crosspoint-reader-mod/USER_GUIDE.md

# CrossPoint User Guide

Welcome to the **CrossPoint** firmware. This guide outlines the hardware controls, navigation, and reading features of the device.

- [CrossPoint User Guide](#crosspoint-user-guide)
  - [1. Hardware Overview](#1-hardware-overview)
    - [Button Layout](#button-layout)
  - [2. Power \& Startup](#2-power--startup)
    - [Power On / Off](#power-on--off)
    - [First Launch](#first-launch)
  - [3. Screens](#3-screens)
    - [3.1 Home Screen](#31-home-screen)
    - [3.2 Reading Mode](#32-reading-mode)
    - [3.3 Browse Files Screen](#33-browse-files-screen)
    - [3.4 Recent Books Screen](#34-recent-books-screen)
    - [3.5 File Transfer Screen](#35-file-transfer-screen)
      - [3.5.1 Calibre Wireless Transfers](#351-calibre-wireless-transfers)
    - [3.6 Settings](#36-settings)
      - [3.6.1 Display](#361-display)
      - [3.6.2 Reader](#362-reader)
      - [3.6.3 Controls](#363-controls)
      - [3.6.4 System](#364-system)
      - [3.6.5 KOReader Sync Quick Setup](#365-koreader-sync-quick-setup)
    - [3.7 Sleep Screen](#37-sleep-screen)
  - [4. Reading Mode](#4-reading-mode)
    - [Page Turning](#page-turning)
    - [Chapter Navigation](#chapter-navigation)
    - [System Navigation](#system-navigation)
    - [Supported Languages](#supported-languages)
  - [5. Chapter Selection Screen](#5-chapter-selection-screen)
  - [6. Current Limitations \& Roadmap](#6-current-limitations--roadmap)
  - [7. Troubleshooting Issues \& Escaping Bootloop](#7-troubleshooting-issues--escaping-bootloop)


## 1. Hardware Overview

The device utilises the standard buttons on the Xteink 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**, **Reset** |

Button layout can be customized in the **[Controls Settings](#363-controls)**.

### Taking a Screenshot
When the Power Button and Volume Down button are pressed at the same time, it will take a screenshot and save it in the folder `screenshots/`.

Alternatively, while reading a book, press the **Confirm** button to open the reader menu and select **Take screenshot**.

---

## 2. Power & Startup

### Power On / Off

To turn the device on or off, **press and hold the Power button for approximately half a second**.
In the **[Controls Settings](#363-controls)** you can configure the power button to turn the device off with a short press instead of a long one.

To reboot the device (for example after a firmware update or if it's frozen), press and release the Reset button, and then quickly press and 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](#31-home-screen)** screen.

> [!NOTE]
> On subsequent restarts, the firmware will automatically reopen the last book you were reading.

---

## 3. Screens

### 3.1 Home 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, the **[Browse Files](#33-browse-files-screen)** screen, the **[Recent Books](#34-recent-books-screen)** screen, the **[File Transfer](#35-file-transfer-screen)** screen, or **[Settings](#36-settings)**.

### 3.2 Reading Mode

See [Reading Mode](#4-reading-mode) below for more information.

### 3.3 Browse Files Screen

The Browse Files screen acts as a file and folder browser.

* **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.
* **Open Selection:** Press **Confirm** to open a folder or read a selected book. 
* **Delete Files:** Hold and release **Confirm** to delete the selected file. You will be given an option to either confirm or cancel deletion. Folder deletion is not supported.

### 3.4 Recent Books Screen

The Recent Books screen lists the most recently opened books in a chronological view, displaying title and author.

### 3.5 File Transfer Screen

The File Transfer 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.

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.

### 3.5.1 Calibre Wireless Transfers

CrossPoint supports sending books from Calibre using the CrossPoint Reader device plugin.

1. Install the plugin in Calibre:
   - Head to https://github.com/crosspoint-reader/calibre-plugins/releases to download the latest version of the crosspoint_reader plugin.
   - Download the zip file.
   - Open Calibre → Preferences → Plugins → Load plugin from file → Select the zip file.
2. On the device: File Transfer → Connect to Calibre → Join a network.
3. Make sure your computer is on the same WiFi network.
4. In Calibre, click "Send to device" to transfer books.

### 3.6 Settings

The Settings screen allows you to configure the device's behavior. There are a few settings you can adjust:

#### 3.6.1 Display

- **Sleep Screen**: Which sleep screen to display when the device sleeps:
  - "Dark" (default) - The default dark Crosspoint logo sleep screen
  - "Light" - The same default sleep screen, on a white background
  - "Custom" - Custom images from the SD card; see [Sleep Screen](#37-sleep-screen) below for more information
  - "Cover" - The book cover image (Note: this is experimental and may not work as expected)
  - "None" - A blank screen
  - "Cover + Custom" - The book cover image, falls back to "Custom" behavior
- **Sleep Screen Cover Mode**: How to display the book cover when "Cover" sleep screen is selected:
  - "Fit" (default) - Scale the image down to fit centered on the screen, padding with white borders as necessary
  - "Crop" - Scale the image down and crop as necessary to try to fill the screen (Note: this is experimental and may not work as expected)
- **Sleep Screen Cover Filter**: What filter will be applied to the book cover when "Cover" sleep screen is selected:
  - "None" (default) - The cover image will be converted to a grayscale image and displayed as it is
  - "Contrast" - The image will be displayed as a black & white image without grayscale conversion
  - "Inverted" - The image will be inverted as in white & black and will be displayed without grayscale conversion
- **Status Bar**: Configure the status bar displayed while reading:
  - "None" - No status bar
  - "No Progress" - Show status bar without reading progress
  - "Full w/ Percentage" - Show status bar with book progress (as percentage)
  - "Full w/ Book Bar" - Show status bar with book progress (as bar)
  - "Book Bar Only" - Show book progress (as bar)
  - "Full w/ Chapter Bar" - Show status bar with chapter progress (as bar)
- **Hide Battery %**: Configure where to suppress the battery percentage display in the status bar; the battery icon will still be shown:
  - "Never" (default) - Always show battery percentage
  - "In Reader" - Show battery percentage everywhere except in reading mode
  - "Always" - Always hide battery percentage
- **Refresh Frequency**: Set how often the screen does a full refresh while reading to reduce ghosting; options are every 1, 5, 10, 15, or 30 pages.

- **UI Theme**: Set which UI theme to use:
  - "Classic" - The original Crosspoint theme
  - "Lyra" - The new theme for Crosspoint featuring rounded elements and menu icons
  - "Lyra Extended" - Lyra, but displays 3 books instead of 1 on the **[Home Screen](#31-home-screen)**
- **Sunlight Fading Fix**: Configure whether to enable a software-fix for the issue where white X4 models may fade when used in direct sunlight:
  - "OFF" (default) - Disable the fix
  - "ON" - Enable the fix

#### 3.6.2 Reader
- **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" (default), "Large", or "X Large".

- **Reader Line Spacing**: Adjust the spacing between lines; options are "Tight", "Normal" (default), or "Wide".
- **Reader Screen Margin**: Controls the screen margins in Reading Mode between 5 and 40 pixels in 5-pixel increments.
- **Reader Paragraph Alignment**: Set the alignment of paragraphs; options are "Justified" (default), "Left", "Center", or "Right".
- **Embedded Style**: Whether to use the EPUB file's embedded HTML and CSS stylisation and formatting; options are "ON" or "OFF".
- **Hyphenation**: Whether to hyphenate text in Reading Mode; options are "ON" or "OFF".
- **Reading Orientation**: Set the screen orientation for reading EPUB files:
  - "Portrait" (default) - Standard portrait orientation
  - "Landscape CW" - Landscape, rotated clockwise
  - "Inverted" - Portrait, upside down
  - "Landscape CCW" - Landscape, rotated counter-clockwise
- **Extra Paragraph Spacing**: Set how to handle paragraph breaks:
  - "ON" - Vertical space will be added between paragraphs in Reading Mode
  - "OFF" - Paragraphs will not have vertical space added, but will have first-line indentation
- **Text Anti-Aliasing**: Whether to show smooth grey edges (anti-aliasing) on text in reading mode. Note this slows down page turns slightly.

#### 3.6.3 Controls

- **Remap Front Buttons**: A menu for customising the function of each bottom edge button.
- **Side Button Layout (reader)**: Swap the order of the up and down volume buttons from "Prev/Next" (default) to "Next/Prev". This change is only in effect when reading.

- **Long-press Chapter Skip**: Set whether long-pressing page turn buttons skips to the next/previous chapter:
  - "Chapter Skip" (default) - Long-pressing skips to next/previous chapter
  - "Page Scroll" - Long-pressing scrolls a page up/down
- **Short Power Button Click**: Controls the effect of a short click of the power button:
  - "Ignore" (default) - Require a long press to turn off the device
  - "Sleep" - A short press puts the device into sleep mode
  - "Page Turn" - A short press in reading mode turns to the next page; a long press turns the device off

#### 3.6.4 System

- **Time to Sleep**: Set the duration of inactivity before the device automatically goes to sleep; options are 1, 5, 10 (default), 15 or 30 minutes.

- **WiFi Networks**: Connect to WiFi networks for file transfers and firmware updates.
- **KOReader Sync**: Options for setting up KOReader for syncing book progress.
- **OPDS Browser**: Configure OPDS server settings for browsing and downloading books. Set the server URL (for Calibre Content Server, add `/opds` to the end), and optionally configure username and password for servers requiring authentication. Note: Only HTTP Basic authentication is supported. If using Calibre Content Server with authentication enabled, you must set it to use Basic authentication instead of the default Digest authentication.
- **Clear Reading Cache**: Clear the internal SD card cache.
- **Check for updates**: Check for Crosspoint firmware updates over WiFi.
- **Language**: Set the system language (see **[Supported Languages](#supported-languages)** for more information).

#### 3.6.5 KOReader Sync Quick Setup

CrossPoint can sync reading progress with KOReader-compatible sync servers.
It also interoperates with KOReader apps/devices when they use the same server and credentials.

##### Option A: Free Public Server (`sync.koreader.rocks`)

1. Register a user once (only if needed):

```bash
USERNAME="user"
PASSWORD="pass"
PASSWORD_MD5="$(printf '%s' "$PASSWORD" | openssl md5 | awk '{print $2}')"

curl -i "https://sync.koreader.rocks/users/create" \
  -H "Accept: application/vnd.koreader.v1+json" \
  -H "Content-Type: application/json" \
  --data "{\"username\":\"$USERNAME\",\"password\":\"$PASSWORD_MD5\"}"
```

Already have KOReader Sync credentials? Skip registration; basic sync only requires using the same existing username/password on all devices.

When this returns `HTTP 402` with `{"code":2002,"message":"Username is already registered."}`, pick a different username or use that existing account.

2. On each CrossPoint device:
   - Go to **Settings -> System -> KOReader Sync**.
   - Set **Username** and **Password** (enter the plain password; CrossPoint computes MD5 internally, and use the same values on all devices).
   - Set **Sync Server URL** to `https://sync.koreader.rocks`, or leave it empty (both use the same default KOReader sync server).
   - Run **Authenticate**.

3. While reading, press **Confirm** to open the reader menu, then select **Sync Progress**.
   - Choose **Apply Remote** to jump to remote progress.
   - Choose **Upload Local** to push current progress.

##### Option B: Self-Hosted Server (Docker Compose)

1. Start a sync server:

```bash
mkdir -p kosync-quickstart
cd kosync-quickstart

cat > compose.yaml <<'YAML'
services:
  kosync:
    image: koreader/kosync:latest
    ports:
      - "7200:7200"
      - "17200:17200"
    volumes:
      - ./data/redis:/var/lib/redis
    environment:
      - ENABLE_USER_REGISTRATION=true
    restart: unless-stopped
YAML

# Docker
docker compose up -d

# Podman (alternative)
podman compose up -d
```

> [!NOTE]
> `ENABLE_USER_REGISTRATION=true` is convenient for first setup. After creating your users, set it to `false` (or remove it) to avoid unexpected registrations.

2. Verify the server:

```bash
curl -H "Accept: application/vnd.koreader.v1+json" "http://<server-ip>:17200/healthcheck"
# Expected: {"state":"OK"}
```

3. Register a user once.
CrossPoint authenticates against KOReader Sync (`koreader/kosync`) using an MD5 key, so register using the MD5 of your password:

> [!WARNING]
> Sending a reusable MD5-derived password over plain HTTP is insecure.
> Create unique sync-only credentials and do not reuse main account passwords.
> Prefer `https://<server-ip>:7200` whenever traffic leaves a fully trusted LAN or when using untrusted networks.
> Use `curl -k` only for self-signed certificate testing.

```bash
USERNAME="user"
PASSWORD="pass"
PASSWORD_MD5="$(printf '%s' "$PASSWORD" | openssl md5 | awk '{print $2}')"

curl -i "http://<server-ip>:17200/users/create" \
  -H "Accept: application/vnd.koreader.v1+json" \
  -H "Content-Type: application/json" \
  --data "{\"username\":\"$USERNAME\",\"password\":\"$PASSWORD_MD5\"}"
```

If this returns `HTTP 402` with `{"code":2002,"message":"Username is already registered."}`, the account already exists.

4. On each CrossPoint device:
   - Go to **Settings -> System -> KOReader Sync**.
   - Set **Username** and **Password** (enter the plain password; CrossPoint computes MD5 internally, and use the same values on all devices).
   - Set **Sync Server URL** to `http://<server-ip>:17200`.
   - Run **Authenticate**.

If you use the HTTPS listener, use `https://<server-ip>:7200` (`curl -k` only for self-signed certificate testing).

5. While reading, press **Confirm** to open the reader menu, then select **Sync Progress**.
   - Choose **Apply Remote** to jump to remote progress.
   - Choose **Upload Local** to push current progress.

### 3.7 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 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.

> [!NOTE]
> You'll need to set the **Sleep Screen** setting to **Custom** in order to use these images.

> [!TIP]
> For best results:
> - Use uncompressed BMP files with 24-bit color depth
> - Use a resolution of 480x800 pixels to match the device's screen resolution.

---

## 4. Reading Mode

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 the **[Controls Settings](#363-controls)**.

If the **Short Power Button Click** setting is set to "Page Turn", you can also turn to the next page by briefly pressing the Power button.

### 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.

This feature can be disabled in the **[Controls Settings](#363-controls)** to help avoid changing chapters by mistake.


### System Navigation
* **Return to Home:** Press the **Back** button to close the book and return to the **[Home](#31-home-screen)** screen.
* **Return to Browse Files:** Press and hold the **Back** button to close the book and return to the **[Browse Files](#33-browse-files-screen)** screen.
* **Chapter Menu:** Press **Confirm** to open the **[Table of Contents/Chapter Selection](#5-chapter-selection-screen)** screen.

### Supported Languages

CrossPoint renders text using the following Unicode character blocks, enabling support for a wide range of languages:

*   **Latin Script (Basic, Supplement, Extended-A):** Covers English, German, French, Spanish, Portuguese, Italian, Dutch, Swedish, Norwegian, Danish, Finnish, Polish, Czech, Hungarian, Romanian, Slovak, Slovenian, Turkish, and others.
*   **Cyrillic Script (Standard and Extended):** Covers Russian, Ukrainian, Belarusian, Bulgarian, Serbian, Macedonian, Kazakh, Kyrgyz, Mongolian, and others.

What is not supported: Chinese, Japanese, Korean, Vietnamese, Hebrew, Arabic, Greek and Farsi.

---

## 5. Chapter Selection Screen

Accessible by pressing **Confirm** while inside a book.

1.  Use **Left** (or **Volume Up**), or **Right** (or **Volume Down**) to highlight the desired chapter.
2.  Press **Confirm** to jump to that chapter.
3.  *Alternatively, press **Back** to cancel and return to your current page.*

---

## 6. Current Limitations & Roadmap

Please note that this firmware is currently in active development. The following features are **not yet supported** but are planned for future updates:

* **Images:** Embedded images in e-books will not render.
* **Cover Images:** Large cover images embedded into EPUB require several seconds (~10s for ~2000 pixel tall image) to convert for sleep screen and home screen thumbnail. Consider optimizing the EPUB with e.g. https://github.com/bigbag/epub-to-xtc-converter to speed this up.

---

## 7. Troubleshooting Issues & Escaping Bootloop

If an issue or crash is encountered while using Crosspoint, feel free to raise an issue ticket and attach the serial monitor logs. The logs can be obtained by connecting the device to a computer and starting a serial monitor. Either [Serial Monitor](https://www.serialmonitor.org/) or the following command can be used:

```
pio device monitor
```

If the device is stuck in a bootloop, press and release the Reset button. Then, press and hold on to the configured Back button and the Power Button to boot to the Home Screen.

There can be issues with broken cache or config. In this case, delete the `.crosspoint` directory on your SD card (or consider deleting only `settings.bin`, `state.bin`, or `epub_*` cache directories in the `.crosspoint/` folder).