpdFontFamily::Style fontStyle = EpdFontFamily::REGULAR;
   if (self->boldUntilDepth < self->depth && self->italicUntilDepth < self->depth) {
-    fontStyle = BOLD_ITALIC;
+    fontStyle = EpdFontFamily::BOLD_ITALIC;
   } else if (self->boldUntilDepth < self->depth) {
-    fontStyle = BOLD;
+    fontStyle = EpdFontFamily::BOLD;
   } else if (self->italicUntilDepth < self->depth) {
-    fontStyle = ITALIC;
+    fontStyle = EpdFontFamily::ITALIC;
   }
 
   for (int i = 0; i < len; i++) {
@@ -130,17 +129,32 @@ void XMLCALL ChapterHtmlSlimParser::characterData(void* userData, const XML_Char
       // Currently looking at whitespace, if there's anything in the partWordBuffer, flush it
       if (self->partWordBufferIndex > 0) {
         self->partWordBuffer[self->partWordBufferIndex] = '\0';
-        self->currentTextBlock->addWord(std::move(replaceHtmlEntities(self->partWordBuffer)), fontStyle);
+        self->currentTextBlock->addWord(self->partWordBuffer, fontStyle);
         self->partWordBufferIndex = 0;
       }
       // Skip the whitespace char
       continue;
     }
 
+    // Skip soft-hyphen with UTF-8 representation (U+00AD) = 0xC2 0xAD
+    const XML_Char SHY_BYTE_1 = static_cast<XML_Char>(0xC2);
+    const XML_Char SHY_BYTE_2 = static_cast<XML_Char>(0xAD);
+    // 1. Check for the start of the 2-byte Soft Hyphen sequence
+    if (s[i] == SHY_BYTE_1) {
+      // 2. Check if the next byte exists AND if it completes the sequence
+      //    We must check i + 1 < len to prevent reading past the end of the buffer.
+      if ((i + 1 < len) && (s[i + 1] == SHY_BYTE_2)) {
+        // Sequence 0xC2 0xAD found!
+        // Skip the current byte (0xC2) and the next byte (0xAD)
+        i++;       // Increment 'i' one more time to skip the 0xAD byte
+        continue;  // Skip the rest of the loop and move to the next iteration
+      }
+    }
+
     // If we're about to run out of space, then cut the word off and start a new one
     if (self->partWordBufferIndex >= MAX_WORD_SIZE) {
       self->partWordBuffer[self->partWordBufferIndex] = '\0';
-      self->currentTextBlock->addWord(std::move(replaceHtmlEntities(self->partWordBuffer)), fontStyle);
+      self->currentTextBlock->addWord(self->partWordBuffer, fontStyle);
       self->partWordBufferIndex = 0;
     }
 
@@ -172,17 +186,17 @@ void XMLCALL ChapterHtmlSlimParser::endElement(void* userData, const XML_Char* n
         matches(name, BOLD_TAGS, NUM_BOLD_TAGS) || matches(name, ITALIC_TAGS, NUM_ITALIC_TAGS) || self->depth == 1;
 
     if (shouldBreakText) {
-      EpdFontStyle fontStyle = REGULAR;
+      EpdFontFamily::Style fontStyle = EpdFontFamily::REGULAR;
       if (self->boldUntilDepth < self->depth && self->italicUntilDepth < self->depth) {
-        fontStyle = BOLD_ITALIC;
+        fontStyle = EpdFontFamily::BOLD_ITALIC;
       } else if (self->boldUntilDepth < self->depth) {
-        fontStyle = BOLD;
+        fontStyle = EpdFontFamily::BOLD;
       } else if (self->italicUntilDepth < self->depth) {
-        fontStyle = ITALIC;
+        fontStyle = EpdFontFamily::ITALIC;
       }
 
       self->partWordBuffer[self->partWordBufferIndex] = '\0';
-      self->currentTextBlock->addWord(std::move(replaceHtmlEntities(self->partWordBuffer)), fontStyle);
+      self->currentTextBlock->addWord(self->partWordBuffer, fontStyle);
       self->partWordBufferIndex = 0;
     }
   }
@@ -206,7 +220,7 @@ void XMLCALL ChapterHtmlSlimParser::endElement(void* userData, const XML_Char* n
 }
 
 bool ChapterHtmlSlimParser::parseAndBuildPages() {
-  startNewTextBlock(TextBlock::JUSTIFIED);
+  startNewTextBlock((TextBlock::Style)this->paragraphAlignment);
 
   const XML_Parser parser = XML_ParserCreate(nullptr);
   int done;

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.h

@@ -33,10 +33,11 @@ class ChapterHtmlSlimParser {
   int fontId;
   float lineCompression;
   bool extraParagraphSpacing;
-  int viewportWidth;
+  uint8_t paragraphAlignment;
-  int viewportHeight;
+  uint16_t viewportWidth;
+  uint16_t viewportHeight;
 
-  void startNewTextBlock(TextBlock::BLOCK_STYLE style);
+  void startNewTextBlock(TextBlock::Style style);
   void makePages();
   // XML callbacks
   static void XMLCALL startElement(void* userData, const XML_Char* name, const XML_Char** atts);
@@ -45,8 +46,9 @@ class ChapterHtmlSlimParser {
 
  public:
   explicit ChapterHtmlSlimParser(const std::string& filepath, GfxRenderer& renderer, const int fontId,
-                                 const float lineCompression, const bool extraParagraphSpacing, const int viewportWidth,
+                                 const float lineCompression, const bool extraParagraphSpacing,
-                                 const int viewportHeight,
+                                 const uint8_t paragraphAlignment, const uint16_t viewportWidth,
+                                 const uint16_t viewportHeight,
                                  const std::function<void(std::unique_ptr<Page>)>& completePageFn,
                                  const std::function<void(int)>& progressFn = nullptr)
       : filepath(filepath),
@@ -54,6 +56,7 @@ class ChapterHtmlSlimParser {
         fontId(fontId),
         lineCompression(lineCompression),
         extraParagraphSpacing(extraParagraphSpacing),
+        paragraphAlignment(paragraphAlignment),
         viewportWidth(viewportWidth),
         viewportHeight(viewportHeight),
         completePageFn(completePageFn),

lib/Epub/Epub/parsers/ContentOpfParser.cpp

@@ -161,14 +161,17 @@ void XMLCALL ContentOpfParser::startElement(void* userData, const XML_Char* name
     std::string itemId;
     std::string href;
     std::string mediaType;
+    std::string properties;
 
     for (int i = 0; atts[i]; i += 2) {
       if (strcmp(atts[i], "id") == 0) {
         itemId = atts[i + 1];
       } else if (strcmp(atts[i], "href") == 0) {
-        href = self->baseContentPath + atts[i + 1];
+        href = FsHelpers::normalisePath(self->baseContentPath + atts[i + 1]);
       } else if (strcmp(atts[i], "media-type") == 0) {
         mediaType = atts[i + 1];
+      } else if (strcmp(atts[i], "properties") == 0) {
+        properties = atts[i + 1];
       }
     }
 
@@ -188,6 +191,15 @@ void XMLCALL ContentOpfParser::startElement(void* userData, const XML_Char* name
                       href.c_str());
       }
     }
+
+    // EPUB 3: Check for nav document (properties contains "nav")
+    if (!properties.empty() && self->tocNavPath.empty()) {
+      // Properties is space-separated, check if "nav" is present as a word
+      if (properties == "nav" || properties.find("nav ") == 0 || properties.find(" nav") != std::string::npos) {
+        self->tocNavPath = href;
+        Serial.printf("[%lu] [COF] Found EPUB 3 nav document: %s\n", millis(), href.c_str());
+      }
+    }
     return;
   }
 
@@ -231,7 +243,7 @@ void XMLCALL ContentOpfParser::startElement(void* userData, const XML_Char* name
           break;
         }
       } else if (strcmp(atts[i], "href") == 0) {
-        textHref = self->baseContentPath + atts[i + 1];
+        textHref = FsHelpers::normalisePath(self->baseContentPath + atts[i + 1]);
       }
     }
     if ((type == "text" || (type == "start" && !self->textReferenceHref.empty())) && (textHref.length() > 0)) {

lib/Epub/Epub/parsers/ContentOpfParser.h

@@ -35,6 +35,7 @@ class ContentOpfParser final : public Print {
   std::string title;
   std::string author;
   std::string tocNcxPath;
+  std::string tocNavPath;  // EPUB 3 nav document path
   std::string coverItemHref;
   std::string textReferenceHref;
 

lib/Epub/Epub/parsers/TocNavParser.cpp

@@ -0,0 +1,185 @@
+#include "TocNavParser.h"
+
+#include <FsHelpers.h>
+#include <HardwareSerial.h>
+
+#include "../BookMetadataCache.h"
+
+bool TocNavParser::setup() {
+  parser = XML_ParserCreate(nullptr);
+  if (!parser) {
+    Serial.printf("[%lu] [NAV] Couldn't allocate memory for parser\n", millis());
+    return false;
+  }
+
+  XML_SetUserData(parser, this);
+  XML_SetElementHandler(parser, startElement, endElement);
+  XML_SetCharacterDataHandler(parser, characterData);
+  return true;
+}
+
+TocNavParser::~TocNavParser() {
+  if (parser) {
+    XML_StopParser(parser, XML_FALSE);
+    XML_SetElementHandler(parser, nullptr, nullptr);
+    XML_SetCharacterDataHandler(parser, nullptr);
+    XML_ParserFree(parser);
+    parser = nullptr;
+  }
+}
+
+size_t TocNavParser::write(const uint8_t data) { return write(&data, 1); }
+
+size_t TocNavParser::write(const uint8_t* buffer, const size_t size) {
+  if (!parser) return 0;
+
+  const uint8_t* currentBufferPos = buffer;
+  auto remainingInBuffer = size;
+
+  while (remainingInBuffer > 0) {
+    void* const buf = XML_GetBuffer(parser, 1024);
+    if (!buf) {
+      Serial.printf("[%lu] [NAV] Couldn't allocate memory for buffer\n", millis());
+      XML_StopParser(parser, XML_FALSE);
+      XML_SetElementHandler(parser, nullptr, nullptr);
+      XML_SetCharacterDataHandler(parser, nullptr);
+      XML_ParserFree(parser);
+      parser = nullptr;
+      return 0;
+    }
+
+    const auto toRead = remainingInBuffer < 1024 ? remainingInBuffer : 1024;
+    memcpy(buf, currentBufferPos, toRead);
+
+    if (XML_ParseBuffer(parser, static_cast<int>(toRead), remainingSize == toRead) == XML_STATUS_ERROR) {
+      Serial.printf("[%lu] [NAV] Parse error at line %lu: %s\n", millis(), XML_GetCurrentLineNumber(parser),
+                    XML_ErrorString(XML_GetErrorCode(parser)));
+      XML_StopParser(parser, XML_FALSE);
+      XML_SetElementHandler(parser, nullptr, nullptr);
+      XML_SetCharacterDataHandler(parser, nullptr);
+      XML_ParserFree(parser);
+      parser = nullptr;
+      return 0;
+    }
+
+    currentBufferPos += toRead;
+    remainingInBuffer -= toRead;
+    remainingSize -= toRead;
+  }
+  return size;
+}
+
+void XMLCALL TocNavParser::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
+  auto* self = static_cast<TocNavParser*>(userData);
+
+  // Track HTML structure loosely - we mainly care about finding <nav epub:type="toc">
+  if (strcmp(name, "html") == 0) {
+    self->state = IN_HTML;
+    return;
+  }
+
+  if (self->state == IN_HTML && strcmp(name, "body") == 0) {
+    self->state = IN_BODY;
+    return;
+  }
+
+  // Look for <nav epub:type="toc"> anywhere in body (or nested elements)
+  if (self->state >= IN_BODY && strcmp(name, "nav") == 0) {
+    for (int i = 0; atts[i]; i += 2) {
+      if ((strcmp(atts[i], "epub:type") == 0 || strcmp(atts[i], "type") == 0) && strcmp(atts[i + 1], "toc") == 0) {
+        self->state = IN_NAV_TOC;
+        Serial.printf("[%lu] [NAV] Found nav toc element\n", millis());
+        return;
+      }
+    }
+    return;
+  }
+
+  // Only process ol/li/a if we're inside the toc nav
+  if (self->state < IN_NAV_TOC) {
+    return;
+  }
+
+  if (strcmp(name, "ol") == 0) {
+    self->olDepth++;
+    self->state = IN_OL;
+    return;
+  }
+
+  if (self->state == IN_OL && strcmp(name, "li") == 0) {
+    self->state = IN_LI;
+    self->currentLabel.clear();
+    self->currentHref.clear();
+    return;
+  }
+
+  if (self->state == IN_LI && strcmp(name, "a") == 0) {
+    self->state = IN_ANCHOR;
+    // Get href attribute
+    for (int i = 0; atts[i]; i += 2) {
+      if (strcmp(atts[i], "href") == 0) {
+        self->currentHref = atts[i + 1];
+        break;
+      }
+    }
+    return;
+  }
+}
+
+void XMLCALL TocNavParser::characterData(void* userData, const XML_Char* s, const int len) {
+  auto* self = static_cast<TocNavParser*>(userData);
+
+  // Only collect text when inside an anchor within the TOC nav
+  if (self->state == IN_ANCHOR) {
+    self->currentLabel.append(s, len);
+  }
+}
+
+void XMLCALL TocNavParser::endElement(void* userData, const XML_Char* name) {
+  auto* self = static_cast<TocNavParser*>(userData);
+
+  if (strcmp(name, "a") == 0 && self->state == IN_ANCHOR) {
+    // Create TOC entry when closing anchor tag (we have all data now)
+    if (!self->currentLabel.empty() && !self->currentHref.empty()) {
+      std::string href = FsHelpers::normalisePath(self->baseContentPath + self->currentHref);
+      std::string anchor;
+
+      const size_t pos = href.find('#');
+      if (pos != std::string::npos) {
+        anchor = href.substr(pos + 1);
+        href = href.substr(0, pos);
+      }
+
+      if (self->cache) {
+        // olDepth gives us the nesting level (1-based from the outer ol)
+        self->cache->createTocEntry(self->currentLabel, href, anchor, self->olDepth);
+      }
+
+      self->currentLabel.clear();
+      self->currentHref.clear();
+    }
+    self->state = IN_LI;
+    return;
+  }
+
+  if (strcmp(name, "li") == 0 && (self->state == IN_LI || self->state == IN_OL)) {
+    self->state = IN_OL;
+    return;
+  }
+
+  if (strcmp(name, "ol") == 0 && self->state >= IN_NAV_TOC) {
+    self->olDepth--;
+    if (self->olDepth == 0) {
+      self->state = IN_NAV_TOC;
+    } else {
+      self->state = IN_LI;  // Back to parent li
+    }
+    return;
+  }
+
+  if (strcmp(name, "nav") == 0 && self->state >= IN_NAV_TOC) {
+    self->state = IN_BODY;
+    Serial.printf("[%lu] [NAV] Finished parsing nav toc\n", millis());
+    return;
+  }
+}

lib/Epub/Epub/parsers/TocNavParser.h

@@ -0,0 +1,47 @@
+#pragma once
+#include <Print.h>
+#include <expat.h>
+
+#include <string>
+
+class BookMetadataCache;
+
+// Parser for EPUB 3 nav.xhtml navigation documents
+// Parses HTML5 nav elements with epub:type="toc" to extract table of contents
+class TocNavParser final : public Print {
+  enum ParserState {
+    START,
+    IN_HTML,
+    IN_BODY,
+    IN_NAV_TOC,  // Inside <nav epub:type="toc">
+    IN_OL,       // Inside <ol>
+    IN_LI,       // Inside <li>
+    IN_ANCHOR,   // Inside <a>
+  };
+
+  const std::string& baseContentPath;
+  size_t remainingSize;
+  XML_Parser parser = nullptr;
+  ParserState state = START;
+  BookMetadataCache* cache;
+
+  // Track nesting depth for <ol> elements to determine TOC depth
+  uint8_t olDepth = 0;
+  // Current entry data being collected
+  std::string currentLabel;
+  std::string currentHref;
+
+  static void startElement(void* userData, const XML_Char* name, const XML_Char** atts);
+  static void characterData(void* userData, const XML_Char* s, int len);
+  static void endElement(void* userData, const XML_Char* name);
+
+ public:
+  explicit TocNavParser(const std::string& baseContentPath, const size_t xmlSize, BookMetadataCache* cache)
+      : baseContentPath(baseContentPath), remainingSize(xmlSize), cache(cache) {}
+  ~TocNavParser() override;
+
+  bool setup();
+
+  size_t write(uint8_t) override;
+  size_t write(const uint8_t* buffer, size_t size) override;
+};

lib/Epub/Epub/parsers/TocNcxParser.cpp

@@ -1,5 +1,6 @@
 #include "TocNcxParser.h"
 
+#include <FsHelpers.h>
 #include <HardwareSerial.h>
 
 #include "../BookMetadataCache.h"
@@ -159,7 +160,7 @@ void XMLCALL TocNcxParser::endElement(void* userData, const XML_Char* name) {
     // This is the safest place to push the data, assuming <navLabel> always comes before <content>.
     // NCX spec says navLabel comes before content.
     if (!self->currentLabel.empty() && !self->currentSrc.empty()) {
-      std::string href = self->baseContentPath + self->currentSrc;
+      std::string href = FsHelpers::normalisePath(self->baseContentPath + self->currentSrc);
       std::string anchor;
 
       const size_t pos = href.find('#');

lib/GfxRenderer/Bitmap.cpp

@@ -8,119 +8,15 @@
 // ============================================================================
 // Note: For cover images, dithering is done in JpegToBmpConverter.cpp
 // This file handles BMP reading - use simple quantization to avoid double-dithering
-constexpr bool USE_FLOYD_STEINBERG = false;  // Disabled - dithering done at JPEG conversion
+constexpr bool USE_ATKINSON = true;  // Use Atkinson dithering instead of Floyd-Steinberg
-constexpr bool USE_NOISE_DITHERING = false;  // Hash-based noise dithering
-// Brightness adjustments:
-constexpr bool USE_BRIGHTNESS = false;    // true: apply brightness/gamma adjustments
-constexpr int BRIGHTNESS_BOOST = 20;      // Brightness offset (0-50), only if USE_BRIGHTNESS=true
-constexpr bool GAMMA_CORRECTION = false;  // Gamma curve, only if USE_BRIGHTNESS=true
 // ============================================================================
 
-// Integer approximation of gamma correction (brightens midtones)
-static inline int applyGamma(int gray) {
-  if (!GAMMA_CORRECTION) return gray;
-  const int product = gray * 255;
-  int x = gray;
-  if (x > 0) {
-    x = (x + product / x) >> 1;
-    x = (x + product / x) >> 1;
-  }
-  return x > 255 ? 255 : x;
-}
-
-// Simple quantization without dithering - just divide into 4 levels
-static inline uint8_t quantizeSimple(int gray) {
-  if (USE_BRIGHTNESS) {
-    gray += BRIGHTNESS_BOOST;
-    if (gray > 255) gray = 255;
-    gray = applyGamma(gray);
-  }
-  return static_cast<uint8_t>(gray >> 6);
-}
-
-// Hash-based noise dithering - survives downsampling without moiré artifacts
-static inline uint8_t quantizeNoise(int gray, int x, int y) {
-  if (USE_BRIGHTNESS) {
-    gray += BRIGHTNESS_BOOST;
-    if (gray > 255) gray = 255;
-    gray = applyGamma(gray);
-  }
-
-  uint32_t hash = static_cast<uint32_t>(x) * 374761393u + static_cast<uint32_t>(y) * 668265263u;
-  hash = (hash ^ (hash >> 13)) * 1274126177u;
-  const int threshold = static_cast<int>(hash >> 24);
-
-  const int scaled = gray * 3;
-  if (scaled < 255) {
-    return (scaled + threshold >= 255) ? 1 : 0;
-  } else if (scaled < 510) {
-    return ((scaled - 255) + threshold >= 255) ? 2 : 1;
-  } else {
-    return ((scaled - 510) + threshold >= 255) ? 3 : 2;
-  }
-}
-
-// Main quantization function
-static inline uint8_t quantize(int gray, int x, int y) {
-  if (USE_NOISE_DITHERING) {
-    return quantizeNoise(gray, x, y);
-  } else {
-    return quantizeSimple(gray);
-  }
-}
-
-// Floyd-Steinberg quantization with error diffusion and serpentine scanning
-// Returns 2-bit value (0-3) and updates error buffers
-static inline uint8_t quantizeFloydSteinberg(int gray, int x, int width, int16_t* errorCurRow, int16_t* errorNextRow,
-                                             bool reverseDir) {
-  // Add accumulated error to this pixel
-  int adjusted = gray + errorCurRow[x + 1];
-
-  // Clamp to valid range
-  if (adjusted < 0) adjusted = 0;
-  if (adjusted > 255) adjusted = 255;
-
-  // Quantize to 4 levels (0, 85, 170, 255)
-  uint8_t quantized;
-  int quantizedValue;
-  if (adjusted < 43) {
-    quantized = 0;
-    quantizedValue = 0;
-  } else if (adjusted < 128) {
-    quantized = 1;
-    quantizedValue = 85;
-  } else if (adjusted < 213) {
-    quantized = 2;
-    quantizedValue = 170;
-  } else {
-    quantized = 3;
-    quantizedValue = 255;
-  }
-
-  // Calculate error
-  int error = adjusted - quantizedValue;
-
-  // Distribute error to neighbors (serpentine: direction-aware)
-  if (!reverseDir) {
-    // Left to right
-    errorCurRow[x + 2] += (error * 7) >> 4;   // Right: 7/16
-    errorNextRow[x] += (error * 3) >> 4;      // Bottom-left: 3/16
-    errorNextRow[x + 1] += (error * 5) >> 4;  // Bottom: 5/16
-    errorNextRow[x + 2] += (error) >> 4;      // Bottom-right: 1/16
-  } else {
-    // Right to left (mirrored)
-    errorCurRow[x] += (error * 7) >> 4;       // Left: 7/16
-    errorNextRow[x + 2] += (error * 3) >> 4;  // Bottom-right: 3/16
-    errorNextRow[x + 1] += (error * 5) >> 4;  // Bottom: 5/16
-    errorNextRow[x] += (error) >> 4;          // Bottom-left: 1/16
-  }
-
-  return quantized;
-}
-
 Bitmap::~Bitmap() {
   delete[] errorCurRow;
   delete[] errorNextRow;
+
+  delete atkinsonDitherer;
+  delete fsDitherer;
 }
 
 uint16_t Bitmap::readLE16(FsFile& f) {
@@ -244,40 +140,25 @@ BmpReaderError Bitmap::parseHeaders() {
     return BmpReaderError::SeekPixelDataFailed;
   }
 
-  // Allocate Floyd-Steinberg error buffers if enabled
+  // Create ditherer if enabled (only for 2-bit output)
-  if (USE_FLOYD_STEINBERG) {
+  // Use OUTPUT dimensions for dithering (after prescaling)
-    delete[] errorCurRow;
+  if (bpp > 2 && dithering) {
-    delete[] errorNextRow;
+    if (USE_ATKINSON) {
-    errorCurRow = new int16_t[width + 2]();  // +2 for boundary handling
+      atkinsonDitherer = new AtkinsonDitherer(width);
-    errorNextRow = new int16_t[width + 2]();
+    } else {
-    lastRowY = -1;
+      fsDitherer = new FloydSteinbergDitherer(width);
+    }
   }
 
   return BmpReaderError::Ok;
 }
 
 // packed 2bpp output, 0 = black, 1 = dark gray, 2 = light gray, 3 = white
-BmpReaderError Bitmap::readRow(uint8_t* data, uint8_t* rowBuffer, int rowY) const {
+BmpReaderError Bitmap::readNextRow(uint8_t* data, uint8_t* rowBuffer) const {
   // Note: rowBuffer should be pre-allocated by the caller to size 'rowBytes'
   if (file.read(rowBuffer, rowBytes) != rowBytes) return BmpReaderError::ShortReadRow;
 
-  // Handle Floyd-Steinberg error buffer progression
+  prevRowY += 1;
-  const bool useFS = USE_FLOYD_STEINBERG && errorCurRow && errorNextRow;
-  if (useFS) {
-    // Check if we need to advance to next row (or reset if jumping)
-    if (rowY != lastRowY + 1 && rowY != 0) {
-      // Non-sequential row access - reset error buffers
-      memset(errorCurRow, 0, (width + 2) * sizeof(int16_t));
-      memset(errorNextRow, 0, (width + 2) * sizeof(int16_t));
-    } else if (rowY > 0) {
-      // Sequential access - swap buffers
-      int16_t* temp = errorCurRow;
-      errorCurRow = errorNextRow;
-      errorNextRow = temp;
-      memset(errorNextRow, 0, (width + 2) * sizeof(int16_t));
-    }
-    lastRowY = rowY;
-  }
 
   uint8_t* outPtr = data;
   uint8_t currentOutByte = 0;
@@ -287,12 +168,18 @@ BmpReaderError Bitmap::readRow(uint8_t* data, uint8_t* rowBuffer, int rowY) cons
   // Helper lambda to pack 2bpp color into the output stream
   auto packPixel = [&](const uint8_t lum) {
     uint8_t color;
-    if (useFS) {
+    if (atkinsonDitherer) {
-      // Floyd-Steinberg error diffusion
+      color = atkinsonDitherer->processPixel(adjustPixel(lum), currentX);
-      color = quantizeFloydSteinberg(lum, currentX, width, errorCurRow, errorNextRow, false);
+    } else if (fsDitherer) {
+      color = fsDitherer->processPixel(adjustPixel(lum), currentX);
     } else {
+      if (bpp > 2) {
         // Simple quantization or noise dithering
-      color = quantize(lum, currentX, rowY);
+        color = quantize(adjustPixel(lum), currentX, prevRowY);
+      } else {
+        // do not quantize 2bpp image
+        color = static_cast<uint8_t>(lum >> 6);
+      }
     }
     currentOutByte |= (color << bitShift);
     if (bitShift == 0) {
@@ -350,6 +237,11 @@ BmpReaderError Bitmap::readRow(uint8_t* data, uint8_t* rowBuffer, int rowY) cons
       return BmpReaderError::UnsupportedBpp;
   }
 
+  if (atkinsonDitherer)
+    atkinsonDitherer->nextRow();
+  else if (fsDitherer)
+    fsDitherer->nextRow();
+
   // Flush remaining bits if width is not a multiple of 4
   if (bitShift != 6) *outPtr = currentOutByte;
 
@@ -361,12 +253,9 @@ BmpReaderError Bitmap::rewindToData() const {
     return BmpReaderError::SeekPixelDataFailed;
   }
 
-  // Reset Floyd-Steinberg error buffers when rewinding
+  // Reset dithering when rewinding
-  if (USE_FLOYD_STEINBERG && errorCurRow && errorNextRow) {
+  if (fsDitherer) fsDitherer->reset();
-    memset(errorCurRow, 0, (width + 2) * sizeof(int16_t));
+  if (atkinsonDitherer) atkinsonDitherer->reset();
-    memset(errorNextRow, 0, (width + 2) * sizeof(int16_t));
-    lastRowY = -1;
-  }
 
   return BmpReaderError::Ok;
 }

lib/GfxRenderer/Bitmap.h

@@ -2,6 +2,10 @@
 
 #include <SdFat.h>
 
+#include <cstdint>
+
+#include "BitmapHelpers.h"
+
 enum class BmpReaderError : uint8_t {
   Ok = 0,
   FileInvalid,
@@ -28,10 +32,10 @@ class Bitmap {
  public:
   static const char* errorToString(BmpReaderError err);
 
-  explicit Bitmap(FsFile& file) : file(file) {}
+  explicit Bitmap(FsFile& file, bool dithering = false) : file(file), dithering(dithering) {}
   ~Bitmap();
   BmpReaderError parseHeaders();
-  BmpReaderError readRow(uint8_t* data, uint8_t* rowBuffer, int rowY) const;
+  BmpReaderError readNextRow(uint8_t* data, uint8_t* rowBuffer) const;
   BmpReaderError rewindToData() const;
   int getWidth() const { return width; }
   int getHeight() const { return height; }
@@ -44,6 +48,7 @@ class Bitmap {
   static uint32_t readLE32(FsFile& f);
 
   FsFile& file;
+  bool dithering = false;
   int width = 0;
   int height = 0;
   bool topDown = false;
@@ -55,5 +60,8 @@ class Bitmap {
   // Floyd-Steinberg dithering state (mutable for const methods)
   mutable int16_t* errorCurRow = nullptr;
   mutable int16_t* errorNextRow = nullptr;
-  mutable int lastRowY = -1;  // Track row progression for error propagation
+  mutable int prevRowY = -1;  // Track row progression for error propagation
+
+  mutable AtkinsonDitherer* atkinsonDitherer = nullptr;
+  mutable FloydSteinbergDitherer* fsDitherer = nullptr;
 };

lib/GfxRenderer/BitmapHelpers.cpp

@@ -0,0 +1,90 @@
+#include "BitmapHelpers.h"
+
+#include <cstdint>
+
+// Brightness/Contrast adjustments:
+constexpr bool USE_BRIGHTNESS = false;       // true: apply brightness/gamma adjustments
+constexpr int BRIGHTNESS_BOOST = 10;         // Brightness offset (0-50)
+constexpr bool GAMMA_CORRECTION = false;     // Gamma curve (brightens midtones)
+constexpr float CONTRAST_FACTOR = 1.15f;     // Contrast multiplier (1.0 = no change, >1 = more contrast)
+constexpr bool USE_NOISE_DITHERING = false;  // Hash-based noise dithering
+
+// Integer approximation of gamma correction (brightens midtones)
+// Uses a simple curve: out = 255 * sqrt(in/255) ≈ sqrt(in * 255)
+static inline int applyGamma(int gray) {
+  if (!GAMMA_CORRECTION) return gray;
+  // Fast integer square root approximation for gamma ~0.5 (brightening)
+  // This brightens dark/mid tones while preserving highlights
+  const int product = gray * 255;
+  // Newton-Raphson integer sqrt (2 iterations for good accuracy)
+  int x = gray;
+  if (x > 0) {
+    x = (x + product / x) >> 1;
+    x = (x + product / x) >> 1;
+  }
+  return x > 255 ? 255 : x;
+}
+
+// Apply contrast adjustment around midpoint (128)
+// factor > 1.0 increases contrast, < 1.0 decreases
+static inline int applyContrast(int gray) {
+  // Integer-based contrast: (gray - 128) * factor + 128
+  // Using fixed-point: factor 1.15 ≈ 115/100
+  constexpr int factorNum = static_cast<int>(CONTRAST_FACTOR * 100);
+  int adjusted = ((gray - 128) * factorNum) / 100 + 128;
+  if (adjusted < 0) adjusted = 0;
+  if (adjusted > 255) adjusted = 255;
+  return adjusted;
+}
+// Combined brightness/contrast/gamma adjustment
+int adjustPixel(int gray) {
+  if (!USE_BRIGHTNESS) return gray;
+
+  // Order: contrast first, then brightness, then gamma
+  gray = applyContrast(gray);
+  gray += BRIGHTNESS_BOOST;
+  if (gray > 255) gray = 255;
+  if (gray < 0) gray = 0;
+  gray = applyGamma(gray);
+
+  return gray;
+}
+// Simple quantization without dithering - divide into 4 levels
+// The thresholds are fine-tuned to the X4 display
+uint8_t quantizeSimple(int gray) {
+  if (gray < 45) {
+    return 0;
+  } else if (gray < 70) {
+    return 1;
+  } else if (gray < 140) {
+    return 2;
+  } else {
+    return 3;
+  }
+}
+
+// Hash-based noise dithering - survives downsampling without moiré artifacts
+// Uses integer hash to generate pseudo-random threshold per pixel
+static inline uint8_t quantizeNoise(int gray, int x, int y) {
+  uint32_t hash = static_cast<uint32_t>(x) * 374761393u + static_cast<uint32_t>(y) * 668265263u;
+  hash = (hash ^ (hash >> 13)) * 1274126177u;
+  const int threshold = static_cast<int>(hash >> 24);
+
+  const int scaled = gray * 3;
+  if (scaled < 255) {
+    return (scaled + threshold >= 255) ? 1 : 0;
+  } else if (scaled < 510) {
+    return ((scaled - 255) + threshold >= 255) ? 2 : 1;
+  } else {
+    return ((scaled - 510) + threshold >= 255) ? 3 : 2;
+  }
+}
+
+// Main quantization function - selects between methods based on config
+uint8_t quantize(int gray, int x, int y) {
+  if (USE_NOISE_DITHERING) {
+    return quantizeNoise(gray, x, y);
+  } else {
+    return quantizeSimple(gray);
+  }
+}

lib/GfxRenderer/BitmapHelpers.h

@@ -0,0 +1,233 @@
+#pragma once
+
+#include <cstring>
+
+// Helper functions
+uint8_t quantize(int gray, int x, int y);
+uint8_t quantizeSimple(int gray);
+int adjustPixel(int gray);
+
+// Atkinson dithering - distributes only 6/8 (75%) of error for cleaner results
+// Error distribution pattern:
+//     X  1/8 1/8
+// 1/8 1/8 1/8
+//     1/8
+// Less error buildup = fewer artifacts than Floyd-Steinberg
+class AtkinsonDitherer {
+ public:
+  explicit AtkinsonDitherer(int width) : width(width) {
+    errorRow0 = new int16_t[width + 4]();  // Current row
+    errorRow1 = new int16_t[width + 4]();  // Next row
+    errorRow2 = new int16_t[width + 4]();  // Row after next
+  }
+
+  ~AtkinsonDitherer() {
+    delete[] errorRow0;
+    delete[] errorRow1;
+    delete[] errorRow2;
+  }
+  // **1. EXPLICITLY DELETE THE COPY CONSTRUCTOR**
+  AtkinsonDitherer(const AtkinsonDitherer& other) = delete;
+
+  // **2. EXPLICITLY DELETE THE COPY ASSIGNMENT OPERATOR**
+  AtkinsonDitherer& operator=(const AtkinsonDitherer& other) = delete;
+
+  uint8_t processPixel(int gray, int x) {
+    // Add accumulated error
+    int adjusted = gray + errorRow0[x + 2];
+    if (adjusted < 0) adjusted = 0;
+    if (adjusted > 255) adjusted = 255;
+
+    // Quantize to 4 levels
+    uint8_t quantized;
+    int quantizedValue;
+    if (false) {  // original thresholds
+      if (adjusted < 43) {
+        quantized = 0;
+        quantizedValue = 0;
+      } else if (adjusted < 128) {
+        quantized = 1;
+        quantizedValue = 85;
+      } else if (adjusted < 213) {
+        quantized = 2;
+        quantizedValue = 170;
+      } else {
+        quantized = 3;
+        quantizedValue = 255;
+      }
+    } else {  // fine-tuned to X4 eink display
+      if (adjusted < 30) {
+        quantized = 0;
+        quantizedValue = 15;
+      } else if (adjusted < 50) {
+        quantized = 1;
+        quantizedValue = 30;
+      } else if (adjusted < 140) {
+        quantized = 2;
+        quantizedValue = 80;
+      } else {
+        quantized = 3;
+        quantizedValue = 210;
+      }
+    }
+
+    // Calculate error (only distribute 6/8 = 75%)
+    int error = (adjusted - quantizedValue) >> 3;  // error/8
+
+    // Distribute 1/8 to each of 6 neighbors
+    errorRow0[x + 3] += error;  // Right
+    errorRow0[x + 4] += error;  // Right+1
+    errorRow1[x + 1] += error;  // Bottom-left
+    errorRow1[x + 2] += error;  // Bottom
+    errorRow1[x + 3] += error;  // Bottom-right
+    errorRow2[x + 2] += error;  // Two rows down
+
+    return quantized;
+  }
+
+  void nextRow() {
+    int16_t* temp = errorRow0;
+    errorRow0 = errorRow1;
+    errorRow1 = errorRow2;
+    errorRow2 = temp;
+    memset(errorRow2, 0, (width + 4) * sizeof(int16_t));
+  }
+
+  void reset() {
+    memset(errorRow0, 0, (width + 4) * sizeof(int16_t));
+    memset(errorRow1, 0, (width + 4) * sizeof(int16_t));
+    memset(errorRow2, 0, (width + 4) * sizeof(int16_t));
+  }
+
+ private:
+  int width;
+  int16_t* errorRow0;
+  int16_t* errorRow1;
+  int16_t* errorRow2;
+};
+
+// Floyd-Steinberg error diffusion dithering with serpentine scanning
+// Serpentine scanning alternates direction each row to reduce "worm" artifacts
+// Error distribution pattern (left-to-right):
+//       X   7/16
+// 3/16 5/16 1/16
+// Error distribution pattern (right-to-left, mirrored):
+// 1/16 5/16 3/16
+//      7/16  X
+class FloydSteinbergDitherer {
+ public:
+  explicit FloydSteinbergDitherer(int width) : width(width), rowCount(0) {
+    errorCurRow = new int16_t[width + 2]();  // +2 for boundary handling
+    errorNextRow = new int16_t[width + 2]();
+  }
+
+  ~FloydSteinbergDitherer() {
+    delete[] errorCurRow;
+    delete[] errorNextRow;
+  }
+
+  // **1. EXPLICITLY DELETE THE COPY CONSTRUCTOR**
+  FloydSteinbergDitherer(const FloydSteinbergDitherer& other) = delete;
+
+  // **2. EXPLICITLY DELETE THE COPY ASSIGNMENT OPERATOR**
+  FloydSteinbergDitherer& operator=(const FloydSteinbergDitherer& other) = delete;
+
+  // Process a single pixel and return quantized 2-bit value
+  // x is the logical x position (0 to width-1), direction handled internally
+  uint8_t processPixel(int gray, int x) {
+    // Add accumulated error to this pixel
+    int adjusted = gray + errorCurRow[x + 1];
+
+    // Clamp to valid range
+    if (adjusted < 0) adjusted = 0;
+    if (adjusted > 255) adjusted = 255;
+
+    // Quantize to 4 levels (0, 85, 170, 255)
+    uint8_t quantized;
+    int quantizedValue;
+    if (false) {  // original thresholds
+      if (adjusted < 43) {
+        quantized = 0;
+        quantizedValue = 0;
+      } else if (adjusted < 128) {
+        quantized = 1;
+        quantizedValue = 85;
+      } else if (adjusted < 213) {
+        quantized = 2;
+        quantizedValue = 170;
+      } else {
+        quantized = 3;
+        quantizedValue = 255;
+      }
+    } else {  // fine-tuned to X4 eink display
+      if (adjusted < 30) {
+        quantized = 0;
+        quantizedValue = 15;
+      } else if (adjusted < 50) {
+        quantized = 1;
+        quantizedValue = 30;
+      } else if (adjusted < 140) {
+        quantized = 2;
+        quantizedValue = 80;
+      } else {
+        quantized = 3;
+        quantizedValue = 210;
+      }
+    }
+
+    // Calculate error
+    int error = adjusted - quantizedValue;
+
+    // Distribute error to neighbors (serpentine: direction-aware)
+    if (!isReverseRow()) {
+      // Left to right: standard distribution
+      // Right: 7/16
+      errorCurRow[x + 2] += (error * 7) >> 4;
+      // Bottom-left: 3/16
+      errorNextRow[x] += (error * 3) >> 4;
+      // Bottom: 5/16
+      errorNextRow[x + 1] += (error * 5) >> 4;
+      // Bottom-right: 1/16
+      errorNextRow[x + 2] += (error) >> 4;
+    } else {
+      // Right to left: mirrored distribution
+      // Left: 7/16
+      errorCurRow[x] += (error * 7) >> 4;
+      // Bottom-right: 3/16
+      errorNextRow[x + 2] += (error * 3) >> 4;
+      // Bottom: 5/16
+      errorNextRow[x + 1] += (error * 5) >> 4;
+      // Bottom-left: 1/16
+      errorNextRow[x] += (error) >> 4;
+    }
+
+    return quantized;
+  }
+
+  // Call at the end of each row to swap buffers
+  void nextRow() {
+    // Swap buffers
+    int16_t* temp = errorCurRow;
+    errorCurRow = errorNextRow;
+    errorNextRow = temp;
+    // Clear the next row buffer
+    memset(errorNextRow, 0, (width + 2) * sizeof(int16_t));
+    rowCount++;
+  }
+
+  // Check if current row should be processed in reverse
+  bool isReverseRow() const { return (rowCount & 1) != 0; }
+
+  // Reset for a new image or MCU block
+  void reset() {
+    memset(errorCurRow, 0, (width + 2) * sizeof(int16_t));
+    memset(errorNextRow, 0, (width + 2) * sizeof(int16_t));
+    rowCount = 0;
+  }
+
+ private:
+  int width;
+  int rowCount;
+  int16_t* errorCurRow;
+  int16_t* errorNextRow;
+};

lib/GfxRenderer/GfxRenderer.cpp

@@ -66,7 +66,7 @@ void GfxRenderer::drawPixel(const int x, const int y, const bool state) const {
   }
 }
 
-int GfxRenderer::getTextWidth(const int fontId, const char* text, const EpdFontStyle style) const {
+int GfxRenderer::getTextWidth(const int fontId, const char* text, const EpdFontFamily::Style style) const {
   if (fontMap.count(fontId) == 0) {
     Serial.printf("[%lu] [GFX] Font %d not found\n", millis(), fontId);
     return 0;
@@ -78,13 +78,13 @@ int GfxRenderer::getTextWidth(const int fontId, const char* text, const EpdFontS
 }
 
 void GfxRenderer::drawCenteredText(const int fontId, const int y, const char* text, const bool black,
-                                   const EpdFontStyle style) const {
+                                   const EpdFontFamily::Style style) const {
   const int x = (getScreenWidth() - getTextWidth(fontId, text, style)) / 2;
   drawText(fontId, x, y, text, black, style);
 }
 
 void GfxRenderer::drawText(const int fontId, const int x, const int y, const char* text, const bool black,
-                           const EpdFontStyle style) const {
+                           const EpdFontFamily::Style style) const {
   const int yPos = y + getFontAscenderSize(fontId);
   int xpos = x;
 
@@ -152,18 +152,24 @@ void GfxRenderer::drawImage(const uint8_t bitmap[], const int x, const int y, co
   einkDisplay.drawImage(bitmap, rotatedX, rotatedY, width, height);
 }
 
-void GfxRenderer::drawBitmap(const Bitmap& bitmap, const int x, const int y, const int maxWidth,
+void GfxRenderer::drawBitmap(const Bitmap& bitmap, const int x, const int y, const int maxWidth, const int maxHeight,
-                             const int maxHeight) const {
+                             const float cropX, const float cropY) const {
   float scale = 1.0f;
   bool isScaled = false;
-  if (maxWidth > 0 && bitmap.getWidth() > maxWidth) {
+  int cropPixX = std::floor(bitmap.getWidth() * cropX / 2.0f);
-    scale = static_cast<float>(maxWidth) / static_cast<float>(bitmap.getWidth());
+  int cropPixY = std::floor(bitmap.getHeight() * cropY / 2.0f);
+  Serial.printf("[%lu] [GFX] Cropping %dx%d by %dx%d pix, is %s\n", millis(), bitmap.getWidth(), bitmap.getHeight(),
+                cropPixX, cropPixY, bitmap.isTopDown() ? "top-down" : "bottom-up");
+
+  if (maxWidth > 0 && (1.0f - cropX) * bitmap.getWidth() > maxWidth) {
+    scale = static_cast<float>(maxWidth) / static_cast<float>((1.0f - cropX) * bitmap.getWidth());
     isScaled = true;
   }
-  if (maxHeight > 0 && bitmap.getHeight() > maxHeight) {
+  if (maxHeight > 0 && (1.0f - cropY) * bitmap.getHeight() > maxHeight) {
-    scale = std::min(scale, static_cast<float>(maxHeight) / static_cast<float>(bitmap.getHeight()));
+    scale = std::min(scale, static_cast<float>(maxHeight) / static_cast<float>((1.0f - cropY) * bitmap.getHeight()));
     isScaled = true;
   }
+  Serial.printf("[%lu] [GFX] Scaling by %f - %s\n", millis(), scale, isScaled ? "scaled" : "not scaled");
 
   // Calculate output row size (2 bits per pixel, packed into bytes)
   // IMPORTANT: Use int, not uint8_t, to avoid overflow for images > 1020 pixels wide
@@ -178,29 +184,36 @@ void GfxRenderer::drawBitmap(const Bitmap& bitmap, const int x, const int y, con
     return;
   }
 
-  for (int bmpY = 0; bmpY < bitmap.getHeight(); bmpY++) {
+  for (int bmpY = 0; bmpY < (bitmap.getHeight() - cropPixY); bmpY++) {
     // The BMP's (0, 0) is the bottom-left corner (if the height is positive, top-left if negative).
     // Screen's (0, 0) is the top-left corner.
-    int screenY = y + (bitmap.isTopDown() ? bmpY : bitmap.getHeight() - 1 - bmpY);
+    int screenY = -cropPixY + (bitmap.isTopDown() ? bmpY : bitmap.getHeight() - 1 - bmpY);
     if (isScaled) {
       screenY = std::floor(screenY * scale);
     }
+    screenY += y;  // the offset should not be scaled
     if (screenY >= getScreenHeight()) {
       break;
     }
 
-    if (bitmap.readRow(outputRow, rowBytes, bmpY) != BmpReaderError::Ok) {
+    if (bitmap.readNextRow(outputRow, rowBytes) != BmpReaderError::Ok) {
       Serial.printf("[%lu] [GFX] Failed to read row %d from bitmap\n", millis(), bmpY);
       free(outputRow);
       free(rowBytes);
       return;
     }
 
-    for (int bmpX = 0; bmpX < bitmap.getWidth(); bmpX++) {
+    if (bmpY < cropPixY) {
-      int screenX = x + bmpX;
+      // Skip the row if it's outside the crop area
+      continue;
+    }
+
+    for (int bmpX = cropPixX; bmpX < bitmap.getWidth() - cropPixX; bmpX++) {
+      int screenX = bmpX - cropPixX;
       if (isScaled) {
         screenX = std::floor(screenX * scale);
       }
+      screenX += x;  // the offset should not be scaled
       if (screenX >= getScreenWidth()) {
         break;
       }
@@ -238,6 +251,17 @@ void GfxRenderer::displayBuffer(const EInkDisplay::RefreshMode refreshMode) cons
   einkDisplay.displayBuffer(refreshMode);
 }
 
+std::string GfxRenderer::truncatedText(const int fontId, const char* text, const int maxWidth,
+                                       const EpdFontFamily::Style style) const {
+  std::string item = text;
+  int itemWidth = getTextWidth(fontId, item.c_str(), style);
+  while (itemWidth > maxWidth && item.length() > 8) {
+    item.replace(item.length() - 5, 5, "...");
+    itemWidth = getTextWidth(fontId, item.c_str(), style);
+  }
+  return item;
+}
+
 // Note: Internal driver treats screen in command orientation; this library exposes a logical orientation
 int GfxRenderer::getScreenWidth() const {
   switch (orientation) {
@@ -273,7 +297,7 @@ int GfxRenderer::getSpaceWidth(const int fontId) const {
     return 0;
   }
 
-  return fontMap.at(fontId).getGlyph(' ', REGULAR)->advanceX;
+  return fontMap.at(fontId).getGlyph(' ', EpdFontFamily::REGULAR)->advanceX;
 }
 
 int GfxRenderer::getFontAscenderSize(const int fontId) const {
@@ -282,7 +306,7 @@ int GfxRenderer::getFontAscenderSize(const int fontId) const {
     return 0;
   }
 
-  return fontMap.at(fontId).getData(REGULAR)->ascender;
+  return fontMap.at(fontId).getData(EpdFontFamily::REGULAR)->ascender;
 }
 
 int GfxRenderer::getLineHeight(const int fontId) const {
@@ -291,7 +315,7 @@ int GfxRenderer::getLineHeight(const int fontId) const {
     return 0;
   }
 
-  return fontMap.at(fontId).getData(REGULAR)->advanceY;
+  return fontMap.at(fontId).getData(EpdFontFamily::REGULAR)->advanceY;
 }
 
 void GfxRenderer::drawButtonHints(const int fontId, const char* btn1, const char* btn2, const char* btn3,
@@ -316,6 +340,148 @@ void GfxRenderer::drawButtonHints(const int fontId, const char* btn1, const char
   }
 }
 
+void GfxRenderer::drawSideButtonHints(const int fontId, const char* topBtn, const char* bottomBtn) const {
+  const int screenWidth = getScreenWidth();
+  constexpr int buttonWidth = 40;   // Width on screen (height when rotated)
+  constexpr int buttonHeight = 80;  // Height on screen (width when rotated)
+  constexpr int buttonX = 5;        // Distance from right edge
+  // Position for the button group - buttons share a border so they're adjacent
+  constexpr int topButtonY = 345;  // Top button position
+
+  const char* labels[] = {topBtn, bottomBtn};
+
+  // Draw the shared border for both buttons as one unit
+  const int x = screenWidth - buttonX - buttonWidth;
+
+  // Draw top button outline (3 sides, bottom open)
+  if (topBtn != nullptr && topBtn[0] != '\0') {
+    drawLine(x, topButtonY, x + buttonWidth - 1, topButtonY);                                       // Top
+    drawLine(x, topButtonY, x, topButtonY + buttonHeight - 1);                                      // Left
+    drawLine(x + buttonWidth - 1, topButtonY, x + buttonWidth - 1, topButtonY + buttonHeight - 1);  // Right
+  }
+
+  // Draw shared middle border
+  if ((topBtn != nullptr && topBtn[0] != '\0') || (bottomBtn != nullptr && bottomBtn[0] != '\0')) {
+    drawLine(x, topButtonY + buttonHeight, x + buttonWidth - 1, topButtonY + buttonHeight);  // Shared border
+  }
+
+  // Draw bottom button outline (3 sides, top is shared)
+  if (bottomBtn != nullptr && bottomBtn[0] != '\0') {
+    drawLine(x, topButtonY + buttonHeight, x, topButtonY + 2 * buttonHeight - 1);  // Left
+    drawLine(x + buttonWidth - 1, topButtonY + buttonHeight, x + buttonWidth - 1,
+             topButtonY + 2 * buttonHeight - 1);                                                             // Right
+    drawLine(x, topButtonY + 2 * buttonHeight - 1, x + buttonWidth - 1, topButtonY + 2 * buttonHeight - 1);  // Bottom
+  }
+
+  // Draw text for each button
+  for (int i = 0; i < 2; i++) {
+    if (labels[i] != nullptr && labels[i][0] != '\0') {
+      const int y = topButtonY + i * buttonHeight;
+
+      // Draw rotated text centered in the button
+      const int textWidth = getTextWidth(fontId, labels[i]);
+      const int textHeight = getTextHeight(fontId);
+
+      // Center the rotated text in the button
+      const int textX = x + (buttonWidth - textHeight) / 2;
+      const int textY = y + (buttonHeight + textWidth) / 2;
+
+      drawTextRotated90CW(fontId, textX, textY, labels[i]);
+    }
+  }
+}
+
+int GfxRenderer::getTextHeight(const int fontId) const {
+  if (fontMap.count(fontId) == 0) {
+    Serial.printf("[%lu] [GFX] Font %d not found\n", millis(), fontId);
+    return 0;
+  }
+  return fontMap.at(fontId).getData(EpdFontFamily::REGULAR)->ascender;
+}
+
+void GfxRenderer::drawTextRotated90CW(const int fontId, const int x, const int y, const char* text, const bool black,
+                                      const EpdFontFamily::Style style) const {
+  // Cannot draw a NULL / empty string
+  if (text == nullptr || *text == '\0') {
+    return;
+  }
+
+  if (fontMap.count(fontId) == 0) {
+    Serial.printf("[%lu] [GFX] Font %d not found\n", millis(), fontId);
+    return;
+  }
+  const auto font = fontMap.at(fontId);
+
+  // No printable characters
+  if (!font.hasPrintableChars(text, style)) {
+    return;
+  }
+
+  // For 90° clockwise rotation:
+  // Original (glyphX, glyphY) -> Rotated (glyphY, -glyphX)
+  // Text reads from bottom to top
+
+  int yPos = y;  // Current Y position (decreases as we draw characters)
+
+  uint32_t cp;
+  while ((cp = utf8NextCodepoint(reinterpret_cast<const uint8_t**>(&text)))) {
+    const EpdGlyph* glyph = font.getGlyph(cp, style);
+    if (!glyph) {
+      glyph = font.getGlyph('?', style);
+    }
+    if (!glyph) {
+      continue;
+    }
+
+    const int is2Bit = font.getData(style)->is2Bit;
+    const uint32_t offset = glyph->dataOffset;
+    const uint8_t width = glyph->width;
+    const uint8_t height = glyph->height;
+    const int left = glyph->left;
+    const int top = glyph->top;
+
+    const uint8_t* bitmap = &font.getData(style)->bitmap[offset];
+
+    if (bitmap != nullptr) {
+      for (int glyphY = 0; glyphY < height; glyphY++) {
+        for (int glyphX = 0; glyphX < width; glyphX++) {
+          const int pixelPosition = glyphY * width + glyphX;
+
+          // 90° clockwise rotation transformation:
+          // screenX = x + (ascender - top + glyphY)
+          // screenY = yPos - (left + glyphX)
+          const int screenX = x + (font.getData(style)->ascender - top + glyphY);
+          const int screenY = yPos - left - glyphX;
+
+          if (is2Bit) {
+            const uint8_t byte = bitmap[pixelPosition / 4];
+            const uint8_t bit_index = (3 - pixelPosition % 4) * 2;
+            const uint8_t bmpVal = 3 - (byte >> bit_index) & 0x3;
+
+            if (renderMode == BW && bmpVal < 3) {
+              drawPixel(screenX, screenY, black);
+            } else if (renderMode == GRAYSCALE_MSB && (bmpVal == 1 || bmpVal == 2)) {
+              drawPixel(screenX, screenY, false);
+            } else if (renderMode == GRAYSCALE_LSB && bmpVal == 1) {
+              drawPixel(screenX, screenY, false);
+            }
+          } else {
+            const uint8_t byte = bitmap[pixelPosition / 8];
+            const uint8_t bit_index = 7 - (pixelPosition % 8);
+
+            if ((byte >> bit_index) & 1) {
+              drawPixel(screenX, screenY, black);
+            }
+          }
+        }
+      }
+    }
+
+    // Move to next character position (going up, so decrease Y)
+    yPos -= glyph->advanceX;
+  }
+}
+
 uint8_t* GfxRenderer::getFrameBuffer() const { return einkDisplay.getFrameBuffer(); }
 
 size_t GfxRenderer::getBufferSize() { return EInkDisplay::BUFFER_SIZE; }
@@ -436,7 +602,7 @@ void GfxRenderer::cleanupGrayscaleWithFrameBuffer() const {
 }
 
 void GfxRenderer::renderChar(const EpdFontFamily& fontFamily, const uint32_t cp, int* x, const int* y,
-                             const bool pixelState, const EpdFontStyle style) const {
+                             const bool pixelState, const EpdFontFamily::Style style) const {
   const EpdGlyph* glyph = fontFamily.getGlyph(cp, style);
   if (!glyph) {
     // TODO: Replace with fallback glyph property?

lib/GfxRenderer/GfxRenderer.h

@@ -31,7 +31,7 @@ class GfxRenderer {
   uint8_t* bwBufferChunks[BW_BUFFER_NUM_CHUNKS] = {nullptr};
   std::map<int, EpdFontFamily> fontMap;
   void renderChar(const EpdFontFamily& fontFamily, uint32_t cp, int* x, const int* y, bool pixelState,
-                  EpdFontStyle style) const;
+                  EpdFontFamily::Style style) const;
   void freeBwBufferChunks();
   void rotateCoordinates(int x, int y, int* rotatedX, int* rotatedY) const;
 
@@ -66,19 +66,32 @@ class GfxRenderer {
   void drawRect(int x, int y, int width, int height, bool state = true) const;
   void fillRect(int x, int y, int width, int height, bool state = true) const;
   void drawImage(const uint8_t bitmap[], int x, int y, int width, int height) const;
-  void drawBitmap(const Bitmap& bitmap, int x, int y, int maxWidth, int maxHeight) const;
+  void drawBitmap(const Bitmap& bitmap, int x, int y, int maxWidth, int maxHeight, float cropX = 0,
+                  float cropY = 0) const;
 
   // Text
-  int getTextWidth(int fontId, const char* text, EpdFontStyle style = REGULAR) const;
+  int getTextWidth(int fontId, const char* text, EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
-  void drawCenteredText(int fontId, int y, const char* text, bool black = true, EpdFontStyle style = REGULAR) const;
+  void drawCenteredText(int fontId, int y, const char* text, bool black = true,
-  void drawText(int fontId, int x, int y, const char* text, bool black = true, EpdFontStyle style = REGULAR) const;
+                        EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
+  void drawText(int fontId, int x, int y, const char* text, bool black = true,
+                EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
   int getSpaceWidth(int fontId) const;
   int getFontAscenderSize(int fontId) const;
   int getLineHeight(int fontId) const;
+  std::string truncatedText(int fontId, const char* text, int maxWidth,
+                            EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
 
   // UI Components
   void drawButtonHints(int fontId, const char* btn1, const char* btn2, const char* btn3, const char* btn4) const;
+  void drawSideButtonHints(int fontId, const char* topBtn, const char* bottomBtn) const;
 
+ private:
+  // Helper for drawing rotated text (90 degrees clockwise, for side buttons)
+  void drawTextRotated90CW(int fontId, int x, int y, const char* text, bool black = true,
+                           EpdFontFamily::Style style = EpdFontFamily::REGULAR) const;
+  int getTextHeight(int fontId) const;
+
+ public:
   // Grayscale functions
   void setRenderMode(const RenderMode mode) { this->renderMode = mode; }
   void copyGrayscaleLsbBuffers() const;

lib/JpegToBmpConverter/JpegToBmpConverter.cpp

@@ -7,6 +7,8 @@
 #include <cstdio>
 #include <cstring>
 
+#include "BitmapHelpers.h"
+
 // Context structure for picojpeg callback
 struct JpegReadContext {
   FsFile& file;
@@ -23,282 +25,12 @@ constexpr bool USE_8BIT_OUTPUT = false;  // true: 8-bit grayscale (no quantizati
 constexpr bool USE_ATKINSON = true;          // Atkinson dithering (cleaner than F-S, less error diffusion)
 constexpr bool USE_FLOYD_STEINBERG = false;  // Floyd-Steinberg error diffusion (can cause "worm" artifacts)
 constexpr bool USE_NOISE_DITHERING = false;  // Hash-based noise dithering (good for downsampling)
-// Brightness/Contrast adjustments:
-constexpr bool USE_BRIGHTNESS = true;     // true: apply brightness/gamma adjustments
-constexpr int BRIGHTNESS_BOOST = 10;      // Brightness offset (0-50)
-constexpr bool GAMMA_CORRECTION = true;   // Gamma curve (brightens midtones)
-constexpr float CONTRAST_FACTOR = 1.15f;  // Contrast multiplier (1.0 = no change, >1 = more contrast)
 // Pre-resize to target display size (CRITICAL: avoids dithering artifacts from post-downsampling)
 constexpr bool USE_PRESCALE = true;     // true: scale image to target size before dithering
 constexpr int TARGET_MAX_WIDTH = 480;   // Max width for cover images (portrait display width)
 constexpr int TARGET_MAX_HEIGHT = 800;  // Max height for cover images (portrait display height)
 // ============================================================================
 
-// Integer approximation of gamma correction (brightens midtones)
-// Uses a simple curve: out = 255 * sqrt(in/255) ≈ sqrt(in * 255)
-static inline int applyGamma(int gray) {
-  if (!GAMMA_CORRECTION) return gray;
-  // Fast integer square root approximation for gamma ~0.5 (brightening)
-  // This brightens dark/mid tones while preserving highlights
-  const int product = gray * 255;
-  // Newton-Raphson integer sqrt (2 iterations for good accuracy)
-  int x = gray;
-  if (x > 0) {
-    x = (x + product / x) >> 1;
-    x = (x + product / x) >> 1;
-  }
-  return x > 255 ? 255 : x;
-}
-
-// Apply contrast adjustment around midpoint (128)
-// factor > 1.0 increases contrast, < 1.0 decreases
-static inline int applyContrast(int gray) {
-  // Integer-based contrast: (gray - 128) * factor + 128
-  // Using fixed-point: factor 1.15 ≈ 115/100
-  constexpr int factorNum = static_cast<int>(CONTRAST_FACTOR * 100);
-  int adjusted = ((gray - 128) * factorNum) / 100 + 128;
-  if (adjusted < 0) adjusted = 0;
-  if (adjusted > 255) adjusted = 255;
-  return adjusted;
-}
-
-// Combined brightness/contrast/gamma adjustment
-static inline int adjustPixel(int gray) {
-  if (!USE_BRIGHTNESS) return gray;
-
-  // Order: contrast first, then brightness, then gamma
-  gray = applyContrast(gray);
-  gray += BRIGHTNESS_BOOST;
-  if (gray > 255) gray = 255;
-  if (gray < 0) gray = 0;
-  gray = applyGamma(gray);
-
-  return gray;
-}
-
-// Simple quantization without dithering - just divide into 4 levels
-static inline uint8_t quantizeSimple(int gray) {
-  gray = adjustPixel(gray);
-  // Simple 2-bit quantization: 0-63=0, 64-127=1, 128-191=2, 192-255=3
-  return static_cast<uint8_t>(gray >> 6);
-}
-
-// Hash-based noise dithering - survives downsampling without moiré artifacts
-// Uses integer hash to generate pseudo-random threshold per pixel
-static inline uint8_t quantizeNoise(int gray, int x, int y) {
-  gray = adjustPixel(gray);
-
-  // Generate noise threshold using integer hash (no regular pattern to alias)
-  uint32_t hash = static_cast<uint32_t>(x) * 374761393u + static_cast<uint32_t>(y) * 668265263u;
-  hash = (hash ^ (hash >> 13)) * 1274126177u;
-  const int threshold = static_cast<int>(hash >> 24);  // 0-255
-
-  // Map gray (0-255) to 4 levels with dithering
-  const int scaled = gray * 3;
-
-  if (scaled < 255) {
-    return (scaled + threshold >= 255) ? 1 : 0;
-  } else if (scaled < 510) {
-    return ((scaled - 255) + threshold >= 255) ? 2 : 1;
-  } else {
-    return ((scaled - 510) + threshold >= 255) ? 3 : 2;
-  }
-}
-
-// Main quantization function - selects between methods based on config
-static inline uint8_t quantize(int gray, int x, int y) {
-  if (USE_NOISE_DITHERING) {
-    return quantizeNoise(gray, x, y);
-  } else {
-    return quantizeSimple(gray);
-  }
-}
-
-// Atkinson dithering - distributes only 6/8 (75%) of error for cleaner results
-// Error distribution pattern:
-//     X  1/8 1/8
-// 1/8 1/8 1/8
-//     1/8
-// Less error buildup = fewer artifacts than Floyd-Steinberg
-class AtkinsonDitherer {
- public:
-  AtkinsonDitherer(int width) : width(width) {
-    errorRow0 = new int16_t[width + 4]();  // Current row
-    errorRow1 = new int16_t[width + 4]();  // Next row
-    errorRow2 = new int16_t[width + 4]();  // Row after next
-  }
-
-  ~AtkinsonDitherer() {
-    delete[] errorRow0;
-    delete[] errorRow1;
-    delete[] errorRow2;
-  }
-
-  uint8_t processPixel(int gray, int x) {
-    // Apply brightness/contrast/gamma adjustments
-    gray = adjustPixel(gray);
-
-    // Add accumulated error
-    int adjusted = gray + errorRow0[x + 2];
-    if (adjusted < 0) adjusted = 0;
-    if (adjusted > 255) adjusted = 255;
-
-    // Quantize to 4 levels
-    uint8_t quantized;
-    int quantizedValue;
-    if (adjusted < 43) {
-      quantized = 0;
-      quantizedValue = 0;
-    } else if (adjusted < 128) {
-      quantized = 1;
-      quantizedValue = 85;
-    } else if (adjusted < 213) {
-      quantized = 2;
-      quantizedValue = 170;
-    } else {
-      quantized = 3;
-      quantizedValue = 255;
-    }
-
-    // Calculate error (only distribute 6/8 = 75%)
-    int error = (adjusted - quantizedValue) >> 3;  // error/8
-
-    // Distribute 1/8 to each of 6 neighbors
-    errorRow0[x + 3] += error;  // Right
-    errorRow0[x + 4] += error;  // Right+1
-    errorRow1[x + 1] += error;  // Bottom-left
-    errorRow1[x + 2] += error;  // Bottom
-    errorRow1[x + 3] += error;  // Bottom-right
-    errorRow2[x + 2] += error;  // Two rows down
-
-    return quantized;
-  }
-
-  void nextRow() {
-    int16_t* temp = errorRow0;
-    errorRow0 = errorRow1;
-    errorRow1 = errorRow2;
-    errorRow2 = temp;
-    memset(errorRow2, 0, (width + 4) * sizeof(int16_t));
-  }
-
-  void reset() {
-    memset(errorRow0, 0, (width + 4) * sizeof(int16_t));
-    memset(errorRow1, 0, (width + 4) * sizeof(int16_t));
-    memset(errorRow2, 0, (width + 4) * sizeof(int16_t));
-  }
-
- private:
-  int width;
-  int16_t* errorRow0;
-  int16_t* errorRow1;
-  int16_t* errorRow2;
-};
-
-// Floyd-Steinberg error diffusion dithering with serpentine scanning
-// Serpentine scanning alternates direction each row to reduce "worm" artifacts
-// Error distribution pattern (left-to-right):
-//       X   7/16
-// 3/16 5/16 1/16
-// Error distribution pattern (right-to-left, mirrored):
-// 1/16 5/16 3/16
-//      7/16  X
-class FloydSteinbergDitherer {
- public:
-  FloydSteinbergDitherer(int width) : width(width), rowCount(0) {
-    errorCurRow = new int16_t[width + 2]();  // +2 for boundary handling
-    errorNextRow = new int16_t[width + 2]();
-  }
-
-  ~FloydSteinbergDitherer() {
-    delete[] errorCurRow;
-    delete[] errorNextRow;
-  }
-
-  // Process a single pixel and return quantized 2-bit value
-  // x is the logical x position (0 to width-1), direction handled internally
-  uint8_t processPixel(int gray, int x, bool reverseDirection) {
-    // Add accumulated error to this pixel
-    int adjusted = gray + errorCurRow[x + 1];
-
-    // Clamp to valid range
-    if (adjusted < 0) adjusted = 0;
-    if (adjusted > 255) adjusted = 255;
-
-    // Quantize to 4 levels (0, 85, 170, 255)
-    uint8_t quantized;
-    int quantizedValue;
-    if (adjusted < 43) {
-      quantized = 0;
-      quantizedValue = 0;
-    } else if (adjusted < 128) {
-      quantized = 1;
-      quantizedValue = 85;
-    } else if (adjusted < 213) {
-      quantized = 2;
-      quantizedValue = 170;
-    } else {
-      quantized = 3;
-      quantizedValue = 255;
-    }
-
-    // Calculate error
-    int error = adjusted - quantizedValue;
-
-    // Distribute error to neighbors (serpentine: direction-aware)
-    if (!reverseDirection) {
-      // Left to right: standard distribution
-      // Right: 7/16
-      errorCurRow[x + 2] += (error * 7) >> 4;
-      // Bottom-left: 3/16
-      errorNextRow[x] += (error * 3) >> 4;
-      // Bottom: 5/16
-      errorNextRow[x + 1] += (error * 5) >> 4;
-      // Bottom-right: 1/16
-      errorNextRow[x + 2] += (error) >> 4;
-    } else {
-      // Right to left: mirrored distribution
-      // Left: 7/16
-      errorCurRow[x] += (error * 7) >> 4;
-      // Bottom-right: 3/16
-      errorNextRow[x + 2] += (error * 3) >> 4;
-      // Bottom: 5/16
-      errorNextRow[x + 1] += (error * 5) >> 4;
-      // Bottom-left: 1/16
-      errorNextRow[x] += (error) >> 4;
-    }
-
-    return quantized;
-  }
-
-  // Call at the end of each row to swap buffers
-  void nextRow() {
-    // Swap buffers
-    int16_t* temp = errorCurRow;
-    errorCurRow = errorNextRow;
-    errorNextRow = temp;
-    // Clear the next row buffer
-    memset(errorNextRow, 0, (width + 2) * sizeof(int16_t));
-    rowCount++;
-  }
-
-  // Check if current row should be processed in reverse
-  bool isReverseRow() const { return (rowCount & 1) != 0; }
-
-  // Reset for a new image or MCU block
-  void reset() {
-    memset(errorCurRow, 0, (width + 2) * sizeof(int16_t));
-    memset(errorNextRow, 0, (width + 2) * sizeof(int16_t));
-    rowCount = 0;
-  }
-
- private:
-  int width;
-  int rowCount;
-  int16_t* errorCurRow;
-  int16_t* errorNextRow;
-};
-
 inline void write16(Print& out, const uint16_t value) {
   out.write(value & 0xFF);
   out.write((value >> 8) & 0xFF);
@@ -468,7 +200,9 @@ bool JpegToBmpConverter::jpegFileToBmpStream(FsFile& jpegFile, Print& bmpOut) {
     // Calculate scale to fit within target dimensions while maintaining aspect ratio
     const float scaleToFitWidth = static_cast<float>(TARGET_MAX_WIDTH) / imageInfo.m_width;
     const float scaleToFitHeight = static_cast<float>(TARGET_MAX_HEIGHT) / imageInfo.m_height;
-    const float scale = (scaleToFitWidth < scaleToFitHeight) ? scaleToFitWidth : scaleToFitHeight;
+    // We scale to the smaller dimension, so we can potentially crop later.
+    // TODO: ideally, we already crop here.
+    const float scale = (scaleToFitWidth > scaleToFitHeight) ? scaleToFitWidth : scaleToFitHeight;
 
     outWidth = static_cast<int>(imageInfo.m_width * scale);
     outHeight = static_cast<int>(imageInfo.m_height * scale);
@@ -621,12 +355,12 @@ bool JpegToBmpConverter::jpegFileToBmpStream(FsFile& jpegFile, Print& bmpOut) {
           }
         } else {
           for (int x = 0; x < outWidth; x++) {
-            const uint8_t gray = mcuRowBuffer[bufferY * imageInfo.m_width + x];
+            const uint8_t gray = adjustPixel(mcuRowBuffer[bufferY * imageInfo.m_width + x]);
             uint8_t twoBit;
             if (atkinsonDitherer) {
               twoBit = atkinsonDitherer->processPixel(gray, x);
             } else if (fsDitherer) {
-              twoBit = fsDitherer->processPixel(gray, x, fsDitherer->isReverseRow());
+              twoBit = fsDitherer->processPixel(gray, x);
             } else {
               twoBit = quantize(gray, x, y);
             }
@@ -684,12 +418,12 @@ bool JpegToBmpConverter::jpegFileToBmpStream(FsFile& jpegFile, Print& bmpOut) {
             }
           } else {
             for (int x = 0; x < outWidth; x++) {
-              const uint8_t gray = (rowCount[x] > 0) ? (rowAccum[x] / rowCount[x]) : 0;
+              const uint8_t gray = adjustPixel((rowCount[x] > 0) ? (rowAccum[x] / rowCount[x]) : 0);
               uint8_t twoBit;
               if (atkinsonDitherer) {
                 twoBit = atkinsonDitherer->processPixel(gray, x);
               } else if (fsDitherer) {
-                twoBit = fsDitherer->processPixel(gray, x, fsDitherer->isReverseRow());
+                twoBit = fsDitherer->processPixel(gray, x);
               } else {
                 twoBit = quantize(gray, x, currentOutY);
               }

lib/OpdsParser/OpdsParser.cpp

@@ -0,0 +1,219 @@
+#include "OpdsParser.h"
+
+#include <HardwareSerial.h>
+
+#include <cstring>
+
+OpdsParser::~OpdsParser() {
+  if (parser) {
+    XML_StopParser(parser, XML_FALSE);
+    XML_SetElementHandler(parser, nullptr, nullptr);
+    XML_SetCharacterDataHandler(parser, nullptr);
+    XML_ParserFree(parser);
+    parser = nullptr;
+  }
+}
+
+bool OpdsParser::parse(const char* xmlData, const size_t length) {
+  clear();
+
+  parser = XML_ParserCreate(nullptr);
+  if (!parser) {
+    Serial.printf("[%lu] [OPDS] Couldn't allocate memory for parser\n", millis());
+    return false;
+  }
+
+  XML_SetUserData(parser, this);
+  XML_SetElementHandler(parser, startElement, endElement);
+  XML_SetCharacterDataHandler(parser, characterData);
+
+  // Parse in chunks to avoid large buffer allocations
+  const char* currentPos = xmlData;
+  size_t remaining = length;
+  constexpr size_t chunkSize = 1024;
+
+  while (remaining > 0) {
+    void* const buf = XML_GetBuffer(parser, chunkSize);
+    if (!buf) {
+      Serial.printf("[%lu] [OPDS] Couldn't allocate memory for buffer\n", millis());
+      XML_ParserFree(parser);
+      parser = nullptr;
+      return false;
+    }
+
+    const size_t toRead = remaining < chunkSize ? remaining : chunkSize;
+    memcpy(buf, currentPos, toRead);
+
+    const bool isFinal = (remaining == toRead);
+    if (XML_ParseBuffer(parser, static_cast<int>(toRead), isFinal) == XML_STATUS_ERROR) {
+      Serial.printf("[%lu] [OPDS] Parse error at line %lu: %s\n", millis(), XML_GetCurrentLineNumber(parser),
+                    XML_ErrorString(XML_GetErrorCode(parser)));
+      XML_ParserFree(parser);
+      parser = nullptr;
+      return false;
+    }
+
+    currentPos += toRead;
+    remaining -= toRead;
+  }
+
+  // Clean up parser
+  XML_ParserFree(parser);
+  parser = nullptr;
+
+  Serial.printf("[%lu] [OPDS] Parsed %zu entries\n", millis(), entries.size());
+  return true;
+}
+
+void OpdsParser::clear() {
+  entries.clear();
+  currentEntry = OpdsEntry{};
+  currentText.clear();
+  inEntry = false;
+  inTitle = false;
+  inAuthor = false;
+  inAuthorName = false;
+  inId = false;
+}
+
+std::vector<OpdsEntry> OpdsParser::getBooks() const {
+  std::vector<OpdsEntry> books;
+  for (const auto& entry : entries) {
+    if (entry.type == OpdsEntryType::BOOK) {
+      books.push_back(entry);
+    }
+  }
+  return books;
+}
+
+const char* OpdsParser::findAttribute(const XML_Char** atts, const char* name) {
+  for (int i = 0; atts[i]; i += 2) {
+    if (strcmp(atts[i], name) == 0) {
+      return atts[i + 1];
+    }
+  }
+  return nullptr;
+}
+
+void XMLCALL OpdsParser::startElement(void* userData, const XML_Char* name, const XML_Char** atts) {
+  auto* self = static_cast<OpdsParser*>(userData);
+
+  // Check for entry element (with or without namespace prefix)
+  if (strcmp(name, "entry") == 0 || strstr(name, ":entry") != nullptr) {
+    self->inEntry = true;
+    self->currentEntry = OpdsEntry{};
+    return;
+  }
+
+  if (!self->inEntry) return;
+
+  // Check for title element
+  if (strcmp(name, "title") == 0 || strstr(name, ":title") != nullptr) {
+    self->inTitle = true;
+    self->currentText.clear();
+    return;
+  }
+
+  // Check for author element
+  if (strcmp(name, "author") == 0 || strstr(name, ":author") != nullptr) {
+    self->inAuthor = true;
+    return;
+  }
+
+  // Check for author name element
+  if (self->inAuthor && (strcmp(name, "name") == 0 || strstr(name, ":name") != nullptr)) {
+    self->inAuthorName = true;
+    self->currentText.clear();
+    return;
+  }
+
+  // Check for id element
+  if (strcmp(name, "id") == 0 || strstr(name, ":id") != nullptr) {
+    self->inId = true;
+    self->currentText.clear();
+    return;
+  }
+
+  // Check for link element
+  if (strcmp(name, "link") == 0 || strstr(name, ":link") != nullptr) {
+    const char* rel = findAttribute(atts, "rel");
+    const char* type = findAttribute(atts, "type");
+    const char* href = findAttribute(atts, "href");
+
+    if (href) {
+      // Check for acquisition link with epub type (this is a downloadable book)
+      if (rel && type && strstr(rel, "opds-spec.org/acquisition") != nullptr &&
+          strcmp(type, "application/epub+zip") == 0) {
+        self->currentEntry.type = OpdsEntryType::BOOK;
+        self->currentEntry.href = href;
+      }
+      // Check for navigation link (subsection or no rel specified with atom+xml type)
+      else if (type && strstr(type, "application/atom+xml") != nullptr) {
+        // Only set navigation link if we don't already have an epub link
+        if (self->currentEntry.type != OpdsEntryType::BOOK) {
+          self->currentEntry.type = OpdsEntryType::NAVIGATION;
+          self->currentEntry.href = href;
+        }
+      }
+    }
+  }
+}
+
+void XMLCALL OpdsParser::endElement(void* userData, const XML_Char* name) {
+  auto* self = static_cast<OpdsParser*>(userData);
+
+  // Check for entry end
+  if (strcmp(name, "entry") == 0 || strstr(name, ":entry") != nullptr) {
+    // Only add entry if it has required fields (title and href)
+    if (!self->currentEntry.title.empty() && !self->currentEntry.href.empty()) {
+      self->entries.push_back(self->currentEntry);
+    }
+    self->inEntry = false;
+    self->currentEntry = OpdsEntry{};
+    return;
+  }
+
+  if (!self->inEntry) return;
+
+  // Check for title end
+  if (strcmp(name, "title") == 0 || strstr(name, ":title") != nullptr) {
+    if (self->inTitle) {
+      self->currentEntry.title = self->currentText;
+    }
+    self->inTitle = false;
+    return;
+  }
+
+  // Check for author end
+  if (strcmp(name, "author") == 0 || strstr(name, ":author") != nullptr) {
+    self->inAuthor = false;
+    return;
+  }
+
+  // Check for author name end
+  if (self->inAuthor && (strcmp(name, "name") == 0 || strstr(name, ":name") != nullptr)) {
+    if (self->inAuthorName) {
+      self->currentEntry.author = self->currentText;
+    }
+    self->inAuthorName = false;
+    return;
+  }
+
+  // Check for id end
+  if (strcmp(name, "id") == 0 || strstr(name, ":id") != nullptr) {
+    if (self->inId) {
+      self->currentEntry.id = self->currentText;
+    }
+    self->inId = false;
+    return;
+  }
+}
+
+void XMLCALL OpdsParser::characterData(void* userData, const XML_Char* s, const int len) {
+  auto* self = static_cast<OpdsParser*>(userData);
+
+  // Only accumulate text when in a text element
+  if (self->inTitle || self->inAuthorName || self->inId) {
+    self->currentText.append(s, len);
+  }
+}

lib/OpdsParser/OpdsParser.h

@@ -0,0 +1,99 @@
+#pragma once
+#include <expat.h>
+
+#include <string>
+#include <vector>
+
+/**
+ * Type of OPDS entry.
+ */
+enum class OpdsEntryType {
+  NAVIGATION,  // Link to another catalog
+  BOOK         // Downloadable book
+};
+
+/**
+ * Represents an entry from an OPDS feed (either a navigation link or a book).
+ */
+struct OpdsEntry {
+  OpdsEntryType type = OpdsEntryType::NAVIGATION;
+  std::string title;
+  std::string author;  // Only for books
+  std::string href;    // Navigation URL or epub download URL
+  std::string id;
+};
+
+// Legacy alias for backward compatibility
+using OpdsBook = OpdsEntry;
+
+/**
+ * Parser for OPDS (Open Publication Distribution System) Atom feeds.
+ * Uses the Expat XML parser to parse OPDS catalog entries.
+ *
+ * Usage:
+ *   OpdsParser parser;
+ *   if (parser.parse(xmlData, xmlLength)) {
+ *     for (const auto& entry : parser.getEntries()) {
+ *       if (entry.type == OpdsEntryType::BOOK) {
+ *         // Downloadable book
+ *       } else {
+ *         // Navigation link to another catalog
+ *       }
+ *     }
+ *   }
+ */
+class OpdsParser {
+ public:
+  OpdsParser() = default;
+  ~OpdsParser();
+
+  // Disable copy
+  OpdsParser(const OpdsParser&) = delete;
+  OpdsParser& operator=(const OpdsParser&) = delete;
+
+  /**
+   * Parse an OPDS XML feed.
+   * @param xmlData Pointer to the XML data
+   * @param length Length of the XML data
+   * @return true if parsing succeeded, false on error
+   */
+  bool parse(const char* xmlData, size_t length);
+
+  /**
+   * Get the parsed entries (both navigation and book entries).
+   * @return Vector of OpdsEntry entries
+   */
+  const std::vector<OpdsEntry>& getEntries() const { return entries; }
+
+  /**
+   * Get only book entries (legacy compatibility).
+   * @return Vector of book entries
+   */
+  std::vector<OpdsEntry> getBooks() const;
+
+  /**
+   * Clear all parsed entries.
+   */
+  void clear();
+
+ private:
+  // Expat callbacks
+  static void XMLCALL startElement(void* userData, const XML_Char* name, const XML_Char** atts);
+  static void XMLCALL endElement(void* userData, const XML_Char* name);
+  static void XMLCALL characterData(void* userData, const XML_Char* s, int len);
+
+  // Helper to find attribute value
+  static const char* findAttribute(const XML_Char** atts, const char* name);
+
+  XML_Parser parser = nullptr;
+  std::vector<OpdsEntry> entries;
+  OpdsEntry currentEntry;
+  std::string currentText;
+
+  // Parser state
+  bool inEntry = false;
+  bool inTitle = false;
+  bool inAuthor = false;
+  bool inAuthorName = false;
+  bool inId = false;
+};

platformio.ini

@@ -1,7 +1,9 @@
 [platformio]
-crosspoint_version = 0.11.1
 default_envs = default
 
+[crosspoint]
+version = 0.13.0
+
 [base]
 platform = espressif32 @ 6.12.0
 board = esp32-c3-devkitm-1
@@ -26,6 +28,8 @@ build_flags =
   -DXML_GE=0
   -DXML_CONTEXT_BYTES=1024
   -std=c++2a
+# Enable UTF-8 long file names in SdFat
+  -DUSE_UTF8_LONG_NAMES=1
 
 ; Board configuration
 board_build.flash_mode = dio
@@ -48,10 +52,10 @@ lib_deps =
 extends = base
 build_flags =
   ${base.build_flags}
-  -DCROSSPOINT_VERSION=\"${platformio.crosspoint_version}-dev\"
+  -DCROSSPOINT_VERSION=\"${crosspoint.version}-dev\"
 
 [env:gh_release]
 extends = base
 build_flags =
   ${base.build_flags}
-  -DCROSSPOINT_VERSION=\"${platformio.crosspoint_version}\"
+  -DCROSSPOINT_VERSION=\"${crosspoint.version}\"

src/CrossPointSettings.cpp

@@ -4,6 +4,8 @@
 #include <SDCardManager.h>
 #include <Serialization.h>
 
+#include <cstring>
+
 #include "fontIds.h"
 
 // Initialize the static instance
@@ -12,7 +14,7 @@ CrossPointSettings CrossPointSettings::instance;
 namespace {
 constexpr uint8_t SETTINGS_FILE_VERSION = 1;
 // Increment this when adding new persisted settings fields
-constexpr uint8_t SETTINGS_COUNT = 10;
+constexpr uint8_t SETTINGS_COUNT = 17;
 constexpr char SETTINGS_FILE[] = "/.crosspoint/settings.bin";
 }  // namespace
 
@@ -37,6 +39,14 @@ bool CrossPointSettings::saveToFile() const {
   serialization::writePod(outputFile, fontFamily);
   serialization::writePod(outputFile, fontSize);
   serialization::writePod(outputFile, lineSpacing);
+  serialization::writePod(outputFile, paragraphAlignment);
+  serialization::writePod(outputFile, sleepTimeout);
+  serialization::writePod(outputFile, refreshFrequency);
+  serialization::writePod(outputFile, screenMargin);
+  serialization::writePod(outputFile, sleepScreenCoverMode);
+  serialization::writeString(outputFile, std::string(opdsServerUrl));
+  serialization::writePod(outputFile, textAntiAliasing);
+  serialization::writePod(outputFile, hideBatteryPercentage);
   outputFile.close();
 
   Serial.printf("[%lu] [CPS] Settings saved to file\n", millis());
@@ -83,6 +93,26 @@ bool CrossPointSettings::loadFromFile() {
     if (++settingsRead >= fileSettingsCount) break;
     serialization::readPod(inputFile, lineSpacing);
     if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, paragraphAlignment);
+    if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, sleepTimeout);
+    if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, refreshFrequency);
+    if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, screenMargin);
+    if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, sleepScreenCoverMode);
+    if (++settingsRead >= fileSettingsCount) break;
+    {
+      std::string urlStr;
+      serialization::readString(inputFile, urlStr);
+      strncpy(opdsServerUrl, urlStr.c_str(), sizeof(opdsServerUrl) - 1);
+      opdsServerUrl[sizeof(opdsServerUrl) - 1] = '\0';
+    }
+    serialization::readPod(inputFile, textAntiAliasing);
+    if (++settingsRead >= fileSettingsCount) break;
+    serialization::readPod(inputFile, hideBatteryPercentage);
+    if (++settingsRead >= fileSettingsCount) break;
   } while (false);
 
   inputFile.close();
@@ -126,6 +156,38 @@ float CrossPointSettings::getReaderLineCompression() const {
   }
 }
 
+unsigned long CrossPointSettings::getSleepTimeoutMs() const {
+  switch (sleepTimeout) {
+    case SLEEP_1_MIN:
+      return 1UL * 60 * 1000;
+    case SLEEP_5_MIN:
+      return 5UL * 60 * 1000;
+    case SLEEP_10_MIN:
+    default:
+      return 10UL * 60 * 1000;
+    case SLEEP_15_MIN:
+      return 15UL * 60 * 1000;
+    case SLEEP_30_MIN:
+      return 30UL * 60 * 1000;
+  }
+}
+
+int CrossPointSettings::getRefreshFrequency() const {
+  switch (refreshFrequency) {
+    case REFRESH_1:
+      return 1;
+    case REFRESH_5:
+      return 5;
+    case REFRESH_10:
+      return 10;
+    case REFRESH_15:
+    default:
+      return 15;
+    case REFRESH_30:
+      return 30;
+  }
+}
+
 int CrossPointSettings::getReaderFontId() const {
   switch (fontFamily) {
     case BOOKERLY:

src/CrossPointSettings.h

@@ -16,7 +16,8 @@ class CrossPointSettings {
   CrossPointSettings& operator=(const CrossPointSettings&) = delete;
 
   // Should match with SettingsActivity text
-  enum SLEEP_SCREEN_MODE { DARK = 0, LIGHT = 1, CUSTOM = 2, COVER = 3 };
+  enum SLEEP_SCREEN_MODE { DARK = 0, LIGHT = 1, CUSTOM = 2, COVER = 3, BLANK = 4 };
+  enum SLEEP_SCREEN_COVER_MODE { FIT = 0, CROP = 1 };
 
   // Status bar display type enum
   enum STATUS_BAR_MODE { NONE = 0, NO_PROGRESS = 1, FULL = 2 };
@@ -43,15 +44,31 @@ class CrossPointSettings {
   // Font size options
   enum FONT_SIZE { SMALL = 0, MEDIUM = 1, LARGE = 2, EXTRA_LARGE = 3 };
   enum LINE_COMPRESSION { TIGHT = 0, NORMAL = 1, WIDE = 2 };
+  enum PARAGRAPH_ALIGNMENT { JUSTIFIED = 0, LEFT_ALIGN = 1, CENTER_ALIGN = 2, RIGHT_ALIGN = 3 };
+
+  // Auto-sleep timeout options (in minutes)
+  enum SLEEP_TIMEOUT { SLEEP_1_MIN = 0, SLEEP_5_MIN = 1, SLEEP_10_MIN = 2, SLEEP_15_MIN = 3, SLEEP_30_MIN = 4 };
+
+  // E-ink refresh frequency (pages between full refreshes)
+  enum REFRESH_FREQUENCY { REFRESH_1 = 0, REFRESH_5 = 1, REFRESH_10 = 2, REFRESH_15 = 3, REFRESH_30 = 4 };
+
+  // Short power button press actions
+  enum SHORT_PWRBTN { IGNORE = 0, SLEEP = 1, PAGE_TURN = 2 };
+
+  // Hide battery percentage
+  enum HIDE_BATTERY_PERCENTAGE { HIDE_NEVER = 0, HIDE_READER = 1, HIDE_ALWAYS = 2 };
 
   // Sleep screen settings
   uint8_t sleepScreen = DARK;
+  // Sleep screen cover mode settings
+  uint8_t sleepScreenCoverMode = FIT;
   // Status bar settings
   uint8_t statusBar = FULL;
   // Text rendering settings
   uint8_t extraParagraphSpacing = 1;
-  // Duration of the power button press
+  uint8_t textAntiAliasing = 1;
-  uint8_t shortPwrBtn = 0;
+  // Short power button click behaviour
+  uint8_t shortPwrBtn = IGNORE;
   // EPUB reading orientation settings
   // 0 = portrait (default), 1 = landscape clockwise, 2 = inverted, 3 = landscape counter-clockwise
   uint8_t orientation = PORTRAIT;
@@ -62,19 +79,34 @@ class CrossPointSettings {
   uint8_t fontFamily = BOOKERLY;
   uint8_t fontSize = MEDIUM;
   uint8_t lineSpacing = NORMAL;
+  uint8_t paragraphAlignment = JUSTIFIED;
+  // Auto-sleep timeout setting (default 10 minutes)
+  uint8_t sleepTimeout = SLEEP_10_MIN;
+  // E-ink refresh frequency (default 15 pages)
+  uint8_t refreshFrequency = REFRESH_15;
+  // Reader screen margin settings
+  uint8_t screenMargin = 5;
+  // OPDS browser settings
+  char opdsServerUrl[128] = "";
+  // Hide battery percentage
+  uint8_t hideBatteryPercentage = HIDE_NEVER;
 
   ~CrossPointSettings() = default;
 
   // Get singleton instance
   static CrossPointSettings& getInstance() { return instance; }
 
-  uint16_t getPowerButtonDuration() const { return shortPwrBtn ? 10 : 400; }
+  uint16_t getPowerButtonDuration() const {
+    return (shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::SLEEP) ? 10 : 400;
+  }
   int getReaderFontId() const;
 
   bool saveToFile() const;
   bool loadFromFile();
 
   float getReaderLineCompression() const;
+  unsigned long getSleepTimeoutMs() const;
+  int getRefreshFrequency() const;
 };
 
 // Helper macro to access settings

src/ScreenComponents.cpp

@@ -2,34 +2,36 @@
 
 #include <GfxRenderer.h>
 
+#include <cstdint>
 #include <string>
 
 #include "Battery.h"
 #include "fontIds.h"
 
-void ScreenComponents::drawBattery(const GfxRenderer& renderer, const int left, const int top) {
+void ScreenComponents::drawBattery(const GfxRenderer& renderer, const int left, const int top,
+                                   const bool showPercentage) {
   // Left aligned battery icon and percentage
   const uint16_t percentage = battery.readPercentage();
-  const auto percentageText = std::to_string(percentage) + "%";
+  const auto percentageText = showPercentage ? std::to_string(percentage) + "%" : "";
   renderer.drawText(SMALL_FONT_ID, left + 20, top, percentageText.c_str());
 
   // 1 column on left, 2 columns on right, 5 columns of battery body
   constexpr int batteryWidth = 15;
-  constexpr int batteryHeight = 10;
+  constexpr int batteryHeight = 12;
   const int x = left;
-  const int y = top + 8;
+  const int y = top + 6;
 
   // Top line
-  renderer.drawLine(x, y, x + batteryWidth - 4, y);
+  renderer.drawLine(x + 1, y, x + batteryWidth - 3, y);
   // Bottom line
-  renderer.drawLine(x, y + batteryHeight - 1, x + batteryWidth - 4, y + batteryHeight - 1);
+  renderer.drawLine(x + 1, y + batteryHeight - 1, x + batteryWidth - 3, y + batteryHeight - 1);
   // Left line
-  renderer.drawLine(x, y, x, y + batteryHeight - 1);
+  renderer.drawLine(x, y + 1, x, y + batteryHeight - 2);
   // Battery end
-  renderer.drawLine(x + batteryWidth - 4, y, x + batteryWidth - 4, y + batteryHeight - 1);
+  renderer.drawLine(x + batteryWidth - 2, y + 1, x + batteryWidth - 2, y + batteryHeight - 2);
-  renderer.drawLine(x + batteryWidth - 3, y + 2, x + batteryWidth - 1, y + 2);
+  renderer.drawPixel(x + batteryWidth - 1, y + 3);
-  renderer.drawLine(x + batteryWidth - 3, y + batteryHeight - 3, x + batteryWidth - 1, y + batteryHeight - 3);
+  renderer.drawPixel(x + batteryWidth - 1, y + batteryHeight - 4);
-  renderer.drawLine(x + batteryWidth - 1, y + 2, x + batteryWidth - 1, y + batteryHeight - 3);
+  renderer.drawLine(x + batteryWidth - 0, y + 4, x + batteryWidth - 0, y + batteryHeight - 5);
 
   // The +1 is to round up, so that we always fill at least one pixel
   int filledWidth = percentage * (batteryWidth - 5) / 100 + 1;
@@ -37,5 +39,28 @@ void ScreenComponents::drawBattery(const GfxRenderer& renderer, const int left,
     filledWidth = batteryWidth - 5;  // Ensure we don't overflow
   }
 
-  renderer.fillRect(x + 1, y + 1, filledWidth, batteryHeight - 2);
+  renderer.fillRect(x + 2, y + 2, filledWidth, batteryHeight - 4);
+}
+
+void ScreenComponents::drawProgressBar(const GfxRenderer& renderer, const int x, const int y, const int width,
+                                       const int height, const size_t current, const size_t total) {
+  if (total == 0) {
+    return;
+  }
+
+  // Use 64-bit arithmetic to avoid overflow for large files
+  const int percent = static_cast<int>((static_cast<uint64_t>(current) * 100) / total);
+
+  // Draw outline
+  renderer.drawRect(x, y, width, height);
+
+  // Draw filled portion
+  const int fillWidth = (width - 4) * percent / 100;
+  if (fillWidth > 0) {
+    renderer.fillRect(x + 2, y + 2, fillWidth, height - 4);
+  }
+
+  // Draw percentage text centered below bar
+  const std::string percentText = std::to_string(percent) + "%";
+  renderer.drawCenteredText(UI_10_FONT_ID, y + height + 15, percentText.c_str());
 }

src/ScreenComponents.h

@@ -1,8 +1,24 @@
 #pragma once
 
+#include <cstddef>
+#include <cstdint>
+
 class GfxRenderer;
 
 class ScreenComponents {
  public:
-  static void drawBattery(const GfxRenderer& renderer, int left, int top);
+  static void drawBattery(const GfxRenderer& renderer, int left, int top, bool showPercentage = true);
+
+  /**
+   * Draw a progress bar with percentage text.
+   * @param renderer The graphics renderer
+   * @param x Left position of the bar
+   * @param y Top position of the bar
+   * @param width Width of the bar
+   * @param height Height of the bar
+   * @param current Current progress value
+   * @param total Total value for 100% progress
+   */
+  static void drawProgressBar(const GfxRenderer& renderer, int x, int y, int width, int height, size_t current,
+                              size_t total);
 };

src/activities/Activity.h

@@ -22,4 +22,5 @@ class Activity {
   virtual void onExit() { Serial.printf("[%lu] [ACT] Exiting activity: %s\n", millis(), name.c_str()); }
   virtual void loop() {}
   virtual bool skipLoopDelay() { return false; }
+  virtual bool preventAutoSleep() { return false; }
 };

src/activities/boot_sleep/BootActivity.cpp

@@ -13,7 +13,7 @@ void BootActivity::onEnter() {
 
   renderer.clearScreen();
   renderer.drawImage(CrossLarge, (pageWidth + 128) / 2, (pageHeight - 128) / 2, 128, 128);
-  renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 + 70, "CrossPoint", true, BOLD);
+  renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 + 70, "CrossPoint", true, EpdFontFamily::BOLD);
   renderer.drawCenteredText(SMALL_FONT_ID, pageHeight / 2 + 95, "BOOTING");
   renderer.drawCenteredText(SMALL_FONT_ID, pageHeight - 30, CROSSPOINT_VERSION);
   renderer.displayBuffer();

src/activities/boot_sleep/SleepActivity.cpp

@@ -5,31 +5,20 @@
 #include <SDCardManager.h>
 #include <Xtc.h>
 
-#include <vector>
-
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "fontIds.h"
 #include "images/CrossLarge.h"
-
+#include "util/StringUtils.h"
-namespace {
-// Check if path has XTC extension (.xtc or .xtch)
-bool isXtcFile(const std::string& path) {
-  if (path.length() < 4) return false;
-  std::string ext4 = path.substr(path.length() - 4);
-  if (ext4 == ".xtc") return true;
-  if (path.length() >= 5) {
-    std::string ext5 = path.substr(path.length() - 5);
-    if (ext5 == ".xtch") return true;
-  }
-  return false;
-}
-}  // namespace
 
 void SleepActivity::onEnter() {
   Activity::onEnter();
   renderPopup("Entering Sleep...");
 
+  if (SETTINGS.sleepScreen == CrossPointSettings::SLEEP_SCREEN_MODE::BLANK) {
+    return renderBlankSleepScreen();
+  }
+
   if (SETTINGS.sleepScreen == CrossPointSettings::SLEEP_SCREEN_MODE::CUSTOM) {
     return renderCustomSleepScreen();
   }
@@ -42,16 +31,16 @@ void SleepActivity::onEnter() {
 }
 
 void SleepActivity::renderPopup(const char* message) const {
-  const int textWidth = renderer.getTextWidth(UI_12_FONT_ID, message);
+  const int textWidth = renderer.getTextWidth(UI_12_FONT_ID, message, EpdFontFamily::BOLD);
   constexpr int margin = 20;
   const int x = (renderer.getScreenWidth() - textWidth - margin * 2) / 2;
   constexpr int y = 117;
   const int w = textWidth + margin * 2;
   const int h = renderer.getLineHeight(UI_12_FONT_ID) + margin * 2;
   // renderer.clearScreen();
+  renderer.fillRect(x - 5, y - 5, w + 10, h + 10, true);
   renderer.fillRect(x + 5, y + 5, w - 10, h - 10, false);
-  renderer.drawText(UI_12_FONT_ID, x + margin, y + margin, message);
+  renderer.drawText(UI_12_FONT_ID, x + margin, y + margin, message, true, EpdFontFamily::BOLD);
-  renderer.drawRect(x + 5, y + 5, w - 10, h - 10);
   renderer.displayBuffer();
 }
 
@@ -60,7 +49,7 @@ void SleepActivity::renderCustomSleepScreen() const {
   auto dir = SdMan.open("/sleep");
   if (dir && dir.isDirectory()) {
     std::vector<std::string> files;
-    char name[128];
+    char name[500];
     // collect all valid BMP files
     for (auto file = dir.openNextFile(); file; file = dir.openNextFile()) {
       if (file.isDirectory()) {
@@ -97,7 +86,7 @@ void SleepActivity::renderCustomSleepScreen() const {
       if (SdMan.openFileForRead("SLP", filename, file)) {
         Serial.printf("[%lu] [SLP] Randomly loading: /sleep/%s\n", millis(), files[randomFileIndex].c_str());
         delay(100);
-        Bitmap bitmap(file);
+        Bitmap bitmap(file, true);
         if (bitmap.parseHeaders() == BmpReaderError::Ok) {
           renderBitmapSleepScreen(bitmap);
           dir.close();
@@ -112,7 +101,7 @@ void SleepActivity::renderCustomSleepScreen() const {
   // render a custom sleep screen instead of the default.
   FsFile file;
   if (SdMan.openFileForRead("SLP", "/sleep.bmp", file)) {
-    Bitmap bitmap(file);
+    Bitmap bitmap(file, true);
     if (bitmap.parseHeaders() == BmpReaderError::Ok) {
       Serial.printf("[%lu] [SLP] Loading: /sleep.bmp\n", millis());
       renderBitmapSleepScreen(bitmap);
@@ -129,7 +118,7 @@ void SleepActivity::renderDefaultSleepScreen() const {
 
   renderer.clearScreen();
   renderer.drawImage(CrossLarge, (pageWidth + 128) / 2, (pageHeight - 128) / 2, 128, 128);
-  renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 + 70, "CrossPoint", true, BOLD);
+  renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 + 70, "CrossPoint", true, EpdFontFamily::BOLD);
   renderer.drawCenteredText(SMALL_FONT_ID, pageHeight / 2 + 95, "SLEEPING");
 
   // Make sleep screen dark unless light is selected in settings
@@ -144,20 +133,36 @@ void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
   int x, y;
   const auto pageWidth = renderer.getScreenWidth();
   const auto pageHeight = renderer.getScreenHeight();
+  float cropX = 0, cropY = 0;
 
+  Serial.printf("[%lu] [SLP] bitmap %d x %d, screen %d x %d\n", millis(), bitmap.getWidth(), bitmap.getHeight(),
+                pageWidth, pageHeight);
   if (bitmap.getWidth() > pageWidth || bitmap.getHeight() > pageHeight) {
     // image will scale, make sure placement is right
-    const float ratio = static_cast<float>(bitmap.getWidth()) / static_cast<float>(bitmap.getHeight());
+    float ratio = static_cast<float>(bitmap.getWidth()) / static_cast<float>(bitmap.getHeight());
     const float screenRatio = static_cast<float>(pageWidth) / static_cast<float>(pageHeight);
 
+    Serial.printf("[%lu] [SLP] bitmap ratio: %f, screen ratio: %f\n", millis(), ratio, screenRatio);
     if (ratio > screenRatio) {
       // image wider than viewport ratio, scaled down image needs to be centered vertically
+      if (SETTINGS.sleepScreenCoverMode == CrossPointSettings::SLEEP_SCREEN_COVER_MODE::CROP) {
+        cropX = 1.0f - (screenRatio / ratio);
+        Serial.printf("[%lu] [SLP] Cropping bitmap x: %f\n", millis(), cropX);
+        ratio = (1.0f - cropX) * static_cast<float>(bitmap.getWidth()) / static_cast<float>(bitmap.getHeight());
+      }
       x = 0;
-      y = (pageHeight - pageWidth / ratio) / 2;
+      y = std::round((static_cast<float>(pageHeight) - static_cast<float>(pageWidth) / ratio) / 2);
+      Serial.printf("[%lu] [SLP] Centering with ratio %f to y=%d\n", millis(), ratio, y);
     } else {
       // image taller than viewport ratio, scaled down image needs to be centered horizontally
-      x = (pageWidth - pageHeight * ratio) / 2;
+      if (SETTINGS.sleepScreenCoverMode == CrossPointSettings::SLEEP_SCREEN_COVER_MODE::CROP) {
+        cropY = 1.0f - (ratio / screenRatio);
+        Serial.printf("[%lu] [SLP] Cropping bitmap y: %f\n", millis(), cropY);
+        ratio = static_cast<float>(bitmap.getWidth()) / ((1.0f - cropY) * static_cast<float>(bitmap.getHeight()));
+      }
+      x = std::round((pageWidth - pageHeight * ratio) / 2);
       y = 0;
+      Serial.printf("[%lu] [SLP] Centering with ratio %f to x=%d\n", millis(), ratio, x);
     }
   } else {
     // center the image
@@ -165,21 +170,22 @@ void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
     y = (pageHeight - bitmap.getHeight()) / 2;
   }
 
+  Serial.printf("[%lu] [SLP] drawing to %d x %d\n", millis(), x, y);
   renderer.clearScreen();
-  renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight);
+  renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight, cropX, cropY);
   renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
 
   if (bitmap.hasGreyscale()) {
     bitmap.rewindToData();
     renderer.clearScreen(0x00);
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
-    renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight);
+    renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight, cropX, cropY);
     renderer.copyGrayscaleLsbBuffers();
 
     bitmap.rewindToData();
     renderer.clearScreen(0x00);
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_MSB);
-    renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight);
+    renderer.drawBitmap(bitmap, x, y, pageWidth, pageHeight, cropX, cropY);
     renderer.copyGrayscaleMsbBuffers();
 
     renderer.displayGrayBuffer();
@@ -193,9 +199,10 @@ void SleepActivity::renderCoverSleepScreen() const {
   }
 
   std::string coverBmpPath;
+  bool cropped = SETTINGS.sleepScreenCoverMode == CrossPointSettings::SLEEP_SCREEN_COVER_MODE::CROP;
 
-  // Check if the current book is XTC or EPUB
+  if (StringUtils::checkFileExtension(APP_STATE.openEpubPath, ".xtc") ||
-  if (isXtcFile(APP_STATE.openEpubPath)) {
+      StringUtils::checkFileExtension(APP_STATE.openEpubPath, ".xtch")) {
     // Handle XTC file
     Xtc lastXtc(APP_STATE.openEpubPath, "/.crosspoint");
     if (!lastXtc.load()) {
@@ -209,7 +216,7 @@ void SleepActivity::renderCoverSleepScreen() const {
     }
 
     coverBmpPath = lastXtc.getCoverBmpPath();
-  } else {
+  } else if (StringUtils::checkFileExtension(APP_STATE.openEpubPath, ".epub")) {
     // Handle EPUB file
     Epub lastEpub(APP_STATE.openEpubPath, "/.crosspoint");
     if (!lastEpub.load()) {
@@ -217,12 +224,14 @@ void SleepActivity::renderCoverSleepScreen() const {
       return renderDefaultSleepScreen();
     }
 
-    if (!lastEpub.generateCoverBmp()) {
+    if (!lastEpub.generateCoverBmp(cropped)) {
       Serial.println("[SLP] Failed to generate cover bmp");
       return renderDefaultSleepScreen();
     }
 
-    coverBmpPath = lastEpub.getCoverBmpPath();
+    coverBmpPath = lastEpub.getCoverBmpPath(cropped);
+  } else {
+    return renderDefaultSleepScreen();
   }
 
   FsFile file;
@@ -236,3 +245,8 @@ void SleepActivity::renderCoverSleepScreen() const {
 
   renderDefaultSleepScreen();
 }
+
+void SleepActivity::renderBlankSleepScreen() const {
+  renderer.clearScreen();
+  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+}

src/activities/boot_sleep/SleepActivity.h

@@ -15,4 +15,5 @@ class SleepActivity final : public Activity {
   void renderCustomSleepScreen() const;
   void renderCoverSleepScreen() const;
   void renderBitmapSleepScreen(const Bitmap& bitmap) const;
+  void renderBlankSleepScreen() const;
 };

src/activities/browser/OpdsBookBrowserActivity.cpp

@@ -0,0 +1,408 @@
+#include "OpdsBookBrowserActivity.h"
+
+#include <GfxRenderer.h>
+#include <HardwareSerial.h>
+#include <WiFi.h>
+
+#include "CrossPointSettings.h"
+#include "MappedInputManager.h"
+#include "ScreenComponents.h"
+#include "activities/network/WifiSelectionActivity.h"
+#include "fontIds.h"
+#include "network/HttpDownloader.h"
+#include "util/StringUtils.h"
+#include "util/UrlUtils.h"
+
+namespace {
+constexpr int PAGE_ITEMS = 23;
+constexpr int SKIP_PAGE_MS = 700;
+constexpr char OPDS_ROOT_PATH[] = "opds";  // No leading slash - relative to server URL
+}  // namespace
+
+void OpdsBookBrowserActivity::taskTrampoline(void* param) {
+  auto* self = static_cast<OpdsBookBrowserActivity*>(param);
+  self->displayTaskLoop();
+}
+
+void OpdsBookBrowserActivity::onEnter() {
+  ActivityWithSubactivity::onEnter();
+
+  renderingMutex = xSemaphoreCreateMutex();
+  state = BrowserState::CHECK_WIFI;
+  entries.clear();
+  navigationHistory.clear();
+  currentPath = OPDS_ROOT_PATH;
+  selectorIndex = 0;
+  errorMessage.clear();
+  statusMessage = "Checking WiFi...";
+  updateRequired = true;
+
+  xTaskCreate(&OpdsBookBrowserActivity::taskTrampoline, "OpdsBookBrowserTask",
+              4096,               // Stack size (larger for HTTP operations)
+              this,               // Parameters
+              1,                  // Priority
+              &displayTaskHandle  // Task handle
+  );
+
+  // Check WiFi and connect if needed, then fetch feed
+  checkAndConnectWifi();
+}
+
+void OpdsBookBrowserActivity::onExit() {
+  ActivityWithSubactivity::onExit();
+
+  // Turn off WiFi when exiting
+  WiFi.mode(WIFI_OFF);
+
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+  if (displayTaskHandle) {
+    vTaskDelete(displayTaskHandle);
+    displayTaskHandle = nullptr;
+  }
+  vSemaphoreDelete(renderingMutex);
+  renderingMutex = nullptr;
+  entries.clear();
+  navigationHistory.clear();
+}
+
+void OpdsBookBrowserActivity::loop() {
+  // Handle WiFi selection subactivity
+  if (state == BrowserState::WIFI_SELECTION) {
+    ActivityWithSubactivity::loop();
+    return;
+  }
+
+  // Handle error state - Confirm retries, Back goes back or home
+  if (state == BrowserState::ERROR) {
+    if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
+      // Check if WiFi is still connected
+      if (WiFi.status() == WL_CONNECTED && WiFi.localIP() != IPAddress(0, 0, 0, 0)) {
+        // WiFi connected - just retry fetching the feed
+        Serial.printf("[%lu] [OPDS] Retry: WiFi connected, retrying fetch\n", millis());
+        state = BrowserState::LOADING;
+        statusMessage = "Loading...";
+        updateRequired = true;
+        fetchFeed(currentPath);
+      } else {
+        // WiFi not connected - launch WiFi selection
+        Serial.printf("[%lu] [OPDS] Retry: WiFi not connected, launching selection\n", millis());
+        launchWifiSelection();
+      }
+    } else if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
+      navigateBack();
+    }
+    return;
+  }
+
+  // Handle WiFi check state - only Back works
+  if (state == BrowserState::CHECK_WIFI) {
+    if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
+      onGoHome();
+    }
+    return;
+  }
+
+  // Handle loading state - only Back works
+  if (state == BrowserState::LOADING) {
+    if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
+      navigateBack();
+    }
+    return;
+  }
+
+  // Handle downloading state - no input allowed
+  if (state == BrowserState::DOWNLOADING) {
+    return;
+  }
+
+  // Handle browsing state
+  if (state == BrowserState::BROWSING) {
+    const bool prevReleased = mappedInput.wasReleased(MappedInputManager::Button::Up) ||
+                              mappedInput.wasReleased(MappedInputManager::Button::Left);
+    const bool nextReleased = mappedInput.wasReleased(MappedInputManager::Button::Down) ||
+                              mappedInput.wasReleased(MappedInputManager::Button::Right);
+    const bool skipPage = mappedInput.getHeldTime() > SKIP_PAGE_MS;
+
+    if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
+      if (!entries.empty()) {
+        const auto& entry = entries[selectorIndex];
+        if (entry.type == OpdsEntryType::BOOK) {
+          downloadBook(entry);
+        } else {
+          navigateToEntry(entry);
+        }
+      }
+    } else if (mappedInput.wasReleased(MappedInputManager::Button::Back)) {
+      navigateBack();
+    } else if (prevReleased && !entries.empty()) {
+      if (skipPage) {
+        selectorIndex = ((selectorIndex / PAGE_ITEMS - 1) * PAGE_ITEMS + entries.size()) % entries.size();
+      } else {
+        selectorIndex = (selectorIndex + entries.size() - 1) % entries.size();
+      }
+      updateRequired = true;
+    } else if (nextReleased && !entries.empty()) {
+      if (skipPage) {
+        selectorIndex = ((selectorIndex / PAGE_ITEMS + 1) * PAGE_ITEMS) % entries.size();
+      } else {
+        selectorIndex = (selectorIndex + 1) % entries.size();
+      }
+      updateRequired = true;
+    }
+  }
+}
+
+void OpdsBookBrowserActivity::displayTaskLoop() {
+  while (true) {
+    if (updateRequired) {
+      updateRequired = false;
+      xSemaphoreTake(renderingMutex, portMAX_DELAY);
+      render();
+      xSemaphoreGive(renderingMutex);
+    }
+    vTaskDelay(10 / portTICK_PERIOD_MS);
+  }
+}
+
+void OpdsBookBrowserActivity::render() const {
+  renderer.clearScreen();
+
+  const auto pageWidth = renderer.getScreenWidth();
+  const auto pageHeight = renderer.getScreenHeight();
+
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Calibre Library", true, EpdFontFamily::BOLD);
+
+  if (state == BrowserState::CHECK_WIFI) {
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2, statusMessage.c_str());
+    const auto labels = mappedInput.mapLabels("« Back", "", "", "");
+    renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+    renderer.displayBuffer();
+    return;
+  }
+
+  if (state == BrowserState::LOADING) {
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2, statusMessage.c_str());
+    const auto labels = mappedInput.mapLabels("« Back", "", "", "");
+    renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+    renderer.displayBuffer();
+    return;
+  }
+
+  if (state == BrowserState::ERROR) {
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 - 20, "Error:");
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 + 10, errorMessage.c_str());
+    const auto labels = mappedInput.mapLabels("« Back", "Retry", "", "");
+    renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+    renderer.displayBuffer();
+    return;
+  }
+
+  if (state == BrowserState::DOWNLOADING) {
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 - 40, "Downloading...");
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2 - 10, statusMessage.c_str());
+    if (downloadTotal > 0) {
+      const int barWidth = pageWidth - 100;
+      constexpr int barHeight = 20;
+      constexpr int barX = 50;
+      const int barY = pageHeight / 2 + 20;
+      ScreenComponents::drawProgressBar(renderer, barX, barY, barWidth, barHeight, downloadProgress, downloadTotal);
+    }
+    renderer.displayBuffer();
+    return;
+  }
+
+  // Browsing state
+  // Show appropriate button hint based on selected entry type
+  const char* confirmLabel = "Open";
+  if (!entries.empty() && entries[selectorIndex].type == OpdsEntryType::BOOK) {
+    confirmLabel = "Download";
+  }
+  const auto labels = mappedInput.mapLabels("« Back", confirmLabel, "", "");
+  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+
+  if (entries.empty()) {
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight / 2, "No entries found");
+    renderer.displayBuffer();
+    return;
+  }
+
+  const auto pageStartIndex = selectorIndex / PAGE_ITEMS * PAGE_ITEMS;
+  renderer.fillRect(0, 60 + (selectorIndex % PAGE_ITEMS) * 30 - 2, pageWidth - 1, 30);
+
+  for (size_t i = pageStartIndex; i < entries.size() && i < static_cast<size_t>(pageStartIndex + PAGE_ITEMS); i++) {
+    const auto& entry = entries[i];
+
+    // Format display text with type indicator
+    std::string displayText;
+    if (entry.type == OpdsEntryType::NAVIGATION) {
+      displayText = "> " + entry.title;  // Folder/navigation indicator
+    } else {
+      // Book: "Title - Author" or just "Title"
+      displayText = entry.title;
+      if (!entry.author.empty()) {
+        displayText += " - " + entry.author;
+      }
+    }
+
+    auto item = renderer.truncatedText(UI_10_FONT_ID, displayText.c_str(), renderer.getScreenWidth() - 40);
+    renderer.drawText(UI_10_FONT_ID, 20, 60 + (i % PAGE_ITEMS) * 30, item.c_str(),
+                      i != static_cast<size_t>(selectorIndex));
+  }
+
+  renderer.displayBuffer();
+}
+
+void OpdsBookBrowserActivity::fetchFeed(const std::string& path) {
+  const char* serverUrl = SETTINGS.opdsServerUrl;
+  if (strlen(serverUrl) == 0) {
+    state = BrowserState::ERROR;
+    errorMessage = "No server URL configured";
+    updateRequired = true;
+    return;
+  }
+
+  std::string url = UrlUtils::buildUrl(serverUrl, path);
+  Serial.printf("[%lu] [OPDS] Fetching: %s\n", millis(), url.c_str());
+
+  std::string content;
+  if (!HttpDownloader::fetchUrl(url, content)) {
+    state = BrowserState::ERROR;
+    errorMessage = "Failed to fetch feed";
+    updateRequired = true;
+    return;
+  }
+
+  OpdsParser parser;
+  if (!parser.parse(content.c_str(), content.size())) {
+    state = BrowserState::ERROR;
+    errorMessage = "Failed to parse feed";
+    updateRequired = true;
+    return;
+  }
+
+  entries = parser.getEntries();
+  selectorIndex = 0;
+
+  if (entries.empty()) {
+    state = BrowserState::ERROR;
+    errorMessage = "No entries found";
+    updateRequired = true;
+    return;
+  }
+
+  state = BrowserState::BROWSING;
+  updateRequired = true;
+}
+
+void OpdsBookBrowserActivity::navigateToEntry(const OpdsEntry& entry) {
+  // Push current path to history before navigating
+  navigationHistory.push_back(currentPath);
+  currentPath = entry.href;
+
+  state = BrowserState::LOADING;
+  statusMessage = "Loading...";
+  entries.clear();
+  selectorIndex = 0;
+  updateRequired = true;
+
+  fetchFeed(currentPath);
+}
+
+void OpdsBookBrowserActivity::navigateBack() {
+  if (navigationHistory.empty()) {
+    // At root, go home
+    onGoHome();
+  } else {
+    // Go back to previous catalog
+    currentPath = navigationHistory.back();
+    navigationHistory.pop_back();
+
+    state = BrowserState::LOADING;
+    statusMessage = "Loading...";
+    entries.clear();
+    selectorIndex = 0;
+    updateRequired = true;
+
+    fetchFeed(currentPath);
+  }
+}
+
+void OpdsBookBrowserActivity::downloadBook(const OpdsEntry& book) {
+  state = BrowserState::DOWNLOADING;
+  statusMessage = book.title;
+  downloadProgress = 0;
+  downloadTotal = 0;
+  updateRequired = true;
+
+  // Build full download URL
+  std::string downloadUrl = UrlUtils::buildUrl(SETTINGS.opdsServerUrl, book.href);
+
+  // Create sanitized filename: "Title - Author.epub" or just "Title.epub" if no author
+  std::string baseName = book.title;
+  if (!book.author.empty()) {
+    baseName += " - " + book.author;
+  }
+  std::string filename = "/" + StringUtils::sanitizeFilename(baseName) + ".epub";
+
+  Serial.printf("[%lu] [OPDS] Downloading: %s -> %s\n", millis(), downloadUrl.c_str(), filename.c_str());
+
+  const auto result =
+      HttpDownloader::downloadToFile(downloadUrl, filename, [this](const size_t downloaded, const size_t total) {
+        downloadProgress = downloaded;
+        downloadTotal = total;
+        updateRequired = true;
+      });
+
+  if (result == HttpDownloader::OK) {
+    Serial.printf("[%lu] [OPDS] Download complete: %s\n", millis(), filename.c_str());
+    state = BrowserState::BROWSING;
+    updateRequired = true;
+  } else {
+    state = BrowserState::ERROR;
+    errorMessage = "Download failed";
+    updateRequired = true;
+  }
+}
+
+void OpdsBookBrowserActivity::checkAndConnectWifi() {
+  // Already connected? Verify connection is valid by checking IP
+  if (WiFi.status() == WL_CONNECTED && WiFi.localIP() != IPAddress(0, 0, 0, 0)) {
+    state = BrowserState::LOADING;
+    statusMessage = "Loading...";
+    updateRequired = true;
+    fetchFeed(currentPath);
+    return;
+  }
+
+  // Not connected - launch WiFi selection screen directly
+  launchWifiSelection();
+}
+
+void OpdsBookBrowserActivity::launchWifiSelection() {
+  state = BrowserState::WIFI_SELECTION;
+  updateRequired = true;
+
+  enterNewActivity(new WifiSelectionActivity(renderer, mappedInput,
+                                             [this](const bool connected) { onWifiSelectionComplete(connected); }));
+}
+
+void OpdsBookBrowserActivity::onWifiSelectionComplete(const bool connected) {
+  exitActivity();
+
+  if (connected) {
+    Serial.printf("[%lu] [OPDS] WiFi connected via selection, fetching feed\n", millis());
+    state = BrowserState::LOADING;
+    statusMessage = "Loading...";
+    updateRequired = true;
+    fetchFeed(currentPath);
+  } else {
+    Serial.printf("[%lu] [OPDS] WiFi selection cancelled/failed\n", millis());
+    // Force disconnect to ensure clean state for next retry
+    // This prevents stale connection status from interfering
+    WiFi.disconnect();
+    WiFi.mode(WIFI_OFF);
+    state = BrowserState::ERROR;
+    errorMessage = "WiFi connection failed";
+    updateRequired = true;
+  }
+}

src/activities/browser/OpdsBookBrowserActivity.h

@@ -0,0 +1,65 @@
+#pragma once
+#include <OpdsParser.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <functional>
+#include <string>
+#include <vector>
+
+#include "../ActivityWithSubactivity.h"
+
+/**
+ * Activity for browsing and downloading books from an OPDS server.
+ * Supports navigation through catalog hierarchy and downloading EPUBs.
+ * When WiFi connection fails, launches WiFi selection to let user connect.
+ */
+class OpdsBookBrowserActivity final : public ActivityWithSubactivity {
+ public:
+  enum class BrowserState {
+    CHECK_WIFI,      // Checking WiFi connection
+    WIFI_SELECTION,  // WiFi selection subactivity is active
+    LOADING,         // Fetching OPDS feed
+    BROWSING,        // Displaying entries (navigation or books)
+    DOWNLOADING,     // Downloading selected EPUB
+    ERROR            // Error state with message
+  };
+
+  explicit OpdsBookBrowserActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
+                                   const std::function<void()>& onGoHome)
+      : ActivityWithSubactivity("OpdsBookBrowser", renderer, mappedInput), onGoHome(onGoHome) {}
+
+  void onEnter() override;
+  void onExit() override;
+  void loop() override;
+
+ private:
+  TaskHandle_t displayTaskHandle = nullptr;
+  SemaphoreHandle_t renderingMutex = nullptr;
+  bool updateRequired = false;
+
+  BrowserState state = BrowserState::LOADING;
+  std::vector<OpdsEntry> entries;
+  std::vector<std::string> navigationHistory;  // Stack of previous feed paths for back navigation
+  std::string currentPath;                     // Current feed path being displayed
+  int selectorIndex = 0;
+  std::string errorMessage;
+  std::string statusMessage;
+  size_t downloadProgress = 0;
+  size_t downloadTotal = 0;
+
+  const std::function<void()> onGoHome;
+
+  static void taskTrampoline(void* param);
+  [[noreturn]] void displayTaskLoop();
+  void render() const;
+
+  void checkAndConnectWifi();
+  void launchWifiSelection();
+  void onWifiSelectionComplete(bool connected);
+  void fetchFeed(const std::string& path);
+  void navigateToEntry(const OpdsEntry& entry);
+  void navigateBack();
+  void downloadBook(const OpdsEntry& book);
+};

src/activities/home/HomeActivity.cpp

@@ -4,17 +4,28 @@
 #include <GfxRenderer.h>
 #include <SDCardManager.h>
 
+#include <cstring>
+#include <vector>
+
+#include "Battery.h"
+#include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "MappedInputManager.h"
 #include "ScreenComponents.h"
 #include "fontIds.h"
+#include "util/StringUtils.h"
 
 void HomeActivity::taskTrampoline(void* param) {
   auto* self = static_cast<HomeActivity*>(param);
   self->displayTaskLoop();
 }
 
-int HomeActivity::getMenuItemCount() const { return hasContinueReading ? 4 : 3; }
+int HomeActivity::getMenuItemCount() const {
+  int count = 3;  // Browse files, File transfer, Settings
+  if (hasContinueReading) count++;
+  if (hasOpdsUrl) count++;
+  return count;
+}
 
 void HomeActivity::onEnter() {
   Activity::onEnter();
@@ -24,6 +35,9 @@ void HomeActivity::onEnter() {
   // Check if we have a book to continue reading
   hasContinueReading = !APP_STATE.openEpubPath.empty() && SdMan.exists(APP_STATE.openEpubPath.c_str());
 
+  // Check if OPDS browser URL is configured
+  hasOpdsUrl = strlen(SETTINGS.opdsServerUrl) > 0;
+
   if (hasContinueReading) {
     // Extract filename from path for display
     lastBookTitle = APP_STATE.openEpubPath;
@@ -32,10 +46,8 @@ void HomeActivity::onEnter() {
       lastBookTitle = lastBookTitle.substr(lastSlash + 1);
     }
 
-    const std::string ext4 = lastBookTitle.length() >= 4 ? lastBookTitle.substr(lastBookTitle.length() - 4) : "";
-    const std::string ext5 = lastBookTitle.length() >= 5 ? lastBookTitle.substr(lastBookTitle.length() - 5) : "";
     // If epub, try to load the metadata for title/author
-    if (ext5 == ".epub") {
+    if (StringUtils::checkFileExtension(lastBookTitle, ".epub")) {
       Epub epub(APP_STATE.openEpubPath, "/.crosspoint");
       epub.load(false);
       if (!epub.getTitle().empty()) {
@@ -44,9 +56,9 @@ void HomeActivity::onEnter() {
       if (!epub.getAuthor().empty()) {
         lastBookAuthor = std::string(epub.getAuthor());
       }
-    } else if (ext5 == ".xtch") {
+    } else if (StringUtils::checkFileExtension(lastBookTitle, ".xtch")) {
       lastBookTitle.resize(lastBookTitle.length() - 5);
-    } else if (ext4 == ".xtc") {
+    } else if (StringUtils::checkFileExtension(lastBookTitle, ".xtc")) {
       lastBookTitle.resize(lastBookTitle.length() - 4);
     }
   }
@@ -86,27 +98,25 @@ void HomeActivity::loop() {
   const int menuCount = getMenuItemCount();
 
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
-    if (hasContinueReading) {
+    // Calculate dynamic indices based on which options are available
-      // Menu: Continue Reading, Browse, File transfer, Settings
+    int idx = 0;
-      if (selectorIndex == 0) {
+    const int continueIdx = hasContinueReading ? idx++ : -1;
+    const int browseFilesIdx = idx++;
+    const int opdsLibraryIdx = hasOpdsUrl ? idx++ : -1;
+    const int fileTransferIdx = idx++;
+    const int settingsIdx = idx;
+
+    if (selectorIndex == continueIdx) {
       onContinueReading();
-      } else if (selectorIndex == 1) {
+    } else if (selectorIndex == browseFilesIdx) {
       onReaderOpen();
-      } else if (selectorIndex == 2) {
+    } else if (selectorIndex == opdsLibraryIdx) {
+      onOpdsBrowserOpen();
+    } else if (selectorIndex == fileTransferIdx) {
       onFileTransferOpen();
-      } else if (selectorIndex == 3) {
+    } else if (selectorIndex == settingsIdx) {
       onSettingsOpen();
     }
-    } else {
-      // Menu: Browse, File transfer, Settings
-      if (selectorIndex == 0) {
-        onReaderOpen();
-      } else if (selectorIndex == 1) {
-        onFileTransferOpen();
-      } else if (selectorIndex == 2) {
-        onSettingsOpen();
-      }
-    }
   } else if (prevPressed) {
     selectorIndex = (selectorIndex + menuCount - 1) % menuCount;
     updateRequired = true;
@@ -277,24 +287,31 @@ void HomeActivity::render() const {
     renderer.drawCenteredText(UI_10_FONT_ID, y + renderer.getLineHeight(UI_12_FONT_ID), "Start reading below");
   }
 
-  // --- Bottom menu tiles (indices 1-3) ---
+  // --- Bottom menu tiles ---
-  const int menuTileWidth = pageWidth - 2 * margin;
+  // Build menu items dynamically
-  constexpr int menuTileHeight = 50;
+  std::vector<const char*> menuItems = {"Browse Files", "File Transfer", "Settings"};
-  constexpr int menuSpacing = 10;
+  if (hasOpdsUrl) {
-  constexpr int totalMenuHeight = 3 * menuTileHeight + 2 * menuSpacing;
+    // Insert Calibre Library after Browse Files
+    menuItems.insert(menuItems.begin() + 1, "Calibre Library");
+  }
 
-  int menuStartY = bookY + bookHeight + 20;
+  const int menuTileWidth = pageWidth - 2 * margin;
+  constexpr int menuTileHeight = 45;
+  constexpr int menuSpacing = 8;
+  const int totalMenuHeight =
+      static_cast<int>(menuItems.size()) * menuTileHeight + (static_cast<int>(menuItems.size()) - 1) * menuSpacing;
+
+  int menuStartY = bookY + bookHeight + 15;
   // Ensure we don't collide with the bottom button legend
   const int maxMenuStartY = pageHeight - bottomMargin - totalMenuHeight - margin;
   if (menuStartY > maxMenuStartY) {
     menuStartY = maxMenuStartY;
   }
 
-  for (int i = 0; i < 3; ++i) {
+  for (size_t i = 0; i < menuItems.size(); ++i) {
-    constexpr const char* items[3] = {"Browse files", "File transfer", "Settings"};
+    const int overallIndex = static_cast<int>(i) + (hasContinueReading ? 1 : 0);
-    const int overallIndex = i + (getMenuItemCount() - 3);
     constexpr int tileX = margin;
-    const int tileY = menuStartY + i * (menuTileHeight + menuSpacing);
+    const int tileY = menuStartY + static_cast<int>(i) * (menuTileHeight + menuSpacing);
     const bool selected = selectorIndex == overallIndex;
 
     if (selected) {
@@ -303,7 +320,7 @@ void HomeActivity::render() const {
       renderer.drawRect(tileX, tileY, menuTileWidth, menuTileHeight);
     }
 
-    const char* label = items[i];
+    const char* label = menuItems[i];
     const int textWidth = renderer.getTextWidth(UI_10_FONT_ID, label);
     const int textX = tileX + (menuTileWidth - textWidth) / 2;
     const int lineHeight = renderer.getLineHeight(UI_10_FONT_ID);
@@ -316,7 +333,13 @@ void HomeActivity::render() const {
   const auto labels = mappedInput.mapLabels("", "Confirm", "Up", "Down");
   renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
 
-  ScreenComponents::drawBattery(renderer, 20, pageHeight - 70);
+  const bool showBatteryPercentage =
+      SETTINGS.hideBatteryPercentage != CrossPointSettings::HIDE_BATTERY_PERCENTAGE::HIDE_ALWAYS;
+  // get percentage so we can align text properly
+  const uint16_t percentage = battery.readPercentage();
+  const auto percentageText = showBatteryPercentage ? std::to_string(percentage) + "%" : "";
+  const auto batteryX = pageWidth - 25 - renderer.getTextWidth(SMALL_FONT_ID, percentageText.c_str());
+  ScreenComponents::drawBattery(renderer, batteryX, 10, showBatteryPercentage);
 
   renderer.displayBuffer();
 }

src/activities/home/HomeActivity.h

@@ -13,12 +13,14 @@ class HomeActivity final : public Activity {
   int selectorIndex = 0;
   bool updateRequired = false;
   bool hasContinueReading = false;
+  bool hasOpdsUrl = false;
   std::string lastBookTitle;
   std::string lastBookAuthor;
   const std::function<void()> onContinueReading;
   const std::function<void()> onReaderOpen;
   const std::function<void()> onSettingsOpen;
   const std::function<void()> onFileTransferOpen;
+  const std::function<void()> onOpdsBrowserOpen;
 
   static void taskTrampoline(void* param);
   [[noreturn]] void displayTaskLoop();
@@ -28,12 +30,14 @@ class HomeActivity final : public Activity {
  public:
   explicit HomeActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
                         const std::function<void()>& onContinueReading, const std::function<void()>& onReaderOpen,
-                        const std::function<void()>& onSettingsOpen, const std::function<void()>& onFileTransferOpen)
+                        const std::function<void()>& onSettingsOpen, const std::function<void()>& onFileTransferOpen,
+                        const std::function<void()>& onOpdsBrowserOpen)
       : Activity("Home", renderer, mappedInput),
         onContinueReading(onContinueReading),
         onReaderOpen(onReaderOpen),
         onSettingsOpen(onSettingsOpen),
-        onFileTransferOpen(onFileTransferOpen) {}
+        onFileTransferOpen(onFileTransferOpen),
+        onOpdsBrowserOpen(onOpdsBrowserOpen) {}
   void onEnter() override;
   void onExit() override;
   void loop() override;

src/activities/network/CalibreWirelessActivity.cpp

@@ -0,0 +1,756 @@
+#include "CalibreWirelessActivity.h"
+
+#include <GfxRenderer.h>
+#include <HardwareSerial.h>
+#include <SDCardManager.h>
+#include <WiFi.h>
+
+#include <cstring>
+
+#include "MappedInputManager.h"
+#include "ScreenComponents.h"
+#include "fontIds.h"
+#include "util/StringUtils.h"
+
+namespace {
+constexpr uint16_t UDP_PORTS[] = {54982, 48123, 39001, 44044, 59678};
+constexpr uint16_t LOCAL_UDP_PORT = 8134;  // Port to receive responses
+}  // namespace
+
+void CalibreWirelessActivity::displayTaskTrampoline(void* param) {
+  auto* self = static_cast<CalibreWirelessActivity*>(param);
+  self->displayTaskLoop();
+}
+
+void CalibreWirelessActivity::networkTaskTrampoline(void* param) {
+  auto* self = static_cast<CalibreWirelessActivity*>(param);
+  self->networkTaskLoop();
+}
+
+void CalibreWirelessActivity::onEnter() {
+  Activity::onEnter();
+
+  renderingMutex = xSemaphoreCreateMutex();
+  stateMutex = xSemaphoreCreateMutex();
+
+  state = WirelessState::DISCOVERING;
+  statusMessage = "Discovering Calibre...";
+  errorMessage.clear();
+  calibreHostname.clear();
+  calibreHost.clear();
+  calibrePort = 0;
+  calibreAltPort = 0;
+  currentFilename.clear();
+  currentFileSize = 0;
+  bytesReceived = 0;
+  inBinaryMode = false;
+  recvBuffer.clear();
+
+  updateRequired = true;
+
+  // Start UDP listener for Calibre responses
+  udp.begin(LOCAL_UDP_PORT);
+
+  // Create display task
+  xTaskCreate(&CalibreWirelessActivity::displayTaskTrampoline, "CalDisplayTask", 2048, this, 1, &displayTaskHandle);
+
+  // Create network task with larger stack for JSON parsing
+  xTaskCreate(&CalibreWirelessActivity::networkTaskTrampoline, "CalNetworkTask", 12288, this, 2, &networkTaskHandle);
+}
+
+void CalibreWirelessActivity::onExit() {
+  Activity::onExit();
+
+  // Turn off WiFi when exiting
+  WiFi.mode(WIFI_OFF);
+
+  // Stop UDP listening
+  udp.stop();
+
+  // Close TCP client if connected
+  if (tcpClient.connected()) {
+    tcpClient.stop();
+  }
+
+  // Close any open file
+  if (currentFile) {
+    currentFile.close();
+  }
+
+  // Acquire stateMutex before deleting network task to avoid race condition
+  xSemaphoreTake(stateMutex, portMAX_DELAY);
+  if (networkTaskHandle) {
+    vTaskDelete(networkTaskHandle);
+    networkTaskHandle = nullptr;
+  }
+  xSemaphoreGive(stateMutex);
+
+  // Acquire renderingMutex before deleting display task
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+  if (displayTaskHandle) {
+    vTaskDelete(displayTaskHandle);
+    displayTaskHandle = nullptr;
+  }
+  vSemaphoreDelete(renderingMutex);
+  renderingMutex = nullptr;
+
+  vSemaphoreDelete(stateMutex);
+  stateMutex = nullptr;
+}
+
+void CalibreWirelessActivity::loop() {
+  if (mappedInput.wasPressed(MappedInputManager::Button::Back)) {
+    onComplete();
+    return;
+  }
+}
+
+void CalibreWirelessActivity::displayTaskLoop() {
+  while (true) {
+    if (updateRequired) {
+      updateRequired = false;
+      xSemaphoreTake(renderingMutex, portMAX_DELAY);
+      render();
+      xSemaphoreGive(renderingMutex);
+    }
+    vTaskDelay(50 / portTICK_PERIOD_MS);
+  }
+}
+
+void CalibreWirelessActivity::networkTaskLoop() {
+  while (true) {
+    xSemaphoreTake(stateMutex, portMAX_DELAY);
+    const auto currentState = state;
+    xSemaphoreGive(stateMutex);
+
+    switch (currentState) {
+      case WirelessState::DISCOVERING:
+        listenForDiscovery();
+        break;
+
+      case WirelessState::CONNECTING:
+      case WirelessState::WAITING:
+      case WirelessState::RECEIVING:
+        handleTcpClient();
+        break;
+
+      case WirelessState::COMPLETE:
+      case WirelessState::DISCONNECTED:
+      case WirelessState::ERROR:
+        // Just wait, user will exit
+        vTaskDelay(100 / portTICK_PERIOD_MS);
+        break;
+    }
+
+    vTaskDelay(10 / portTICK_PERIOD_MS);
+  }
+}
+
+void CalibreWirelessActivity::listenForDiscovery() {
+  // Broadcast "hello" on all UDP discovery ports to find Calibre
+  for (const uint16_t port : UDP_PORTS) {
+    udp.beginPacket("255.255.255.255", port);
+    udp.write(reinterpret_cast<const uint8_t*>("hello"), 5);
+    udp.endPacket();
+  }
+
+  // Wait for Calibre's response
+  vTaskDelay(500 / portTICK_PERIOD_MS);
+
+  // Check for response
+  const int packetSize = udp.parsePacket();
+  if (packetSize > 0) {
+    char buffer[256];
+    const int len = udp.read(buffer, sizeof(buffer) - 1);
+    if (len > 0) {
+      buffer[len] = '\0';
+
+      // Parse Calibre's response format:
+      // "calibre wireless device client (on hostname);port,content_server_port"
+      // or just the hostname and port info
+      std::string response(buffer);
+
+      // Try to extract host and port
+      // Format: "calibre wireless device client (on HOSTNAME);PORT,..."
+      size_t onPos = response.find("(on ");
+      size_t closePos = response.find(')');
+      size_t semiPos = response.find(';');
+      size_t commaPos = response.find(',', semiPos);
+
+      if (semiPos != std::string::npos) {
+        // Get ports after semicolon (format: "port1,port2")
+        std::string portStr;
+        if (commaPos != std::string::npos && commaPos > semiPos) {
+          portStr = response.substr(semiPos + 1, commaPos - semiPos - 1);
+          // Get alternative port after comma
+          std::string altPortStr = response.substr(commaPos + 1);
+          // Trim whitespace and non-digits from alt port
+          size_t altEnd = 0;
+          while (altEnd < altPortStr.size() && altPortStr[altEnd] >= '0' && altPortStr[altEnd] <= '9') {
+            altEnd++;
+          }
+          if (altEnd > 0) {
+            calibreAltPort = static_cast<uint16_t>(std::stoi(altPortStr.substr(0, altEnd)));
+          }
+        } else {
+          portStr = response.substr(semiPos + 1);
+        }
+
+        // Trim whitespace from main port
+        while (!portStr.empty() && (portStr[0] == ' ' || portStr[0] == '\t')) {
+          portStr = portStr.substr(1);
+        }
+
+        if (!portStr.empty()) {
+          calibrePort = static_cast<uint16_t>(std::stoi(portStr));
+        }
+
+        // Get hostname if present, otherwise use sender IP
+        if (onPos != std::string::npos && closePos != std::string::npos && closePos > onPos + 4) {
+          calibreHostname = response.substr(onPos + 4, closePos - onPos - 4);
+        }
+      }
+
+      // Use the sender's IP as the host to connect to
+      calibreHost = udp.remoteIP().toString().c_str();
+      if (calibreHostname.empty()) {
+        calibreHostname = calibreHost;
+      }
+
+      if (calibrePort > 0) {
+        // Connect to Calibre's TCP server - try main port first, then alt port
+        setState(WirelessState::CONNECTING);
+        setStatus("Connecting to " + calibreHostname + "...");
+
+        // Small delay before connecting
+        vTaskDelay(100 / portTICK_PERIOD_MS);
+
+        bool connected = false;
+
+        // Try main port first
+        if (tcpClient.connect(calibreHost.c_str(), calibrePort, 5000)) {
+          connected = true;
+        }
+
+        // Try alternative port if main failed
+        if (!connected && calibreAltPort > 0) {
+          vTaskDelay(200 / portTICK_PERIOD_MS);
+          if (tcpClient.connect(calibreHost.c_str(), calibreAltPort, 5000)) {
+            connected = true;
+          }
+        }
+
+        if (connected) {
+          setState(WirelessState::WAITING);
+          setStatus("Connected to " + calibreHostname + "\nWaiting for commands...");
+        } else {
+          // Don't set error yet, keep trying discovery
+          setState(WirelessState::DISCOVERING);
+          setStatus("Discovering Calibre...\n(Connection failed, retrying)");
+          calibrePort = 0;
+          calibreAltPort = 0;
+        }
+      }
+    }
+  }
+}
+
+void CalibreWirelessActivity::handleTcpClient() {
+  if (!tcpClient.connected()) {
+    setState(WirelessState::DISCONNECTED);
+    setStatus("Calibre disconnected");
+    return;
+  }
+
+  if (inBinaryMode) {
+    receiveBinaryData();
+    return;
+  }
+
+  std::string message;
+  if (readJsonMessage(message)) {
+    // Parse opcode from JSON array format: [opcode, {...}]
+    // Find the opcode (first number after '[')
+    size_t start = message.find('[');
+    if (start != std::string::npos) {
+      start++;
+      size_t end = message.find(',', start);
+      if (end != std::string::npos) {
+        const int opcodeInt = std::stoi(message.substr(start, end - start));
+        if (opcodeInt < 0 || opcodeInt >= OpCode::ERROR) {
+          Serial.printf("[%lu] [CAL] Invalid opcode: %d\n", millis(), opcodeInt);
+          sendJsonResponse(OpCode::OK, "{}");
+          return;
+        }
+        const auto opcode = static_cast<OpCode>(opcodeInt);
+
+        // Extract data object (everything after the comma until the last ']')
+        size_t dataStart = end + 1;
+        size_t dataEnd = message.rfind(']');
+        std::string data = "";
+        if (dataEnd != std::string::npos && dataEnd > dataStart) {
+          data = message.substr(dataStart, dataEnd - dataStart);
+        }
+
+        handleCommand(opcode, data);
+      }
+    }
+  }
+}
+
+bool CalibreWirelessActivity::readJsonMessage(std::string& message) {
+  // Read available data into buffer
+  int available = tcpClient.available();
+  if (available > 0) {
+    // Limit buffer growth to prevent memory issues
+    if (recvBuffer.size() > 100000) {
+      recvBuffer.clear();
+      return false;
+    }
+    // Read in chunks
+    char buf[1024];
+    while (available > 0) {
+      int toRead = std::min(available, static_cast<int>(sizeof(buf)));
+      int bytesRead = tcpClient.read(reinterpret_cast<uint8_t*>(buf), toRead);
+      if (bytesRead > 0) {
+        recvBuffer.append(buf, bytesRead);
+        available -= bytesRead;
+      } else {
+        break;
+      }
+    }
+  }
+
+  if (recvBuffer.empty()) {
+    return false;
+  }
+
+  // Find '[' which marks the start of JSON
+  size_t bracketPos = recvBuffer.find('[');
+  if (bracketPos == std::string::npos) {
+    // No '[' found - if buffer is getting large, something is wrong
+    if (recvBuffer.size() > 1000) {
+      recvBuffer.clear();
+    }
+    return false;
+  }
+
+  // Try to extract length from digits before '['
+  // Calibre ALWAYS sends a length prefix, so if it's not valid digits, it's garbage
+  size_t msgLen = 0;
+  bool validPrefix = false;
+
+  if (bracketPos > 0 && bracketPos <= 12) {
+    // Check if prefix is all digits
+    bool allDigits = true;
+    for (size_t i = 0; i < bracketPos; i++) {
+      char c = recvBuffer[i];
+      if (c < '0' || c > '9') {
+        allDigits = false;
+        break;
+      }
+    }
+    if (allDigits) {
+      msgLen = std::stoul(recvBuffer.substr(0, bracketPos));
+      validPrefix = true;
+    }
+  }
+
+  if (!validPrefix) {
+    // Not a valid length prefix - discard everything up to '[' and treat '[' as start
+    if (bracketPos > 0) {
+      recvBuffer = recvBuffer.substr(bracketPos);
+    }
+    // Without length prefix, we can't reliably parse - wait for more data
+    // that hopefully starts with a proper length prefix
+    return false;
+  }
+
+  // Sanity check the message length
+  if (msgLen > 1000000) {
+    recvBuffer = recvBuffer.substr(bracketPos + 1);  // Skip past this '[' and try again
+    return false;
+  }
+
+  // Check if we have the complete message
+  size_t totalNeeded = bracketPos + msgLen;
+  if (recvBuffer.size() < totalNeeded) {
+    // Not enough data yet - wait for more
+    return false;
+  }
+
+  // Extract the message
+  message = recvBuffer.substr(bracketPos, msgLen);
+
+  // Keep the rest in buffer (may contain binary data or next message)
+  if (recvBuffer.size() > totalNeeded) {
+    recvBuffer = recvBuffer.substr(totalNeeded);
+  } else {
+    recvBuffer.clear();
+  }
+
+  return true;
+}
+
+void CalibreWirelessActivity::sendJsonResponse(const OpCode opcode, const std::string& data) {
+  // Format: length + [opcode, {data}]
+  std::string json = "[" + std::to_string(opcode) + "," + data + "]";
+  const std::string lengthPrefix = std::to_string(json.length());
+  json.insert(0, lengthPrefix);
+
+  tcpClient.write(reinterpret_cast<const uint8_t*>(json.c_str()), json.length());
+  tcpClient.flush();
+}
+
+void CalibreWirelessActivity::handleCommand(const OpCode opcode, const std::string& data) {
+  switch (opcode) {
+    case OpCode::GET_INITIALIZATION_INFO:
+      handleGetInitializationInfo(data);
+      break;
+    case OpCode::GET_DEVICE_INFORMATION:
+      handleGetDeviceInformation();
+      break;
+    case OpCode::FREE_SPACE:
+      handleFreeSpace();
+      break;
+    case OpCode::GET_BOOK_COUNT:
+      handleGetBookCount();
+      break;
+    case OpCode::SEND_BOOK:
+      handleSendBook(data);
+      break;
+    case OpCode::SEND_BOOK_METADATA:
+      handleSendBookMetadata(data);
+      break;
+    case OpCode::DISPLAY_MESSAGE:
+      handleDisplayMessage(data);
+      break;
+    case OpCode::NOOP:
+      handleNoop(data);
+      break;
+    case OpCode::SET_CALIBRE_DEVICE_INFO:
+    case OpCode::SET_CALIBRE_DEVICE_NAME:
+      // These set metadata about the connected Calibre instance.
+      // We don't need this info, just acknowledge receipt.
+      sendJsonResponse(OpCode::OK, "{}");
+      break;
+    case OpCode::SET_LIBRARY_INFO:
+      // Library metadata (name, UUID) - not needed for receiving books
+      sendJsonResponse(OpCode::OK, "{}");
+      break;
+    case OpCode::SEND_BOOKLISTS:
+      // Calibre asking us to send our book list. We report 0 books in
+      // handleGetBookCount, so this is effectively a no-op.
+      sendJsonResponse(OpCode::OK, "{}");
+      break;
+    case OpCode::TOTAL_SPACE:
+      handleFreeSpace();
+      break;
+    default:
+      Serial.printf("[%lu] [CAL] Unknown opcode: %d\n", millis(), opcode);
+      sendJsonResponse(OpCode::OK, "{}");
+      break;
+  }
+}
+
+void CalibreWirelessActivity::handleGetInitializationInfo(const std::string& data) {
+  setState(WirelessState::WAITING);
+  setStatus("Connected to " + calibreHostname +
+            "\nWaiting for transfer...\n\nIf transfer fails, enable\n'Ignore free space' in Calibre's\nSmartDevice "
+            "plugin settings.");
+
+  // Build response with device capabilities
+  // Format must match what Calibre expects from a smart device
+  std::string response = "{";
+  response += "\"appName\":\"CrossPoint\",";
+  response += "\"acceptedExtensions\":[\"epub\"],";
+  response += "\"cacheUsesLpaths\":true,";
+  response += "\"canAcceptLibraryInfo\":true,";
+  response += "\"canDeleteMultipleBooks\":true,";
+  response += "\"canReceiveBookBinary\":true,";
+  response += "\"canSendOkToSendbook\":true,";
+  response += "\"canStreamBooks\":true,";
+  response += "\"canStreamMetadata\":true,";
+  response += "\"canUseCachedMetadata\":true,";
+  // ccVersionNumber: Calibre Companion protocol version. 212 matches CC 5.4.20+.
+  // Using a known version ensures compatibility with Calibre's feature detection.
+  response += "\"ccVersionNumber\":212,";
+  // coverHeight: Max cover image height. We don't process covers, so this is informational only.
+  response += "\"coverHeight\":800,";
+  response += "\"deviceKind\":\"CrossPoint\",";
+  response += "\"deviceName\":\"CrossPoint\",";
+  response += "\"extensionPathLengths\":{\"epub\":37},";
+  response += "\"maxBookContentPacketLen\":4096,";
+  response += "\"passwordHash\":\"\",";
+  response += "\"useUuidFileNames\":false,";
+  response += "\"versionOK\":true";
+  response += "}";
+
+  sendJsonResponse(OpCode::OK, response);
+}
+
+void CalibreWirelessActivity::handleGetDeviceInformation() {
+  std::string response = "{";
+  response += "\"device_info\":{";
+  response += "\"device_store_uuid\":\"" + getDeviceUuid() + "\",";
+  response += "\"device_name\":\"CrossPoint Reader\",";
+  response += "\"device_version\":\"" CROSSPOINT_VERSION "\"";
+  response += "},";
+  response += "\"version\":1,";
+  response += "\"device_version\":\"" CROSSPOINT_VERSION "\"";
+  response += "}";
+
+  sendJsonResponse(OpCode::OK, response);
+}
+
+void CalibreWirelessActivity::handleFreeSpace() {
+  // TODO: Report actual SD card free space instead of hardcoded value
+  // Report 10GB free space for now
+  sendJsonResponse(OpCode::OK, "{\"free_space_on_device\":10737418240}");
+}
+
+void CalibreWirelessActivity::handleGetBookCount() {
+  // We report 0 books - Calibre will send books without checking for duplicates
+  std::string response = "{\"count\":0,\"willStream\":true,\"willScan\":false}";
+  sendJsonResponse(OpCode::OK, response);
+}
+
+void CalibreWirelessActivity::handleSendBook(const std::string& data) {
+  // Manually extract lpath and length from SEND_BOOK data
+  // Full JSON parsing crashes on large metadata, so we just extract what we need
+
+  // Extract "lpath" field - format: "lpath": "value"
+  std::string lpath;
+  size_t lpathPos = data.find("\"lpath\"");
+  if (lpathPos != std::string::npos) {
+    size_t colonPos = data.find(':', lpathPos + 7);
+    if (colonPos != std::string::npos) {
+      size_t quoteStart = data.find('"', colonPos + 1);
+      if (quoteStart != std::string::npos) {
+        size_t quoteEnd = data.find('"', quoteStart + 1);
+        if (quoteEnd != std::string::npos) {
+          lpath = data.substr(quoteStart + 1, quoteEnd - quoteStart - 1);
+        }
+      }
+    }
+  }
+
+  // Extract top-level "length" field - must track depth to skip nested objects
+  // The metadata contains nested "length" fields (e.g., cover image length)
+  size_t length = 0;
+  int depth = 0;
+  for (size_t i = 0; i < data.size(); i++) {
+    char c = data[i];
+    if (c == '{' || c == '[') {
+      depth++;
+    } else if (c == '}' || c == ']') {
+      depth--;
+    } else if (depth == 1 && c == '"') {
+      // At top level, check if this is "length"
+      if (i + 9 < data.size() && data.substr(i, 8) == "\"length\"") {
+        // Found top-level "length" - extract the number after ':'
+        size_t colonPos = data.find(':', i + 8);
+        if (colonPos != std::string::npos) {
+          size_t numStart = colonPos + 1;
+          while (numStart < data.size() && (data[numStart] == ' ' || data[numStart] == '\t')) {
+            numStart++;
+          }
+          size_t numEnd = numStart;
+          while (numEnd < data.size() && data[numEnd] >= '0' && data[numEnd] <= '9') {
+            numEnd++;
+          }
+          if (numEnd > numStart) {
+            length = std::stoul(data.substr(numStart, numEnd - numStart));
+            break;
+          }
+        }
+      }
+    }
+  }
+
+  if (lpath.empty() || length == 0) {
+    sendJsonResponse(OpCode::ERROR, "{\"message\":\"Invalid book data\"}");
+    return;
+  }
+
+  // Extract filename from lpath
+  std::string filename = lpath;
+  const size_t lastSlash = filename.rfind('/');
+  if (lastSlash != std::string::npos) {
+    filename = filename.substr(lastSlash + 1);
+  }
+
+  // Sanitize and create full path
+  currentFilename = "/" + StringUtils::sanitizeFilename(filename);
+  if (!StringUtils::checkFileExtension(currentFilename, ".epub")) {
+    currentFilename += ".epub";
+  }
+  currentFileSize = length;
+  bytesReceived = 0;
+
+  setState(WirelessState::RECEIVING);
+  setStatus("Receiving: " + filename);
+
+  // Open file for writing
+  if (!SdMan.openFileForWrite("CAL", currentFilename.c_str(), currentFile)) {
+    setError("Failed to create file");
+    sendJsonResponse(OpCode::ERROR, "{\"message\":\"Failed to create file\"}");
+    return;
+  }
+
+  // Send OK to start receiving binary data
+  sendJsonResponse(OpCode::OK, "{}");
+
+  // Switch to binary mode
+  inBinaryMode = true;
+  binaryBytesRemaining = length;
+
+  // Check if recvBuffer has leftover data (binary file data that arrived with the JSON)
+  if (!recvBuffer.empty()) {
+    size_t toWrite = std::min(recvBuffer.size(), binaryBytesRemaining);
+    size_t written = currentFile.write(reinterpret_cast<const uint8_t*>(recvBuffer.data()), toWrite);
+    bytesReceived += written;
+    binaryBytesRemaining -= written;
+    recvBuffer = recvBuffer.substr(toWrite);
+    updateRequired = true;
+  }
+}
+
+void CalibreWirelessActivity::handleSendBookMetadata(const std::string& data) {
+  // We receive metadata after the book - just acknowledge
+  sendJsonResponse(OpCode::OK, "{}");
+}
+
+void CalibreWirelessActivity::handleDisplayMessage(const std::string& data) {
+  // Calibre may send messages to display
+  // Check messageKind - 1 means password error
+  if (data.find("\"messageKind\":1") != std::string::npos) {
+    setError("Password required");
+  }
+  sendJsonResponse(OpCode::OK, "{}");
+}
+
+void CalibreWirelessActivity::handleNoop(const std::string& data) {
+  // Check for ejecting flag
+  if (data.find("\"ejecting\":true") != std::string::npos) {
+    setState(WirelessState::DISCONNECTED);
+    setStatus("Calibre disconnected");
+  }
+  sendJsonResponse(OpCode::NOOP, "{}");
+}
+
+void CalibreWirelessActivity::receiveBinaryData() {
+  const int available = tcpClient.available();
+  if (available == 0) {
+    // Check if connection is still alive
+    if (!tcpClient.connected()) {
+      currentFile.close();
+      inBinaryMode = false;
+      setError("Transfer interrupted");
+    }
+    return;
+  }
+
+  uint8_t buffer[1024];
+  const size_t toRead = std::min(sizeof(buffer), binaryBytesRemaining);
+  const size_t bytesRead = tcpClient.read(buffer, toRead);
+
+  if (bytesRead > 0) {
+    currentFile.write(buffer, bytesRead);
+    bytesReceived += bytesRead;
+    binaryBytesRemaining -= bytesRead;
+    updateRequired = true;
+
+    if (binaryBytesRemaining == 0) {
+      // Transfer complete
+      currentFile.flush();
+      currentFile.close();
+      inBinaryMode = false;
+
+      setState(WirelessState::WAITING);
+      setStatus("Received: " + currentFilename + "\nWaiting for more...");
+
+      // Send OK to acknowledge completion
+      sendJsonResponse(OpCode::OK, "{}");
+    }
+  }
+}
+
+void CalibreWirelessActivity::render() const {
+  renderer.clearScreen();
+
+  const auto pageWidth = renderer.getScreenWidth();
+  const auto pageHeight = renderer.getScreenHeight();
+
+  // Draw header
+  renderer.drawCenteredText(UI_12_FONT_ID, 30, "Calibre Wireless", true, EpdFontFamily::BOLD);
+
+  // Draw IP address
+  const std::string ipAddr = WiFi.localIP().toString().c_str();
+  renderer.drawCenteredText(UI_10_FONT_ID, 60, ("IP: " + ipAddr).c_str());
+
+  // Draw status message
+  int statusY = pageHeight / 2 - 40;
+
+  // Split status message by newlines and draw each line
+  std::string status = statusMessage;
+  size_t pos = 0;
+  while ((pos = status.find('\n')) != std::string::npos) {
+    renderer.drawCenteredText(UI_10_FONT_ID, statusY, status.substr(0, pos).c_str());
+    statusY += 25;
+    status = status.substr(pos + 1);
+  }
+  if (!status.empty()) {
+    renderer.drawCenteredText(UI_10_FONT_ID, statusY, status.c_str());
+    statusY += 25;
+  }
+
+  // Draw progress if receiving
+  if (state == WirelessState::RECEIVING && currentFileSize > 0) {
+    const int barWidth = pageWidth - 100;
+    constexpr int barHeight = 20;
+    constexpr int barX = 50;
+    const int barY = statusY + 20;
+    ScreenComponents::drawProgressBar(renderer, barX, barY, barWidth, barHeight, bytesReceived, currentFileSize);
+  }
+
+  // Draw error if present
+  if (!errorMessage.empty()) {
+    renderer.drawCenteredText(UI_10_FONT_ID, pageHeight - 120, errorMessage.c_str());
+  }
+
+  // Draw button hints
+  const auto labels = mappedInput.mapLabels("Back", "", "", "");
+  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+
+  renderer.displayBuffer();
+}
+
+std::string CalibreWirelessActivity::getDeviceUuid() const {
+  // Generate a consistent UUID based on MAC address
+  uint8_t mac[6];
+  WiFi.macAddress(mac);
+
+  char uuid[37];
+  snprintf(uuid, sizeof(uuid), "%02x%02x%02x%02x-%02x%02x-4000-8000-%02x%02x%02x%02x%02x%02x", mac[0], mac[1], mac[2],
+           mac[3], mac[4], mac[5], mac[0], mac[1], mac[2], mac[3], mac[4], mac[5]);
+
+  return std::string(uuid);
+}
+
+void CalibreWirelessActivity::setState(WirelessState newState) {
+  xSemaphoreTake(stateMutex, portMAX_DELAY);
+  state = newState;
+  xSemaphoreGive(stateMutex);
+  updateRequired = true;
+}
+
+void CalibreWirelessActivity::setStatus(const std::string& message) {
+  statusMessage = message;
+  updateRequired = true;
+}
+
+void CalibreWirelessActivity::setError(const std::string& message) {
+  errorMessage = message;
+  setState(WirelessState::ERROR);
+}

src/activities/network/CalibreWirelessActivity.h

@@ -0,0 +1,135 @@
+#pragma once
+#include <SDCardManager.h>
+#include <WiFiClient.h>
+#include <WiFiUdp.h>
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <functional>
+#include <string>
+
+#include "activities/Activity.h"
+
+/**
+ * CalibreWirelessActivity implements Calibre's "wireless device" protocol.
+ * This allows Calibre desktop to send books directly to the device over WiFi.
+ *
+ * Protocol specification sourced from Calibre's smart device driver:
+ * https://github.com/kovidgoyal/calibre/blob/master/src/calibre/devices/smart_device_app/driver.py
+ *
+ * Protocol overview:
+ * 1. Device broadcasts "hello" on UDP ports 54982, 48123, 39001, 44044, 59678
+ * 2. Calibre responds with its TCP server address
+ * 3. Device connects to Calibre's TCP server
+ * 4. Calibre sends JSON commands with length-prefixed messages
+ * 5. Books are transferred as binary data after SEND_BOOK command
+ */
+class CalibreWirelessActivity final : public Activity {
+  // Calibre wireless device states
+  enum class WirelessState {
+    DISCOVERING,   // Listening for Calibre server broadcasts
+    CONNECTING,    // Establishing TCP connection
+    WAITING,       // Connected, waiting for commands
+    RECEIVING,     // Receiving a book file
+    COMPLETE,      // Transfer complete
+    DISCONNECTED,  // Calibre disconnected
+    ERROR          // Connection/transfer error
+  };
+
+  // Calibre protocol opcodes (from calibre/devices/smart_device_app/driver.py)
+  enum OpCode : uint8_t {
+    OK = 0,
+    SET_CALIBRE_DEVICE_INFO = 1,
+    SET_CALIBRE_DEVICE_NAME = 2,
+    GET_DEVICE_INFORMATION = 3,
+    TOTAL_SPACE = 4,
+    FREE_SPACE = 5,
+    GET_BOOK_COUNT = 6,
+    SEND_BOOKLISTS = 7,
+    SEND_BOOK = 8,
+    GET_INITIALIZATION_INFO = 9,
+    BOOK_DONE = 11,
+    NOOP = 12,  // Was incorrectly 18
+    DELETE_BOOK = 13,
+    GET_BOOK_FILE_SEGMENT = 14,
+    GET_BOOK_METADATA = 15,
+    SEND_BOOK_METADATA = 16,
+    DISPLAY_MESSAGE = 17,
+    CALIBRE_BUSY = 18,
+    SET_LIBRARY_INFO = 19,
+    ERROR = 20,
+  };
+
+  TaskHandle_t displayTaskHandle = nullptr;
+  TaskHandle_t networkTaskHandle = nullptr;
+  SemaphoreHandle_t renderingMutex = nullptr;
+  SemaphoreHandle_t stateMutex = nullptr;
+  bool updateRequired = false;
+
+  WirelessState state = WirelessState::DISCOVERING;
+  const std::function<void()> onComplete;
+
+  // UDP discovery
+  WiFiUDP udp;
+
+  // TCP connection (we connect to Calibre)
+  WiFiClient tcpClient;
+  std::string calibreHost;
+  uint16_t calibrePort = 0;
+  uint16_t calibreAltPort = 0;  // Alternative port (content server)
+  std::string calibreHostname;
+
+  // Transfer state
+  std::string currentFilename;
+  size_t currentFileSize = 0;
+  size_t bytesReceived = 0;
+  std::string statusMessage;
+  std::string errorMessage;
+
+  // Protocol state
+  bool inBinaryMode = false;
+  size_t binaryBytesRemaining = 0;
+  FsFile currentFile;
+  std::string recvBuffer;  // Buffer for incoming data (like KOReader)
+
+  static void displayTaskTrampoline(void* param);
+  static void networkTaskTrampoline(void* param);
+  [[noreturn]] void displayTaskLoop();
+  [[noreturn]] void networkTaskLoop();
+  void render() const;
+
+  // Network operations
+  void listenForDiscovery();
+  void handleTcpClient();
+  bool readJsonMessage(std::string& message);
+  void sendJsonResponse(OpCode opcode, const std::string& data);
+  void handleCommand(OpCode opcode, const std::string& data);
+  void receiveBinaryData();
+
+  // Protocol handlers
+  void handleGetInitializationInfo(const std::string& data);
+  void handleGetDeviceInformation();
+  void handleFreeSpace();
+  void handleGetBookCount();
+  void handleSendBook(const std::string& data);
+  void handleSendBookMetadata(const std::string& data);
+  void handleDisplayMessage(const std::string& data);
+  void handleNoop(const std::string& data);
+
+  // Utility
+  std::string getDeviceUuid() const;
+  void setState(WirelessState newState);
+  void setStatus(const std::string& message);
+  void setError(const std::string& message);
+
+ public:
+  explicit CalibreWirelessActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
+                                   const std::function<void()>& onComplete)
+      : Activity("CalibreWireless", renderer, mappedInput), onComplete(onComplete) {}
+  void onEnter() override;
+  void onExit() override;
+  void loop() override;
+  bool preventAutoSleep() override { return true; }
+  bool skipLoopDelay() override { return true; }
+};

src/activities/network/CrossPointWebServerActivity.cpp

@@ -334,7 +334,7 @@ void CrossPointWebServerActivity::render() const {
   } else if (state == WebServerActivityState::AP_STARTING) {
     renderer.clearScreen();
     const auto pageHeight = renderer.getScreenHeight();
-    renderer.drawCenteredText(UI_12_FONT_ID, pageHeight / 2 - 20, "Starting Hotspot...", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, pageHeight / 2 - 20, "Starting Hotspot...", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
   }
 }
@@ -365,13 +365,13 @@ void CrossPointWebServerActivity::renderServerRunning() const {
   // Use consistent line spacing
   constexpr int LINE_SPACING = 28;  // Space between lines
 
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "File Transfer", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "File Transfer", true, EpdFontFamily::BOLD);
 
   if (isApMode) {
     // AP mode display - center the content block
     int startY = 55;
 
-    renderer.drawCenteredText(UI_10_FONT_ID, startY, "Hotspot Mode", true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, startY, "Hotspot Mode", true, EpdFontFamily::BOLD);
 
     std::string ssidInfo = "Network: " + connectedSSID;
     renderer.drawCenteredText(UI_10_FONT_ID, startY + LINE_SPACING, ssidInfo.c_str());
@@ -381,13 +381,13 @@ void CrossPointWebServerActivity::renderServerRunning() const {
     renderer.drawCenteredText(SMALL_FONT_ID, startY + LINE_SPACING * 3,
                               "or scan QR code with your phone to connect to Wifi.");
     // Show QR code for URL
-    std::string wifiConfig = std::string("WIFI:T:WPA;S:") + connectedSSID + ";P:" + "" + ";;";
+    const std::string wifiConfig = std::string("WIFI:S:") + connectedSSID + ";;";
     drawQRCode(renderer, (480 - 6 * 33) / 2, startY + LINE_SPACING * 4, wifiConfig);
 
     startY += 6 * 29 + 3 * LINE_SPACING;
     // Show primary URL (hostname)
     std::string hostnameUrl = std::string("http://") + AP_HOSTNAME + ".local/";
-    renderer.drawCenteredText(UI_10_FONT_ID, startY + LINE_SPACING * 3, hostnameUrl.c_str(), true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, startY + LINE_SPACING * 3, hostnameUrl.c_str(), true, EpdFontFamily::BOLD);
 
     // Show IP address as fallback
     std::string ipUrl = "or http://" + connectedIP + "/";
@@ -412,7 +412,7 @@ void CrossPointWebServerActivity::renderServerRunning() const {
 
     // Show web server URL prominently
     std::string webInfo = "http://" + connectedIP + "/";
-    renderer.drawCenteredText(UI_10_FONT_ID, startY + LINE_SPACING * 2, webInfo.c_str(), true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, startY + LINE_SPACING * 2, webInfo.c_str(), true, EpdFontFamily::BOLD);
 
     // Also show hostname URL
     std::string hostnameUrl = std::string("or http://") + AP_HOSTNAME + ".local/";

src/activities/network/CrossPointWebServerActivity.h

@@ -70,4 +70,5 @@ class CrossPointWebServerActivity final : public ActivityWithSubactivity {
   void onExit() override;
   void loop() override;
   bool skipLoopDelay() override { return webServer && webServer->isRunning(); }
+  bool preventAutoSleep() override { return webServer && webServer->isRunning(); }
 };

src/activities/network/NetworkModeSelectionActivity.cpp

@@ -97,7 +97,7 @@ void NetworkModeSelectionActivity::render() const {
   const auto pageHeight = renderer.getScreenHeight();
 
   // Draw header
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "File Transfer", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "File Transfer", true, EpdFontFamily::BOLD);
 
   // Draw subtitle
   renderer.drawCenteredText(UI_10_FONT_ID, 50, "How would you like to connect?");

src/activities/network/WifiSelectionActivity.cpp

@@ -447,7 +447,16 @@ std::string WifiSelectionActivity::getSignalStrengthIndicator(const int32_t rssi
 
 void WifiSelectionActivity::displayTaskLoop() {
   while (true) {
+    // If a subactivity is active, yield CPU time but don't render
     if (subActivity) {
+      vTaskDelay(10 / portTICK_PERIOD_MS);
+      continue;
+    }
+
+    // Don't render if we're in PASSWORD_ENTRY state - we're just transitioning
+    // from the keyboard subactivity back to the main activity
+    if (state == WifiSelectionState::PASSWORD_ENTRY) {
+      vTaskDelay(10 / portTICK_PERIOD_MS);
       continue;
     }
 
@@ -496,7 +505,7 @@ void WifiSelectionActivity::renderNetworkList() const {
   const auto pageHeight = renderer.getScreenHeight();
 
   // Draw header
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "WiFi Networks", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "WiFi Networks", true, EpdFontFamily::BOLD);
 
   if (networks.empty()) {
     // No networks found or scan failed
@@ -577,7 +586,7 @@ void WifiSelectionActivity::renderConnecting() const {
   if (state == WifiSelectionState::SCANNING) {
     renderer.drawCenteredText(UI_10_FONT_ID, top, "Scanning...");
   } else {
-    renderer.drawCenteredText(UI_12_FONT_ID, top - 40, "Connecting...", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, top - 40, "Connecting...", true, EpdFontFamily::BOLD);
 
     std::string ssidInfo = "to " + selectedSSID;
     if (ssidInfo.length() > 25) {
@@ -592,7 +601,7 @@ void WifiSelectionActivity::renderConnected() const {
   const auto height = renderer.getLineHeight(UI_10_FONT_ID);
   const auto top = (pageHeight - height * 4) / 2;
 
-  renderer.drawCenteredText(UI_12_FONT_ID, top - 30, "Connected!", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, top - 30, "Connected!", true, EpdFontFamily::BOLD);
 
   std::string ssidInfo = "Network: " + selectedSSID;
   if (ssidInfo.length() > 28) {
@@ -612,7 +621,7 @@ void WifiSelectionActivity::renderSavePrompt() const {
   const auto height = renderer.getLineHeight(UI_10_FONT_ID);
   const auto top = (pageHeight - height * 3) / 2;
 
-  renderer.drawCenteredText(UI_12_FONT_ID, top - 40, "Connected!", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, top - 40, "Connected!", true, EpdFontFamily::BOLD);
 
   std::string ssidInfo = "Network: " + selectedSSID;
   if (ssidInfo.length() > 28) {
@@ -651,7 +660,7 @@ void WifiSelectionActivity::renderConnectionFailed() const {
   const auto height = renderer.getLineHeight(UI_10_FONT_ID);
   const auto top = (pageHeight - height * 2) / 2;
 
-  renderer.drawCenteredText(UI_12_FONT_ID, top - 20, "Connection Failed", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, top - 20, "Connection Failed", true, EpdFontFamily::BOLD);
   renderer.drawCenteredText(UI_10_FONT_ID, top + 20, connectionError.c_str());
   renderer.drawCenteredText(SMALL_FONT_ID, pageHeight - 30, "Press any button to continue");
 }
@@ -662,7 +671,7 @@ void WifiSelectionActivity::renderForgetPrompt() const {
   const auto height = renderer.getLineHeight(UI_10_FONT_ID);
   const auto top = (pageHeight - height * 3) / 2;
 
-  renderer.drawCenteredText(UI_12_FONT_ID, top - 40, "Forget Network?", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, top - 40, "Forget Network?", true, EpdFontFamily::BOLD);
 
   std::string ssidInfo = "Network: " + selectedSSID;
   if (ssidInfo.length() > 28) {

src/activities/reader/EpubReaderActivity.cpp

@@ -13,11 +13,9 @@
 #include "fontIds.h"
 
 namespace {
-constexpr int pagesPerRefresh = 15;
+// pagesPerRefresh now comes from SETTINGS.getRefreshFrequency()
 constexpr unsigned long skipChapterMs = 700;
 constexpr unsigned long goHomeMs = 1000;
-constexpr int topPadding = 5;
-constexpr int horizontalPadding = 5;
 constexpr int statusBarMargin = 19;
 }  // namespace
 
@@ -154,6 +152,8 @@ void EpubReaderActivity::loop() {
   const bool prevReleased = mappedInput.wasReleased(MappedInputManager::Button::PageBack) ||
                             mappedInput.wasReleased(MappedInputManager::Button::Left);
   const bool nextReleased = mappedInput.wasReleased(MappedInputManager::Button::PageForward) ||
+                            (SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::PAGE_TURN &&
+                             mappedInput.wasReleased(MappedInputManager::Button::Power)) ||
                             mappedInput.wasReleased(MappedInputManager::Button::Right);
 
   if (!prevReleased && !nextReleased) {
@@ -244,7 +244,7 @@ void EpubReaderActivity::renderScreen() {
   // Show end of book screen
   if (currentSpineIndex == epub->getSpineItemsCount()) {
     renderer.clearScreen();
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "End of book", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "End of book", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
     return;
   }
@@ -253,9 +253,9 @@ void EpubReaderActivity::renderScreen() {
   int orientedMarginTop, orientedMarginRight, orientedMarginBottom, orientedMarginLeft;
   renderer.getOrientedViewableTRBL(&orientedMarginTop, &orientedMarginRight, &orientedMarginBottom,
                                    &orientedMarginLeft);
-  orientedMarginTop += topPadding;
+  orientedMarginTop += SETTINGS.screenMargin;
-  orientedMarginLeft += horizontalPadding;
+  orientedMarginLeft += SETTINGS.screenMargin;
-  orientedMarginRight += horizontalPadding;
+  orientedMarginRight += SETTINGS.screenMargin;
   orientedMarginBottom += statusBarMargin;
 
   if (!section) {
@@ -263,11 +263,12 @@ void EpubReaderActivity::renderScreen() {
     Serial.printf("[%lu] [ERS] Loading file: %s, index: %d\n", millis(), filepath.c_str(), currentSpineIndex);
     section = std::unique_ptr<Section>(new Section(epub, currentSpineIndex, renderer));
 
-    const auto viewportWidth = renderer.getScreenWidth() - orientedMarginLeft - orientedMarginRight;
+    const uint16_t viewportWidth = renderer.getScreenWidth() - orientedMarginLeft - orientedMarginRight;
-    const auto viewportHeight = renderer.getScreenHeight() - orientedMarginTop - orientedMarginBottom;
+    const uint16_t viewportHeight = renderer.getScreenHeight() - orientedMarginTop - orientedMarginBottom;
 
     if (!section->loadSectionFile(SETTINGS.getReaderFontId(), SETTINGS.getReaderLineCompression(),
-                                  SETTINGS.extraParagraphSpacing, viewportWidth, viewportHeight)) {
+                                  SETTINGS.extraParagraphSpacing, SETTINGS.paragraphAlignment, viewportWidth,
+                                  viewportHeight)) {
       Serial.printf("[%lu] [ERS] Cache not found, building...\n", millis());
 
       // Progress bar dimensions
@@ -311,8 +312,8 @@ void EpubReaderActivity::renderScreen() {
       };
 
       if (!section->createSectionFile(SETTINGS.getReaderFontId(), SETTINGS.getReaderLineCompression(),
-                                      SETTINGS.extraParagraphSpacing, viewportWidth, viewportHeight, progressSetup,
+                                      SETTINGS.extraParagraphSpacing, SETTINGS.paragraphAlignment, viewportWidth,
-                                      progressCallback)) {
+                                      viewportHeight, progressSetup, progressCallback)) {
         Serial.printf("[%lu] [ERS] Failed to persist page data to SD\n", millis());
         section.reset();
         return;
@@ -332,7 +333,7 @@ void EpubReaderActivity::renderScreen() {
 
   if (section->pageCount == 0) {
     Serial.printf("[%lu] [ERS] No pages to render\n", millis());
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Empty chapter", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Empty chapter", true, EpdFontFamily::BOLD);
     renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
     renderer.displayBuffer();
     return;
@@ -340,7 +341,7 @@ void EpubReaderActivity::renderScreen() {
 
   if (section->currentPage < 0 || section->currentPage >= section->pageCount) {
     Serial.printf("[%lu] [ERS] Page out of bounds: %d (max %d)\n", millis(), section->currentPage, section->pageCount);
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Out of bounds", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Out of bounds", true, EpdFontFamily::BOLD);
     renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
     renderer.displayBuffer();
     return;
@@ -378,7 +379,7 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
   renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
   if (pagesUntilFullRefresh <= 1) {
     renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
-    pagesUntilFullRefresh = pagesPerRefresh;
+    pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();
     pagesUntilFullRefresh--;
@@ -389,7 +390,7 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
 
   // grayscale rendering
   // TODO: Only do this if font supports it
-  {
+  if (SETTINGS.textAntiAliasing) {
     renderer.clearScreen(0x00);
     renderer.setRenderMode(GfxRenderer::GRAYSCALE_LSB);
     page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
@@ -418,6 +419,8 @@ void EpubReaderActivity::renderStatusBar(const int orientedMarginRight, const in
                            SETTINGS.statusBar == CrossPointSettings::STATUS_BAR_MODE::FULL;
   const bool showChapterTitle = SETTINGS.statusBar == CrossPointSettings::STATUS_BAR_MODE::NO_PROGRESS ||
                                 SETTINGS.statusBar == CrossPointSettings::STATUS_BAR_MODE::FULL;
+  const bool showBatteryPercentage =
+      SETTINGS.hideBatteryPercentage == CrossPointSettings::HIDE_BATTERY_PERCENTAGE::HIDE_NEVER;
 
   // Position status bar near the bottom of the logical screen, regardless of orientation
   const auto screenHeight = renderer.getScreenHeight();
@@ -438,7 +441,7 @@ void EpubReaderActivity::renderStatusBar(const int orientedMarginRight, const in
   }
 
   if (showBattery) {
-    ScreenComponents::drawBattery(renderer, orientedMarginLeft, textY);
+    ScreenComponents::drawBattery(renderer, orientedMarginLeft + 1, textY, showBatteryPercentage);
   }
 
   if (showChapterTitle) {

src/activities/reader/EpubReaderChapterSelectionActivity.cpp

@@ -16,7 +16,9 @@ int EpubReaderChapterSelectionActivity::getPageItems() const {
   constexpr int lineHeight = 30;
 
   const int screenHeight = renderer.getScreenHeight();
-  const int availableHeight = screenHeight - startY;
+  const int endY = screenHeight - lineHeight;
+
+  const int availableHeight = endY - startY;
   int items = availableHeight / lineHeight;
 
   // Ensure we always have at least one item per page to avoid division by zero
@@ -120,7 +122,10 @@ void EpubReaderChapterSelectionActivity::renderScreen() {
 
   const auto pageWidth = renderer.getScreenWidth();
   const int pageItems = getPageItems();
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Select Chapter", true, BOLD);
+
+  const std::string title =
+      renderer.truncatedText(UI_12_FONT_ID, epub->getTitle().c_str(), pageWidth - 40, EpdFontFamily::BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, title.c_str(), true, EpdFontFamily::BOLD);
 
   const auto pageStartIndex = selectorIndex / pageItems * pageItems;
   renderer.fillRect(0, 60 + (selectorIndex % pageItems) * 30 - 2, pageWidth - 1, 30);
@@ -131,5 +136,8 @@ void EpubReaderChapterSelectionActivity::renderScreen() {
                       tocIndex != selectorIndex);
   }
 
+  const auto labels = mappedInput.mapLabels("« Back", "Select", "Up", "Down");
+  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+
   renderer.displayBuffer();
 }

src/activities/reader/FileSelectionActivity.cpp

@@ -5,6 +5,7 @@
 
 #include "MappedInputManager.h"
 #include "fontIds.h"
+#include "util/StringUtils.h"
 
 namespace {
 constexpr int PAGE_ITEMS = 23;
@@ -29,12 +30,19 @@ void FileSelectionActivity::taskTrampoline(void* param) {
 
 void FileSelectionActivity::loadFiles() {
   files.clear();
-  selectorIndex = 0;
+
   auto root = SdMan.open(basepath.c_str());
-  char name[128];
+  if (!root || !root.isDirectory()) {
+    if (root) root.close();
+    return;
+  }
+
+  root.rewindDirectory();
+
+  char name[500];
   for (auto file = root.openNextFile(); file; file = root.openNextFile()) {
     file.getName(name, sizeof(name));
-    if (name[0] == '.') {
+    if (name[0] == '.' || strcmp(name, "System Volume Information") == 0) {
       file.close();
       continue;
     }
@@ -43,9 +51,8 @@ void FileSelectionActivity::loadFiles() {
       files.emplace_back(std::string(name) + "/");
     } else {
       auto filename = std::string(name);
-      std::string ext4 = filename.length() >= 4 ? filename.substr(filename.length() - 4) : "";
+      if (StringUtils::checkFileExtension(filename, ".epub") || StringUtils::checkFileExtension(filename, ".xtch") ||
-      std::string ext5 = filename.length() >= 5 ? filename.substr(filename.length() - 5) : "";
+          StringUtils::checkFileExtension(filename, ".xtc")) {
-      if (ext5 == ".epub" || ext5 == ".xtch" || ext4 == ".xtc") {
         files.emplace_back(filename);
       }
     }
@@ -116,6 +123,7 @@ void FileSelectionActivity::loop() {
     if (files[selectorIndex].back() == '/') {
       basepath += files[selectorIndex].substr(0, files[selectorIndex].length() - 1);
       loadFiles();
+      selectorIndex = 0;
       updateRequired = true;
     } else {
       onSelect(basepath + files[selectorIndex]);
@@ -124,9 +132,16 @@ void FileSelectionActivity::loop() {
     // Short press: go up one directory, or go home if at root
     if (mappedInput.getHeldTime() < GO_HOME_MS) {
       if (basepath != "/") {
+        const std::string oldPath = basepath;
+
         basepath.replace(basepath.find_last_of('/'), std::string::npos, "");
         if (basepath.empty()) basepath = "/";
         loadFiles();
+
+        const auto pos = oldPath.find_last_of('/');
+        const std::string dirName = oldPath.substr(pos + 1) + "/";
+        selectorIndex = findEntry(dirName);
+
         updateRequired = true;
       } else {
         onGoHome();
@@ -165,7 +180,7 @@ void FileSelectionActivity::render() const {
   renderer.clearScreen();
 
   const auto pageWidth = renderer.getScreenWidth();
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Books", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Books", true, EpdFontFamily::BOLD);
 
   // Help text
   const auto labels = mappedInput.mapLabels("« Home", "Open", "", "");
@@ -179,15 +194,16 @@ void FileSelectionActivity::render() const {
 
   const auto pageStartIndex = selectorIndex / PAGE_ITEMS * PAGE_ITEMS;
   renderer.fillRect(0, 60 + (selectorIndex % PAGE_ITEMS) * 30 - 2, pageWidth - 1, 30);
-  for (int i = pageStartIndex; i < files.size() && i < pageStartIndex + PAGE_ITEMS; i++) {
+  for (size_t i = pageStartIndex; i < files.size() && i < pageStartIndex + PAGE_ITEMS; i++) {
-    auto item = files[i];
+    auto item = renderer.truncatedText(UI_10_FONT_ID, files[i].c_str(), renderer.getScreenWidth() - 40);
-    int itemWidth = renderer.getTextWidth(UI_10_FONT_ID, item.c_str());
-    while (itemWidth > renderer.getScreenWidth() - 40 && item.length() > 8) {
-      item.replace(item.length() - 5, 5, "...");
-      itemWidth = renderer.getTextWidth(UI_10_FONT_ID, item.c_str());
-    }
     renderer.drawText(UI_10_FONT_ID, 20, 60 + (i % PAGE_ITEMS) * 30, item.c_str(), i != selectorIndex);
   }
 
   renderer.displayBuffer();
 }
+
+size_t FileSelectionActivity::findEntry(const std::string& name) const {
+  for (size_t i = 0; i < files.size(); i++)
+    if (files[i] == name) return i;
+  return 0;
+}

src/activities/reader/FileSelectionActivity.h

@@ -14,7 +14,7 @@ class FileSelectionActivity final : public Activity {
   SemaphoreHandle_t renderingMutex = nullptr;
   std::string basepath = "/";
   std::vector<std::string> files;
-  int selectorIndex = 0;
+  size_t selectorIndex = 0;
   bool updateRequired = false;
   const std::function<void(const std::string&)> onSelect;
   const std::function<void()> onGoHome;
@@ -24,6 +24,8 @@ class FileSelectionActivity final : public Activity {
   void render() const;
   void loadFiles();
 
+  size_t findEntry(const std::string& name) const;
+
  public:
   explicit FileSelectionActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
                                  const std::function<void(const std::string&)>& onSelect,

src/activities/reader/ReaderActivity.cpp

@@ -6,6 +6,7 @@
 #include "Xtc.h"
 #include "XtcReaderActivity.h"
 #include "activities/util/FullScreenMessageActivity.h"
+#include "util/StringUtils.h"
 
 std::string ReaderActivity::extractFolderPath(const std::string& filePath) {
   const auto lastSlash = filePath.find_last_of('/');
@@ -16,14 +17,7 @@ std::string ReaderActivity::extractFolderPath(const std::string& filePath) {
 }
 
 bool ReaderActivity::isXtcFile(const std::string& path) {
-  if (path.length() < 4) return false;
+  return StringUtils::checkFileExtension(path, ".xtc") || StringUtils::checkFileExtension(path, ".xtch");
-  std::string ext4 = path.substr(path.length() - 4);
-  if (ext4 == ".xtc") return true;
-  if (path.length() >= 5) {
-    std::string ext5 = path.substr(path.length() - 5);
-    if (ext5 == ".xtch") return true;
-  }
-  return false;
 }
 
 std::unique_ptr<Epub> ReaderActivity::loadEpub(const std::string& path) {
@@ -68,8 +62,8 @@ void ReaderActivity::onSelectBookFile(const std::string& path) {
       onGoToXtcReader(std::move(xtc));
     } else {
       exitActivity();
-      enterNewActivity(new FullScreenMessageActivity(renderer, mappedInput, "Failed to load XTC", REGULAR,
+      enterNewActivity(new FullScreenMessageActivity(renderer, mappedInput, "Failed to load XTC",
-                                                     EInkDisplay::HALF_REFRESH));
+                                                     EpdFontFamily::REGULAR, EInkDisplay::HALF_REFRESH));
       delay(2000);
       onGoToFileSelection();
     }
@@ -80,8 +74,8 @@ void ReaderActivity::onSelectBookFile(const std::string& path) {
       onGoToEpubReader(std::move(epub));
     } else {
       exitActivity();
-      enterNewActivity(new FullScreenMessageActivity(renderer, mappedInput, "Failed to load epub", REGULAR,
+      enterNewActivity(new FullScreenMessageActivity(renderer, mappedInput, "Failed to load epub",
-                                                     EInkDisplay::HALF_REFRESH));
+                                                     EpdFontFamily::REGULAR, EInkDisplay::HALF_REFRESH));
       delay(2000);
       onGoToFileSelection();
     }

src/activities/reader/XtcReaderActivity.cpp

@@ -11,13 +11,13 @@
 #include <GfxRenderer.h>
 #include <SDCardManager.h>
 
+#include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "MappedInputManager.h"
 #include "XtcReaderChapterSelectionActivity.h"
 #include "fontIds.h"
 
 namespace {
-constexpr int pagesPerRefresh = 15;
 constexpr unsigned long skipPageMs = 700;
 constexpr unsigned long goHomeMs = 1000;
 }  // namespace
@@ -112,6 +112,8 @@ void XtcReaderActivity::loop() {
   const bool prevReleased = mappedInput.wasReleased(MappedInputManager::Button::PageBack) ||
                             mappedInput.wasReleased(MappedInputManager::Button::Left);
   const bool nextReleased = mappedInput.wasReleased(MappedInputManager::Button::PageForward) ||
+                            (SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::PAGE_TURN &&
+                             mappedInput.wasReleased(MappedInputManager::Button::Power)) ||
                             mappedInput.wasReleased(MappedInputManager::Button::Right);
 
   if (!prevReleased && !nextReleased) {
@@ -165,7 +167,7 @@ void XtcReaderActivity::renderScreen() {
   if (currentPage >= xtc->getPageCount()) {
     // Show end of book screen
     renderer.clearScreen();
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "End of book", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "End of book", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
     return;
   }
@@ -194,7 +196,7 @@ void XtcReaderActivity::renderPage() {
   if (!pageBuffer) {
     Serial.printf("[%lu] [XTR] Failed to allocate page buffer (%lu bytes)\n", millis(), pageBufferSize);
     renderer.clearScreen();
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Memory error", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Memory error", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
     return;
   }
@@ -205,7 +207,7 @@ void XtcReaderActivity::renderPage() {
     Serial.printf("[%lu] [XTR] Failed to load page %lu\n", millis(), currentPage);
     free(pageBuffer);
     renderer.clearScreen();
-    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Page load error", true, BOLD);
+    renderer.drawCenteredText(UI_12_FONT_ID, 300, "Page load error", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
     return;
   }
@@ -266,7 +268,7 @@ void XtcReaderActivity::renderPage() {
     // Display BW with conditional refresh based on pagesUntilFullRefresh
     if (pagesUntilFullRefresh <= 1) {
       renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
-      pagesUntilFullRefresh = pagesPerRefresh;
+      pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
     } else {
       renderer.displayBuffer();
       pagesUntilFullRefresh--;
@@ -346,7 +348,7 @@ void XtcReaderActivity::renderPage() {
   // Display with appropriate refresh
   if (pagesUntilFullRefresh <= 1) {
     renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
-    pagesUntilFullRefresh = pagesPerRefresh;
+    pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();
     pagesUntilFullRefresh--;

src/activities/reader/XtcReaderChapterSelectionActivity.cpp

@@ -14,7 +14,9 @@ int XtcReaderChapterSelectionActivity::getPageItems() const {
   constexpr int lineHeight = 30;
 
   const int screenHeight = renderer.getScreenHeight();
-  const int availableHeight = screenHeight - startY;
+  const int endY = screenHeight - lineHeight;
+
+  const int availableHeight = endY - startY;
   int items = availableHeight / lineHeight;
   if (items < 1) {
     items = 1;
@@ -130,7 +132,7 @@ void XtcReaderChapterSelectionActivity::renderScreen() {
 
   const auto pageWidth = renderer.getScreenWidth();
   const int pageItems = getPageItems();
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Select Chapter", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Select Chapter", true, EpdFontFamily::BOLD);
 
   const auto& chapters = xtc->getChapters();
   if (chapters.empty()) {
@@ -147,5 +149,8 @@ void XtcReaderChapterSelectionActivity::renderScreen() {
     renderer.drawText(UI_10_FONT_ID, 20, 60 + (i % pageItems) * 30, title, i != selectorIndex);
   }
 
+  const auto labels = mappedInput.mapLabels("« Back", "Select", "Up", "Down");
+  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+
   renderer.displayBuffer();
 }

src/activities/settings/CalibreSettingsActivity.cpp

@@ -0,0 +1,169 @@
+#include "CalibreSettingsActivity.h"
+
+#include <GfxRenderer.h>
+#include <WiFi.h>
+
+#include <cstring>
+
+#include "CrossPointSettings.h"
+#include "MappedInputManager.h"
+#include "activities/network/CalibreWirelessActivity.h"
+#include "activities/network/WifiSelectionActivity.h"
+#include "activities/util/KeyboardEntryActivity.h"
+#include "fontIds.h"
+
+namespace {
+constexpr int MENU_ITEMS = 2;
+const char* menuNames[MENU_ITEMS] = {"Calibre Web URL", "Connect as Wireless Device"};
+}  // namespace
+
+void CalibreSettingsActivity::taskTrampoline(void* param) {
+  auto* self = static_cast<CalibreSettingsActivity*>(param);
+  self->displayTaskLoop();
+}
+
+void CalibreSettingsActivity::onEnter() {
+  ActivityWithSubactivity::onEnter();
+
+  renderingMutex = xSemaphoreCreateMutex();
+  selectedIndex = 0;
+  updateRequired = true;
+
+  xTaskCreate(&CalibreSettingsActivity::taskTrampoline, "CalibreSettingsTask",
+              4096,               // Stack size
+              this,               // Parameters
+              1,                  // Priority
+              &displayTaskHandle  // Task handle
+  );
+}
+
+void CalibreSettingsActivity::onExit() {
+  ActivityWithSubactivity::onExit();
+
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+  if (displayTaskHandle) {
+    vTaskDelete(displayTaskHandle);
+    displayTaskHandle = nullptr;
+  }
+  vSemaphoreDelete(renderingMutex);
+  renderingMutex = nullptr;
+}
+
+void CalibreSettingsActivity::loop() {
+  if (subActivity) {
+    subActivity->loop();
+    return;
+  }
+
+  if (mappedInput.wasPressed(MappedInputManager::Button::Back)) {
+    onBack();
+    return;
+  }
+
+  if (mappedInput.wasPressed(MappedInputManager::Button::Confirm)) {
+    handleSelection();
+    return;
+  }
+
+  if (mappedInput.wasPressed(MappedInputManager::Button::Up) ||
+      mappedInput.wasPressed(MappedInputManager::Button::Left)) {
+    selectedIndex = (selectedIndex + MENU_ITEMS - 1) % MENU_ITEMS;
+    updateRequired = true;
+  } else if (mappedInput.wasPressed(MappedInputManager::Button::Down) ||
+             mappedInput.wasPressed(MappedInputManager::Button::Right)) {
+    selectedIndex = (selectedIndex + 1) % MENU_ITEMS;
+    updateRequired = true;
+  }
+}
+
+void CalibreSettingsActivity::handleSelection() {
+  xSemaphoreTake(renderingMutex, portMAX_DELAY);
+
+  if (selectedIndex == 0) {
+    // Calibre Web URL
+    exitActivity();
+    enterNewActivity(new KeyboardEntryActivity(
+        renderer, mappedInput, "Calibre Web URL", SETTINGS.opdsServerUrl, 10,
+        127,    // maxLength
+        false,  // not password
+        [this](const std::string& url) {
+          strncpy(SETTINGS.opdsServerUrl, url.c_str(), sizeof(SETTINGS.opdsServerUrl) - 1);
+          SETTINGS.opdsServerUrl[sizeof(SETTINGS.opdsServerUrl) - 1] = '\0';
+          SETTINGS.saveToFile();
+          exitActivity();
+          updateRequired = true;
+        },
+        [this]() {
+          exitActivity();
+          updateRequired = true;
+        }));
+  } else if (selectedIndex == 1) {
+    // Wireless Device - launch the activity (handles WiFi connection internally)
+    exitActivity();
+    if (WiFi.status() != WL_CONNECTED) {
+      enterNewActivity(new WifiSelectionActivity(renderer, mappedInput, [this](bool connected) {
+        exitActivity();
+        if (connected) {
+          enterNewActivity(new CalibreWirelessActivity(renderer, mappedInput, [this] {
+            exitActivity();
+            updateRequired = true;
+          }));
+        } else {
+          updateRequired = true;
+        }
+      }));
+    } else {
+      enterNewActivity(new CalibreWirelessActivity(renderer, mappedInput, [this] {
+        exitActivity();
+        updateRequired = true;
+      }));
+    }
+  }
+
+  xSemaphoreGive(renderingMutex);
+}
+
+void CalibreSettingsActivity::displayTaskLoop() {
+  while (true) {
+    if (updateRequired && !subActivity) {
+      updateRequired = false;
+      xSemaphoreTake(renderingMutex, portMAX_DELAY);
+      render();
+      xSemaphoreGive(renderingMutex);
+    }
+    vTaskDelay(10 / portTICK_PERIOD_MS);
+  }
+}
+
+void CalibreSettingsActivity::render() {
+  renderer.clearScreen();
+
+  const auto pageWidth = renderer.getScreenWidth();
+
+  // Draw header
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Calibre", true, EpdFontFamily::BOLD);
+
+  // Draw selection highlight
+  renderer.fillRect(0, 60 + selectedIndex * 30 - 2, pageWidth - 1, 30);
+
+  // Draw menu items
+  for (int i = 0; i < MENU_ITEMS; i++) {
+    const int settingY = 60 + i * 30;
+    const bool isSelected = (i == selectedIndex);
+
+    renderer.drawText(UI_10_FONT_ID, 20, settingY, menuNames[i], !isSelected);
+
+    // Draw status for URL setting
+    if (i == 0) {
+      const char* status = (strlen(SETTINGS.opdsServerUrl) > 0) ? "[Set]" : "[Not Set]";
+      const auto width = renderer.getTextWidth(UI_10_FONT_ID, status);
+      renderer.drawText(UI_10_FONT_ID, pageWidth - 20 - width, settingY, status, !isSelected);
+    }
+  }
+
+  // Draw button hints
+  const auto labels = mappedInput.mapLabels("« Back", "Select", "", "");
+  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+
+  renderer.displayBuffer();
+}

src/activities/settings/CalibreSettingsActivity.h

@@ -0,0 +1,36 @@
+#pragma once
+#include <freertos/FreeRTOS.h>
+#include <freertos/semphr.h>
+#include <freertos/task.h>
+
+#include <functional>
+
+#include "activities/ActivityWithSubactivity.h"
+
+/**
+ * Submenu for Calibre settings.
+ * Shows Calibre Web URL and Calibre Wireless Device options.
+ */
+class CalibreSettingsActivity final : public ActivityWithSubactivity {
+ public:
+  explicit CalibreSettingsActivity(GfxRenderer& renderer, MappedInputManager& mappedInput,
+                                   const std::function<void()>& onBack)
+      : ActivityWithSubactivity("CalibreSettings", renderer, mappedInput), onBack(onBack) {}
+
+  void onEnter() override;
+  void onExit() override;
+  void loop() override;
+
+ private:
+  TaskHandle_t displayTaskHandle = nullptr;
+  SemaphoreHandle_t renderingMutex = nullptr;
+  bool updateRequired = false;
+
+  int selectedIndex = 0;
+  const std::function<void()> onBack;
+
+  static void taskTrampoline(void* param);
+  [[noreturn]] void displayTaskLoop();
+  void render();
+  void handleSelection();
+};

src/activities/settings/OtaUpdateActivity.cpp

@@ -124,36 +124,30 @@ void OtaUpdateActivity::render() {
     lastUpdaterPercentage = static_cast<int>(updaterProgress * 100);
   }
 
-  const auto pageHeight = renderer.getScreenHeight();
   const auto pageWidth = renderer.getScreenWidth();
 
   renderer.clearScreen();
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Update", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Update", true, EpdFontFamily::BOLD);
 
   if (state == CHECKING_FOR_UPDATE) {
-    renderer.drawCenteredText(UI_10_FONT_ID, 300, "Checking for update...", true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, 300, "Checking for update...", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
     return;
   }
 
   if (state == WAITING_CONFIRMATION) {
-    renderer.drawCenteredText(UI_10_FONT_ID, 200, "New update available!", true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, 200, "New update available!", true, EpdFontFamily::BOLD);
     renderer.drawText(UI_10_FONT_ID, 20, 250, "Current Version: " CROSSPOINT_VERSION);
     renderer.drawText(UI_10_FONT_ID, 20, 270, ("New Version: " + updater.getLatestVersion()).c_str());
 
-    renderer.drawRect(25, pageHeight - 40, 106, 40);
+    const auto labels = mappedInput.mapLabels("Cancel", "Update", "", "");
-    renderer.drawText(UI_10_FONT_ID, 25 + (105 - renderer.getTextWidth(UI_10_FONT_ID, "Cancel")) / 2, pageHeight - 35,
+    renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
-                      "Cancel");
-
-    renderer.drawRect(130, pageHeight - 40, 106, 40);
-    renderer.drawText(UI_10_FONT_ID, 130 + (105 - renderer.getTextWidth(UI_10_FONT_ID, "Update")) / 2, pageHeight - 35,
-                      "Update");
     renderer.displayBuffer();
     return;
   }
 
   if (state == UPDATE_IN_PROGRESS) {
-    renderer.drawCenteredText(UI_10_FONT_ID, 310, "Updating...", true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, 310, "Updating...", true, EpdFontFamily::BOLD);
     renderer.drawRect(20, 350, pageWidth - 40, 50);
     renderer.fillRect(24, 354, static_cast<int>(updaterProgress * static_cast<float>(pageWidth - 44)), 42);
     renderer.drawCenteredText(UI_10_FONT_ID, 420,
@@ -166,19 +160,19 @@ void OtaUpdateActivity::render() {
   }
 
   if (state == NO_UPDATE) {
-    renderer.drawCenteredText(UI_10_FONT_ID, 300, "No update available", true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, 300, "No update available", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
     return;
   }
 
   if (state == FAILED) {
-    renderer.drawCenteredText(UI_10_FONT_ID, 300, "Update failed", true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, 300, "Update failed", true, EpdFontFamily::BOLD);
     renderer.displayBuffer();
     return;
   }
 
   if (state == FINISHED) {
-    renderer.drawCenteredText(UI_10_FONT_ID, 300, "Update complete", true, BOLD);
+    renderer.drawCenteredText(UI_10_FONT_ID, 300, "Update complete", true, EpdFontFamily::BOLD);
     renderer.drawCenteredText(UI_10_FONT_ID, 350, "Press and hold power button to turn back on");
     renderer.displayBuffer();
     state = SHUTTING_DOWN;

src/activities/settings/OtaUpdateActivity.h

@@ -41,4 +41,5 @@ class OtaUpdateActivity : public ActivityWithSubactivity {
   void onEnter() override;
   void onExit() override;
   void loop() override;
+  bool preventAutoSleep() override { return state == CHECKING_FOR_UPDATE || state == UPDATE_IN_PROGRESS; }
 };

src/activities/settings/SettingsActivity.cpp

@@ -1,7 +1,11 @@
 #include "SettingsActivity.h"
 
 #include <GfxRenderer.h>
+#include <HardwareSerial.h>
 
+#include <cstring>
+
+#include "CalibreSettingsActivity.h"
 #include "CrossPointSettings.h"
 #include "MappedInputManager.h"
 #include "OtaUpdateActivity.h"
@@ -9,33 +13,35 @@
 
 // Define the static settings list
 namespace {
-constexpr int settingsCount = 11;
+constexpr int settingsCount = 19;
 const SettingInfo settingsList[settingsCount] = {
     // Should match with SLEEP_SCREEN_MODE
-    {"Sleep Screen", SettingType::ENUM, &CrossPointSettings::sleepScreen, {"Dark", "Light", "Custom", "Cover"}},
+    SettingInfo::Enum("Sleep Screen", &CrossPointSettings::sleepScreen, {"Dark", "Light", "Custom", "Cover", "None"}),
-    {"Status Bar", SettingType::ENUM, &CrossPointSettings::statusBar, {"None", "No Progress", "Full"}},
+    SettingInfo::Enum("Sleep Screen Cover Mode", &CrossPointSettings::sleepScreenCoverMode, {"Fit", "Crop"}),
-    {"Extra Paragraph Spacing", SettingType::TOGGLE, &CrossPointSettings::extraParagraphSpacing, {}},
+    SettingInfo::Enum("Status Bar", &CrossPointSettings::statusBar, {"None", "No Progress", "Full"}),
-    {"Short Power Button Click", SettingType::TOGGLE, &CrossPointSettings::shortPwrBtn, {}},
+    SettingInfo::Enum("Hide Battery %", &CrossPointSettings::hideBatteryPercentage, {"Never", "In Reader", "Always"}),
-    {"Reading Orientation",
+    SettingInfo::Toggle("Extra Paragraph Spacing", &CrossPointSettings::extraParagraphSpacing),
-     SettingType::ENUM,
+    SettingInfo::Toggle("Text Anti-Aliasing", &CrossPointSettings::textAntiAliasing),
-     &CrossPointSettings::orientation,
+    SettingInfo::Enum("Short Power Button Click", &CrossPointSettings::shortPwrBtn, {"Ignore", "Sleep", "Page Turn"}),
-     {"Portrait", "Landscape CW", "Inverted", "Landscape CCW"}},
+    SettingInfo::Enum("Reading Orientation", &CrossPointSettings::orientation,
-    {"Front Button Layout",
+                      {"Portrait", "Landscape CW", "Inverted", "Landscape CCW"}),
-     SettingType::ENUM,
+    SettingInfo::Enum("Front Button Layout", &CrossPointSettings::frontButtonLayout,
-     &CrossPointSettings::frontButtonLayout,
+                      {"Bck, Cnfrm, Lft, Rght", "Lft, Rght, Bck, Cnfrm", "Lft, Bck, Cnfrm, Rght"}),
-     {"Bck, Cnfrm, Lft, Rght", "Lft, Rght, Bck, Cnfrm", "Lft, Bck, Cnfrm, Rght"}},
+    SettingInfo::Enum("Side Button Layout (reader)", &CrossPointSettings::sideButtonLayout,
-    {"Side Button Layout (reader)",
+                      {"Prev, Next", "Next, Prev"}),
-     SettingType::ENUM,
+    SettingInfo::Enum("Reader Font Family", &CrossPointSettings::fontFamily,
-     &CrossPointSettings::sideButtonLayout,
+                      {"Bookerly", "Noto Sans", "Open Dyslexic"}),
-     {"Prev, Next", "Next, Prev"}},
+    SettingInfo::Enum("Reader Font Size", &CrossPointSettings::fontSize, {"Small", "Medium", "Large", "X Large"}),
-    {"Reader Font Family",
+    SettingInfo::Enum("Reader Line Spacing", &CrossPointSettings::lineSpacing, {"Tight", "Normal", "Wide"}),
-     SettingType::ENUM,
+    SettingInfo::Value("Reader Screen Margin", &CrossPointSettings::screenMargin, {5, 40, 5}),
-     &CrossPointSettings::fontFamily,
+    SettingInfo::Enum("Reader Paragraph Alignment", &CrossPointSettings::paragraphAlignment,
-     {"Bookerly", "Noto Sans", "Open Dyslexic"}},
+                      {"Justify", "Left", "Center", "Right"}),
-    {"Reader Font Size", SettingType::ENUM, &CrossPointSettings::fontSize, {"Small", "Medium", "Large", "X Large"}},
+    SettingInfo::Enum("Time to Sleep", &CrossPointSettings::sleepTimeout,
-    {"Reader Line Spacing", SettingType::ENUM, &CrossPointSettings::lineSpacing, {"Tight", "Normal", "Wide"}},
+                      {"1 min", "5 min", "10 min", "15 min", "30 min"}),
-    {"Check for updates", SettingType::ACTION, nullptr, {}},
+    SettingInfo::Enum("Refresh Frequency", &CrossPointSettings::refreshFrequency,
-};
+                      {"1 page", "5 pages", "10 pages", "15 pages", "30 pages"}),
+    SettingInfo::Action("Calibre Settings"),
+    SettingInfo::Action("Check for updates")};
 }  // namespace
 
 void SettingsActivity::taskTrampoline(void* param) {
@@ -45,7 +51,6 @@ void SettingsActivity::taskTrampoline(void* param) {
 
 void SettingsActivity::onEnter() {
   Activity::onEnter();
-
   renderingMutex = xSemaphoreCreateMutex();
 
   // Reset selection to first item
@@ -55,7 +60,7 @@ void SettingsActivity::onEnter() {
   updateRequired = true;
 
   xTaskCreate(&SettingsActivity::taskTrampoline, "SettingsActivityTask",
-              2048,               // Stack size
+              4096,               // Stack size
               this,               // Parameters
               1,                  // Priority
               &displayTaskHandle  // Task handle
@@ -102,13 +107,11 @@ void SettingsActivity::loop() {
     updateRequired = true;
   } else if (mappedInput.wasPressed(MappedInputManager::Button::Down) ||
              mappedInput.wasPressed(MappedInputManager::Button::Right)) {
-    // Move selection down
+    // Move selection down (with wrap around)
-    if (selectedSettingIndex < settingsCount - 1) {
+    selectedSettingIndex = (selectedSettingIndex < settingsCount - 1) ? (selectedSettingIndex + 1) : 0;
-      selectedSettingIndex++;
     updateRequired = true;
   }
 }
-}
 
 void SettingsActivity::toggleCurrentSetting() {
   // Validate index
@@ -125,8 +128,25 @@ void SettingsActivity::toggleCurrentSetting() {
   } else if (setting.type == SettingType::ENUM && setting.valuePtr != nullptr) {
     const uint8_t currentValue = SETTINGS.*(setting.valuePtr);
     SETTINGS.*(setting.valuePtr) = (currentValue + 1) % static_cast<uint8_t>(setting.enumValues.size());
+  } else if (setting.type == SettingType::VALUE && setting.valuePtr != nullptr) {
+    // Decreasing would also be nice for large ranges I think but oh well can't have everything
+    const int8_t currentValue = SETTINGS.*(setting.valuePtr);
+    // Wrap to minValue if exceeding setting value boundary
+    if (currentValue + setting.valueRange.step > setting.valueRange.max) {
+      SETTINGS.*(setting.valuePtr) = setting.valueRange.min;
+    } else {
+      SETTINGS.*(setting.valuePtr) = currentValue + setting.valueRange.step;
+    }
   } else if (setting.type == SettingType::ACTION) {
-    if (std::string(setting.name) == "Check for updates") {
+    if (strcmp(setting.name, "Calibre Settings") == 0) {
+      xSemaphoreTake(renderingMutex, portMAX_DELAY);
+      exitActivity();
+      enterNewActivity(new CalibreSettingsActivity(renderer, mappedInput, [this] {
+        exitActivity();
+        updateRequired = true;
+      }));
+      xSemaphoreGive(renderingMutex);
+    } else if (strcmp(setting.name, "Check for updates") == 0) {
       xSemaphoreTake(renderingMutex, portMAX_DELAY);
       exitActivity();
       enterNewActivity(new OtaUpdateActivity(renderer, mappedInput, [this] {
@@ -163,7 +183,7 @@ void SettingsActivity::render() const {
   const auto pageHeight = renderer.getScreenHeight();
 
   // Draw header
-  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Settings", true, BOLD);
+  renderer.drawCenteredText(UI_12_FONT_ID, 15, "Settings", true, EpdFontFamily::BOLD);
 
   // Draw selection
   renderer.fillRect(0, 60 + selectedSettingIndex * 30 - 2, pageWidth - 1, 30);
@@ -183,6 +203,8 @@ void SettingsActivity::render() const {
     } else if (settingsList[i].type == SettingType::ENUM && settingsList[i].valuePtr != nullptr) {
       const uint8_t value = SETTINGS.*(settingsList[i].valuePtr);
       valueText = settingsList[i].enumValues[value];
+    } else if (settingsList[i].type == SettingType::VALUE && settingsList[i].valuePtr != nullptr) {
+      valueText = std::to_string(SETTINGS.*(settingsList[i].valuePtr));
     }
     const auto width = renderer.getTextWidth(UI_10_FONT_ID, valueText.c_str());
     renderer.drawText(UI_10_FONT_ID, pageWidth - 20 - width, settingY, valueText.c_str(), i != selectedSettingIndex);

src/activities/settings/SettingsActivity.h

@@ -11,14 +11,37 @@
 
 class CrossPointSettings;
 
-enum class SettingType { TOGGLE, ENUM, ACTION };
+enum class SettingType { TOGGLE, ENUM, ACTION, VALUE };
 
 // Structure to hold setting information
 struct SettingInfo {
   const char* name;                        // Display name of the setting
   SettingType type;                        // Type of setting
-  uint8_t CrossPointSettings::* valuePtr;  // Pointer to member in CrossPointSettings (for TOGGLE/ENUM)
+  uint8_t CrossPointSettings::* valuePtr;  // Pointer to member in CrossPointSettings (for TOGGLE/ENUM/VALUE)
   std::vector<std::string> enumValues;
+
+  struct ValueRange {
+    uint8_t min;
+    uint8_t max;
+    uint8_t step;
+  };
+  // Bounds/step for VALUE type settings
+  ValueRange valueRange;
+
+  // Static constructors
+  static SettingInfo Toggle(const char* name, uint8_t CrossPointSettings::* ptr) {
+    return {name, SettingType::TOGGLE, ptr};
+  }
+
+  static SettingInfo Enum(const char* name, uint8_t CrossPointSettings::* ptr, std::vector<std::string> values) {
+    return {name, SettingType::ENUM, ptr, std::move(values)};
+  }
+
+  static SettingInfo Action(const char* name) { return {name, SettingType::ACTION, nullptr}; }
+
+  static SettingInfo Value(const char* name, uint8_t CrossPointSettings::* ptr, const ValueRange valueRange) {
+    return {name, SettingType::VALUE, ptr, {}, valueRange};
+  }
 };
 
 class SettingsActivity final : public ActivityWithSubactivity {

src/activities/util/FullScreenMessageActivity.h

@@ -9,12 +9,12 @@
 
 class FullScreenMessageActivity final : public Activity {
   std::string text;
-  EpdFontStyle style;
+  EpdFontFamily::Style style;
   EInkDisplay::RefreshMode refreshMode;
 
  public:
   explicit FullScreenMessageActivity(GfxRenderer& renderer, MappedInputManager& mappedInput, std::string text,
-                                     const EpdFontStyle style = REGULAR,
+                                     const EpdFontFamily::Style style = EpdFontFamily::REGULAR,
                                      const EInkDisplay::RefreshMode refreshMode = EInkDisplay::FAST_REFRESH)
       : Activity("FullScreenMessage", renderer, mappedInput),
         text(std::move(text)),

src/activities/util/KeyboardEntryActivity.cpp

@@ -329,9 +329,13 @@ void KeyboardEntryActivity::render() const {
     }
   }
 
-  // Draw help text at absolute bottom of screen (consistent with other screens)
+  // Draw help text
-  const auto pageHeight = renderer.getScreenHeight();
+  const auto labels = mappedInput.mapLabels("« Back", "Select", "Left", "Right");
-  renderer.drawText(SMALL_FONT_ID, 10, pageHeight - 30, "Navigate: D-pad | Select: OK | Cancel: BACK");
+  renderer.drawButtonHints(UI_10_FONT_ID, labels.btn1, labels.btn2, labels.btn3, labels.btn4);
+
+  // Draw side button hints for Up/Down navigation
+  renderer.drawSideButtonHints(UI_10_FONT_ID, "Up", "Down");
+
   renderer.displayBuffer();
 }
 

src/main.cpp

@@ -7,12 +7,15 @@
 #include <SPI.h>
 #include <builtinFonts/all.h>
 
+#include <cstring>
+
 #include "Battery.h"
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "MappedInputManager.h"
 #include "activities/boot_sleep/BootActivity.h"
 #include "activities/boot_sleep/SleepActivity.h"
+#include "activities/browser/OpdsBookBrowserActivity.h"
 #include "activities/home/HomeActivity.h"
 #include "activities/network/CrossPointWebServerActivity.h"
 #include "activities/reader/ReaderActivity.h"
@@ -126,8 +129,6 @@ EpdFont ui12RegularFont(&ubuntu_12_regular);
 EpdFont ui12BoldFont(&ubuntu_12_bold);
 EpdFontFamily ui12FontFamily(&ui12RegularFont, &ui12BoldFont);
 
-// Auto-sleep timeout (10 minutes of inactivity)
-constexpr unsigned long AUTO_SLEEP_TIMEOUT_MS = 10 * 60 * 1000;
 // measurement of power button press duration calibration value
 unsigned long t1 = 0;
 unsigned long t2 = 0;
@@ -150,9 +151,11 @@ void verifyWakeupLongPress() {
   // Give the user up to 1000ms to start holding the power button, and must hold for SETTINGS.getPowerButtonDuration()
   const auto start = millis();
   bool abort = false;
-  // It takes us some time to wake up from deep sleep, so we need to subtract that from the duration
+  // Subtract the current time, because inputManager only starts counting the HeldTime from the first update()
-  uint16_t calibration = 29;
+  // This way, we remove the time we already took to reach here from the duration,
-  uint16_t calibratedPressDuration =
+  // assuming the button was held until now from millis()==0 (i.e. device start time).
+  const uint16_t calibration = start;
+  const uint16_t calibratedPressDuration =
       (calibration < SETTINGS.getPowerButtonDuration()) ? SETTINGS.getPowerButtonDuration() - calibration : 1;
 
   inputManager.update();
@@ -222,10 +225,15 @@ void onGoToSettings() {
   enterNewActivity(new SettingsActivity(renderer, mappedInputManager, onGoHome));
 }
 
+void onGoToBrowser() {
+  exitActivity();
+  enterNewActivity(new OpdsBookBrowserActivity(renderer, mappedInputManager, onGoHome));
+}
+
 void onGoHome() {
   exitActivity();
   enterNewActivity(new HomeActivity(renderer, mappedInputManager, onContinueReading, onGoToReaderHome, onGoToSettings,
-                                    onGoToFileTransfer));
+                                    onGoToFileTransfer, onGoToBrowser));
 }
 
 void setupDisplayAndFonts() {
@@ -271,7 +279,7 @@ void setup() {
     Serial.printf("[%lu] [   ] SD card initialization failed\n", millis());
     setupDisplayAndFonts();
     exitActivity();
-    enterNewActivity(new FullScreenMessageActivity(renderer, mappedInputManager, "SD card error", BOLD));
+    enterNewActivity(new FullScreenMessageActivity(renderer, mappedInputManager, "SD card error", EpdFontFamily::BOLD));
     return;
   }
 
@@ -316,14 +324,16 @@ void loop() {
     lastMemPrint = millis();
   }
 
-  // Check for any user activity (button press or release)
+  // Check for any user activity (button press or release) or active background work
   static unsigned long lastActivityTime = millis();
-  if (inputManager.wasAnyPressed() || inputManager.wasAnyReleased()) {
+  if (inputManager.wasAnyPressed() || inputManager.wasAnyReleased() ||
+      (currentActivity && currentActivity->preventAutoSleep())) {
     lastActivityTime = millis();  // Reset inactivity timer
   }
 
-  if (millis() - lastActivityTime >= AUTO_SLEEP_TIMEOUT_MS) {
+  const unsigned long sleepTimeoutMs = SETTINGS.getSleepTimeoutMs();
-    Serial.printf("[%lu] [SLP] Auto-sleep triggered after %lu ms of inactivity\n", millis(), AUTO_SLEEP_TIMEOUT_MS);
+  if (millis() - lastActivityTime >= sleepTimeoutMs) {
+    Serial.printf("[%lu] [SLP] Auto-sleep triggered after %lu ms of inactivity\n", millis(), sleepTimeoutMs);
     enterDeepSleep();
     // This should never be hit as `enterDeepSleep` calls esp_deep_sleep_start
     return;

src/network/CrossPointWebServer.cpp

@@ -194,7 +194,7 @@ void CrossPointWebServer::scanFiles(const char* path, const std::function<void(F
   Serial.printf("[%lu] [WEB] Scanning files in: %s\n", millis(), path);
 
   FsFile file = root.openNextFile();
-  char name[128];
+  char name[500];
   while (file) {
     file.getName(name, sizeof(name));
     auto fileName = String(name);

src/network/HttpDownloader.cpp

@@ -0,0 +1,128 @@
+#include "HttpDownloader.h"
+
+#include <HTTPClient.h>
+#include <HardwareSerial.h>
+#include <WiFiClientSecure.h>
+
+#include <memory>
+
+bool HttpDownloader::fetchUrl(const std::string& url, std::string& outContent) {
+  const std::unique_ptr<WiFiClientSecure> client(new WiFiClientSecure());
+  client->setInsecure();
+  HTTPClient http;
+
+  Serial.printf("[%lu] [HTTP] Fetching: %s\n", millis(), url.c_str());
+
+  http.begin(*client, url.c_str());
+  http.setFollowRedirects(HTTPC_STRICT_FOLLOW_REDIRECTS);
+  http.addHeader("User-Agent", "CrossPoint-ESP32-" CROSSPOINT_VERSION);
+
+  const int httpCode = http.GET();
+  if (httpCode != HTTP_CODE_OK) {
+    Serial.printf("[%lu] [HTTP] Fetch failed: %d\n", millis(), httpCode);
+    http.end();
+    return false;
+  }
+
+  outContent = http.getString().c_str();
+  http.end();
+
+  Serial.printf("[%lu] [HTTP] Fetched %zu bytes\n", millis(), outContent.size());
+  return true;
+}
+
+HttpDownloader::DownloadError HttpDownloader::downloadToFile(const std::string& url, const std::string& destPath,
+                                                             ProgressCallback progress) {
+  const std::unique_ptr<WiFiClientSecure> client(new WiFiClientSecure());
+  client->setInsecure();
+  HTTPClient http;
+
+  Serial.printf("[%lu] [HTTP] Downloading: %s\n", millis(), url.c_str());
+  Serial.printf("[%lu] [HTTP] Destination: %s\n", millis(), destPath.c_str());
+
+  http.begin(*client, url.c_str());
+  http.setFollowRedirects(HTTPC_STRICT_FOLLOW_REDIRECTS);
+  http.addHeader("User-Agent", "CrossPoint-ESP32-" CROSSPOINT_VERSION);
+
+  const int httpCode = http.GET();
+  if (httpCode != HTTP_CODE_OK) {
+    Serial.printf("[%lu] [HTTP] Download failed: %d\n", millis(), httpCode);
+    http.end();
+    return HTTP_ERROR;
+  }
+
+  const size_t contentLength = http.getSize();
+  Serial.printf("[%lu] [HTTP] Content-Length: %zu\n", millis(), contentLength);
+
+  // Remove existing file if present
+  if (SdMan.exists(destPath.c_str())) {
+    SdMan.remove(destPath.c_str());
+  }
+
+  // Open file for writing
+  FsFile file;
+  if (!SdMan.openFileForWrite("HTTP", destPath.c_str(), file)) {
+    Serial.printf("[%lu] [HTTP] Failed to open file for writing\n", millis());
+    http.end();
+    return FILE_ERROR;
+  }
+
+  // Get the stream for chunked reading
+  WiFiClient* stream = http.getStreamPtr();
+  if (!stream) {
+    Serial.printf("[%lu] [HTTP] Failed to get stream\n", millis());
+    file.close();
+    SdMan.remove(destPath.c_str());
+    http.end();
+    return HTTP_ERROR;
+  }
+
+  // Download in chunks
+  uint8_t buffer[DOWNLOAD_CHUNK_SIZE];
+  size_t downloaded = 0;
+  const size_t total = contentLength > 0 ? contentLength : 0;
+
+  while (http.connected() && (contentLength == 0 || downloaded < contentLength)) {
+    const size_t available = stream->available();
+    if (available == 0) {
+      delay(1);
+      continue;
+    }
+
+    const size_t toRead = available < DOWNLOAD_CHUNK_SIZE ? available : DOWNLOAD_CHUNK_SIZE;
+    const size_t bytesRead = stream->readBytes(buffer, toRead);
+
+    if (bytesRead == 0) {
+      break;
+    }
+
+    const size_t written = file.write(buffer, bytesRead);
+    if (written != bytesRead) {
+      Serial.printf("[%lu] [HTTP] Write failed: wrote %zu of %zu bytes\n", millis(), written, bytesRead);
+      file.close();
+      SdMan.remove(destPath.c_str());
+      http.end();
+      return FILE_ERROR;
+    }
+
+    downloaded += bytesRead;
+
+    if (progress && total > 0) {
+      progress(downloaded, total);
+    }
+  }
+
+  file.close();
+  http.end();
+
+  Serial.printf("[%lu] [HTTP] Downloaded %zu bytes\n", millis(), downloaded);
+
+  // Verify download size if known
+  if (contentLength > 0 && downloaded != contentLength) {
+    Serial.printf("[%lu] [HTTP] Size mismatch: got %zu, expected %zu\n", millis(), downloaded, contentLength);
+    SdMan.remove(destPath.c_str());
+    return HTTP_ERROR;
+  }
+
+  return OK;
+}

src/network/HttpDownloader.h

@@ -0,0 +1,42 @@
+#pragma once
+#include <SDCardManager.h>
+
+#include <functional>
+#include <string>
+
+/**
+ * HTTP client utility for fetching content and downloading files.
+ * Wraps WiFiClientSecure and HTTPClient for HTTPS requests.
+ */
+class HttpDownloader {
+ public:
+  using ProgressCallback = std::function<void(size_t downloaded, size_t total)>;
+
+  enum DownloadError {
+    OK = 0,
+    HTTP_ERROR,
+    FILE_ERROR,
+    ABORTED,
+  };
+
+  /**
+   * Fetch text content from a URL.
+   * @param url The URL to fetch
+   * @param outContent The fetched content (output)
+   * @return true if fetch succeeded, false on error
+   */
+  static bool fetchUrl(const std::string& url, std::string& outContent);
+
+  /**
+   * Download a file to the SD card.
+   * @param url The URL to download
+   * @param destPath The destination path on SD card
+   * @param progress Optional progress callback
+   * @return DownloadError indicating success or failure type
+   */
+  static DownloadError downloadToFile(const std::string& url, const std::string& destPath,
+                                      ProgressCallback progress = nullptr);
+
+ private:
+  static constexpr size_t DOWNLOAD_CHUNK_SIZE = 1024;
+};

src/network/OtaUpdater.cpp

@@ -3,7 +3,6 @@
 #include <ArduinoJson.h>
 #include <HTTPClient.h>
 #include <Update.h>
-#include <WiFiClientSecure.h>
 
 namespace {
 constexpr char latestReleaseUrl[] = "https://api.github.com/repos/daveallie/crosspoint-reader/releases/latest";
@@ -69,44 +68,41 @@ OtaUpdater::OtaUpdaterError OtaUpdater::checkForUpdate() {
   return OK;
 }
 
-bool OtaUpdater::isUpdateNewer() {
+bool OtaUpdater::isUpdateNewer() const {
   if (!updateAvailable || latestVersion.empty() || latestVersion == CROSSPOINT_VERSION) {
     return false;
   }
 
+  int currentMajor, currentMinor, currentPatch;
+  int latestMajor, latestMinor, latestPatch;
+
+  const auto currentVersion = CROSSPOINT_VERSION;
+
   // semantic version check (only match on 3 segments)
-  const auto updateMajor = stoi(latestVersion.substr(0, latestVersion.find('.')));
+  sscanf(latestVersion.c_str(), "%d.%d.%d", &latestMajor, &latestMinor, &latestPatch);
-  const auto updateMinor = stoi(
+  sscanf(currentVersion, "%d.%d.%d", &currentMajor, &currentMinor, &currentPatch);
-      latestVersion.substr(latestVersion.find('.') + 1, latestVersion.find_last_of('.') - latestVersion.find('.') - 1));
-  const auto updatePatch = stoi(latestVersion.substr(latestVersion.find_last_of('.') + 1));
 
-  std::string currentVersion = CROSSPOINT_VERSION;
+  /*
-  const auto currentMajor = stoi(currentVersion.substr(0, currentVersion.find('.')));
+   * Compare major versions.
-  const auto currentMinor = stoi(currentVersion.substr(
+   * If they differ, return true if latest major version greater than current major version
-      currentVersion.find('.') + 1, currentVersion.find_last_of('.') - currentVersion.find('.') - 1));
+   * otherwise return false.
-  const auto currentPatch = stoi(currentVersion.substr(currentVersion.find_last_of('.') + 1));
+   */
+  if (latestMajor != currentMajor) return latestMajor > currentMajor;
 
-  if (updateMajor > currentMajor) {
+  /*
-    return true;
+   * Compare minor versions.
-  }
+   * If they differ, return true if latest minor version greater than current minor version
-  if (updateMajor < currentMajor) {
+   * otherwise return false.
-    return false;
+   */
+  if (latestMinor != currentMinor) return latestMinor > currentMinor;
+
+  /*
+   * Check patch versions.
+   */
+  return latestPatch > currentPatch;
 }
 
-  if (updateMinor > currentMinor) {
+const std::string& OtaUpdater::getLatestVersion() const { return latestVersion; }
-    return true;
-  }
-  if (updateMinor < currentMinor) {
-    return false;
-  }
-
-  if (updatePatch > currentPatch) {
-    return true;
-  }
-  return false;
-}
-
-const std::string& OtaUpdater::getLatestVersion() { return latestVersion; }
 
 OtaUpdater::OtaUpdaterError OtaUpdater::installUpdate(const std::function<void(size_t, size_t)>& onProgress) {
   if (!isUpdateNewer()) {

src/network/OtaUpdater.h

@@ -23,8 +23,8 @@ class OtaUpdater {
   size_t totalSize = 0;
 
   OtaUpdater() = default;
-  bool isUpdateNewer();
+  bool isUpdateNewer() const;
-  const std::string& getLatestVersion();
+  const std::string& getLatestVersion() const;
   OtaUpdaterError checkForUpdate();
   OtaUpdaterError installUpdate(const std::function<void(size_t, size_t)>& onProgress);
 };

src/network/html/FilesPage.html

@@ -341,6 +341,90 @@
       width: 60px;
       text-align: center;
     }
+    /* Failed uploads banner */
+    .failed-uploads-banner {
+      background-color: #fff3cd;
+      border: 1px solid #ffc107;
+      border-radius: 4px;
+      padding: 15px;
+      margin-bottom: 15px;
+      display: none;
+    }
+    .failed-uploads-banner.show {
+      display: block;
+    }
+    .failed-uploads-header {
+      display: flex;
+      justify-content: space-between;
+      align-items: center;
+      margin-bottom: 10px;
+    }
+    .failed-uploads-title {
+      font-weight: 600;
+      color: #856404;
+      margin: 0;
+    }
+    .dismiss-btn {
+      background: none;
+      border: none;
+      font-size: 1.2em;
+      cursor: pointer;
+      color: #856404;
+      padding: 0;
+      line-height: 1;
+    }
+    .dismiss-btn:hover {
+      color: #533f03;
+    }
+    .failed-file-item {
+      display: flex;
+      justify-content: space-between;
+      align-items: center;
+      padding: 8px 0;
+      border-bottom: 1px solid #ffe69c;
+    }
+    .failed-file-item:last-child {
+      border-bottom: none;
+    }
+    .failed-file-info {
+      flex: 1;
+    }
+    .failed-file-name {
+      font-weight: 500;
+      color: #856404;
+    }
+    .failed-file-error {
+      font-size: 0.85em;
+      color: #856404;
+      opacity: 0.8;
+    }
+    .retry-btn {
+      background-color: #ffc107;
+      color: #533f03;
+      border: none;
+      padding: 6px 12px;
+      border-radius: 4px;
+      cursor: pointer;
+      font-size: 0.9em;
+      font-weight: 600;
+    }
+    .retry-btn:hover {
+      background-color: #e0a800;
+    }
+    .retry-all-btn {
+      background-color: #ffc107;
+      color: #533f03;
+      border: none;
+      padding: 8px 16px;
+      border-radius: 4px;
+      cursor: pointer;
+      font-size: 0.95em;
+      font-weight: 600;
+      margin-top: 10px;
+    }
+    .retry-all-btn:hover {
+      background-color: #e0a800;
+    }
     /* Delete modal */
     .delete-warning {
       color: #e74c3c;
@@ -505,6 +589,16 @@
   </div>
 </div>
 
+<!-- Failed Uploads Banner -->
+<div class="failed-uploads-banner" id="failedUploadsBanner">
+  <div class="failed-uploads-header">
+    <h3 class="failed-uploads-title">⚠️ Some files failed to upload</h3>
+    <button class="dismiss-btn" onclick="dismissFailedUploads()" title="Dismiss">&times;</button>
+  </div>
+  <div id="failedFilesList"></div>
+  <button class="retry-all-btn" onclick="retryAllFailedUploads()">Retry All Failed Uploads</button>
+</div>
+
 <div class="card">
   <div class="contents-header">
     <h2 class="contents-title">Contents</h2>
@@ -531,7 +625,7 @@
     <h3>📤 Upload file</h3>
     <div class="upload-form">
       <p class="file-info">Select a file to upload to <strong id="uploadPathDisplay"></strong></p>
-      <input type="file" id="fileInput" onchange="validateFile()">
+      <input type="file" id="fileInput" onchange="validateFile()" multiple>
       <button id="uploadBtn" class="upload-btn" onclick="uploadFile()" disabled>Upload</button>
       <div id="progress-container">
         <div id="progress-bar"><div id="progress-fill"></div></div>
@@ -717,22 +811,21 @@
   function validateFile() {
     const fileInput = document.getElementById('fileInput');
     const uploadBtn = document.getElementById('uploadBtn');
-    const file = fileInput.files[0];
+    const files = fileInput.files;
-    uploadBtn.disabled = !file;
+    uploadBtn.disabled = !(files.length > 0);
   }
 
+let failedUploadsGlobal = [];
+
 function uploadFile() {
   const fileInput = document.getElementById('fileInput');
-    const file = fileInput.files[0];
+  const files = Array.from(fileInput.files);
 
-    if (!file) {
+  if (files.length === 0) {
-      alert('Please select a file first!');
+    alert('Please select at least one file!');
     return;
   }
 
-    const formData = new FormData();
-    formData.append('file', file);
-
   const progressContainer = document.getElementById('progress-container');
   const progressFill = document.getElementById('progress-fill');
   const progressText = document.getElementById('progress-text');
@@ -741,41 +834,160 @@
   progressContainer.style.display = 'block';
   uploadBtn.disabled = true;
 
+  let currentIndex = 0;
+  const failedFiles = [];
+
+  function uploadNextFile() {
+    if (currentIndex >= files.length) {
+      // All files processed - show summary
+      if (failedFiles.length === 0) {
+        progressFill.style.backgroundColor = '#4caf50';
+        progressText.textContent = 'All uploads complete!';
+        setTimeout(() => {
+          closeUploadModal();
+          hydrate(); // Refresh file list instead of reloading
+        }, 1000);
+      } else {
+        progressFill.style.backgroundColor = '#e74c3c';
+        const failedList = failedFiles.map(f => f.name).join(', ');
+        progressText.textContent = `${files.length - failedFiles.length}/${files.length} uploaded. Failed: ${failedList}`;
+        
+        // Store failed files globally and show banner
+        failedUploadsGlobal = failedFiles;
+        
+        setTimeout(() => {
+          closeUploadModal();
+          showFailedUploadsBanner();
+          hydrate(); // Refresh file list to show successfully uploaded files
+        }, 2000);
+      }
+      return;
+    }
+
+    const file = files[currentIndex];
+    const formData = new FormData();
+    formData.append('file', file);
+
     const xhr = new XMLHttpRequest();
     // Include path as query parameter since multipart form data doesn't make
     // form fields available until after file upload completes
     xhr.open('POST', '/upload?path=' + encodeURIComponent(currentPath), true);
 
+    progressFill.style.width = '0%';
+    progressFill.style.backgroundColor = '#4caf50';
+    progressText.textContent = `Uploading ${file.name} (${currentIndex + 1}/${files.length})`;
+
     xhr.upload.onprogress = function (e) {
       if (e.lengthComputable) {
         const percent = Math.round((e.loaded / e.total) * 100);
         progressFill.style.width = percent + '%';
-        progressText.textContent = 'Uploading: ' + percent + '%';
+        progressText.textContent =
+          `Uploading ${file.name} (${currentIndex + 1}/${files.length}) — ${percent}%`;
       }
     };
 
     xhr.onload = function () {
       if (xhr.status === 200) {
-        progressText.textContent = 'Upload complete!';
+        currentIndex++;
-        setTimeout(function() {
+        uploadNextFile(); // upload next file
-          window.location.reload();
-        }, 1000);
       } else {
-        progressText.textContent = 'Upload failed: ' + xhr.responseText;
+        // Track failure and continue with next file
-        progressFill.style.backgroundColor = '#e74c3c';
+        failedFiles.push({ name: file.name, error: xhr.responseText, file: file });
-        uploadBtn.disabled = false;
+        currentIndex++;
+        uploadNextFile();
       }
     };
 
     xhr.onerror = function () {
-      progressText.textContent = 'Upload failed - network error';
+      // Track network error and continue with next file
-      progressFill.style.backgroundColor = '#e74c3c';
+      failedFiles.push({ name: file.name, error: 'network error', file: file });
-      uploadBtn.disabled = false;
+      currentIndex++;
+      uploadNextFile();
     };
 
     xhr.send(formData);
   }
 
+  uploadNextFile();
+}
+
+function showFailedUploadsBanner() {
+  const banner = document.getElementById('failedUploadsBanner');
+  const filesList = document.getElementById('failedFilesList');
+  
+  filesList.innerHTML = '';
+  
+  failedUploadsGlobal.forEach((failedFile, index) => {
+    const item = document.createElement('div');
+    item.className = 'failed-file-item';
+    item.innerHTML = `
+      <div class="failed-file-info">
+        <div class="failed-file-name">📄 ${escapeHtml(failedFile.name)}</div>
+        <div class="failed-file-error">Error: ${escapeHtml(failedFile.error)}</div>
+      </div>
+      <button class="retry-btn" onclick="retrySingleUpload(${index})">Retry</button>
+    `;
+    filesList.appendChild(item);
+  });
+  
+  // Ensure retry all button is visible
+  const retryAllBtn = banner.querySelector('.retry-all-btn');
+  if (retryAllBtn) retryAllBtn.style.display = '';
+  
+  banner.classList.add('show');
+}
+
+function dismissFailedUploads() {
+  const banner = document.getElementById('failedUploadsBanner');
+  banner.classList.remove('show');
+  failedUploadsGlobal = [];
+}
+
+function retrySingleUpload(index) {
+  const failedFile = failedUploadsGlobal[index];
+  if (!failedFile) return;
+  
+  // Create a DataTransfer to set the file input
+  const dt = new DataTransfer();
+  dt.items.add(failedFile.file);
+  
+  const fileInput = document.getElementById('fileInput');
+  fileInput.files = dt.files;
+  
+  // Remove this file from failed list
+  failedUploadsGlobal.splice(index, 1);
+  
+  // If no more failed files, hide banner
+  if (failedUploadsGlobal.length === 0) {
+    dismissFailedUploads();
+  }
+  
+  // Open modal and trigger upload
+  openUploadModal();
+  validateFile();
+}
+
+function retryAllFailedUploads() {
+  if (failedUploadsGlobal.length === 0) return;
+  
+  // Create a DataTransfer with all failed files
+  const dt = new DataTransfer();
+  failedUploadsGlobal.forEach(failedFile => {
+    dt.items.add(failedFile.file);
+  });
+  
+  const fileInput = document.getElementById('fileInput');
+  fileInput.files = dt.files;
+  
+  // Clear failed files list
+  failedUploadsGlobal = [];
+  dismissFailedUploads();
+  
+  // Open modal and trigger upload
+  openUploadModal();
+  validateFile();
+}
+
   function createFolder() {
     const folderName = document.getElementById('folderName').value.trim();
 

src/util/StringUtils.cpp

@@ -0,0 +1,52 @@
+#include "StringUtils.h"
+
+#include <cstring>
+
+namespace StringUtils {
+
+std::string sanitizeFilename(const std::string& name, size_t maxLength) {
+  std::string result;
+  result.reserve(name.size());
+
+  for (char c : name) {
+    // Replace invalid filename characters with underscore
+    if (c == '/' || c == '\\' || c == ':' || c == '*' || c == '?' || c == '"' || c == '<' || c == '>' || c == '|') {
+      result += '_';
+    } else if (c >= 32 && c < 127) {
+      // Keep printable ASCII characters
+      result += c;
+    }
+    // Skip non-printable characters
+  }
+
+  // Trim leading/trailing spaces and dots
+  size_t start = result.find_first_not_of(" .");
+  if (start == std::string::npos) {
+    return "book";  // Fallback if name is all invalid characters
+  }
+  size_t end = result.find_last_not_of(" .");
+  result = result.substr(start, end - start + 1);
+
+  // Limit filename length
+  if (result.length() > maxLength) {
+    result.resize(maxLength);
+  }
+
+  return result.empty() ? "book" : result;
+}
+
+bool checkFileExtension(const std::string& fileName, const char* extension) {
+  if (fileName.length() < strlen(extension)) {
+    return false;
+  }
+
+  const std::string fileExt = fileName.substr(fileName.length() - strlen(extension));
+  for (size_t i = 0; i < fileExt.length(); i++) {
+    if (tolower(fileExt[i]) != tolower(extension[i])) {
+      return false;
+    }
+  }
+  return true;
+}
+
+}  // namespace StringUtils

src/util/StringUtils.h

@@ -0,0 +1,19 @@
+#pragma once
+
+#include <string>
+
+namespace StringUtils {
+
+/**
+ * Sanitize a string for use as a filename.
+ * Replaces invalid characters with underscores, trims spaces/dots,
+ * and limits length to maxLength characters.
+ */
+std::string sanitizeFilename(const std::string& name, size_t maxLength = 100);
+
+/**
+ * Check if the given filename ends with the specified extension (case-insensitive).
+ */
+bool checkFileExtension(const std::string& fileName, const char* extension);
+
+}  // namespace StringUtils

src/util/UrlUtils.cpp

@@ -0,0 +1,41 @@
+#include "UrlUtils.h"
+
+namespace UrlUtils {
+
+std::string ensureProtocol(const std::string& url) {
+  if (url.find("://") == std::string::npos) {
+    return "http://" + url;
+  }
+  return url;
+}
+
+std::string extractHost(const std::string& url) {
+  const size_t protocolEnd = url.find("://");
+  if (protocolEnd == std::string::npos) {
+    // No protocol, find first slash
+    const size_t firstSlash = url.find('/');
+    return firstSlash == std::string::npos ? url : url.substr(0, firstSlash);
+  }
+  // Find the first slash after the protocol
+  const size_t hostStart = protocolEnd + 3;
+  const size_t pathStart = url.find('/', hostStart);
+  return pathStart == std::string::npos ? url : url.substr(0, pathStart);
+}
+
+std::string buildUrl(const std::string& serverUrl, const std::string& path) {
+  const std::string urlWithProtocol = ensureProtocol(serverUrl);
+  if (path.empty()) {
+    return urlWithProtocol;
+  }
+  if (path[0] == '/') {
+    // Absolute path - use just the host
+    return extractHost(urlWithProtocol) + path;
+  }
+  // Relative path - append to server URL
+  if (urlWithProtocol.back() == '/') {
+    return urlWithProtocol + path;
+  }
+  return urlWithProtocol + "/" + path;
+}
+
+}  // namespace UrlUtils

src/util/UrlUtils.h

@@ -0,0 +1,23 @@
+#pragma once
+#include <string>
+
+namespace UrlUtils {
+
+/**
+ * Prepend http:// if no protocol specified (server will redirect to https if needed)
+ */
+std::string ensureProtocol(const std::string& url);
+
+/**
+ * Extract host with protocol from URL (e.g., "http://example.com" from "http://example.com/path")
+ */
+std::string extractHost(const std::string& url);
+
+/**
+ * Build full URL from server URL and path.
+ * If path starts with /, it's an absolute path from the host root.
+ * Otherwise, it's relative to the server URL.
+ */
+std::string buildUrl(const std::string& serverUrl, const std::string& path);
+
+}  // namespace UrlUtils