From 127205de2e4acdc62e1fdb35a1be65eb96ccfe5a Mon Sep 17 00:00:00 2001
From: cottongin <cottongin@users.noreply.github.com>
Date: Mon, 3 Aug 2026 11:31:36 -0400
Subject: [PATCH] fix: suppress all e-ink refreshes during boot with
 setAutoDisplay(false)

Co-authored-by: Cursor <cursoragent@cursor.com>
---
 src/display_manager.cpp | 15 ++++++++++++---
 src/main.cpp            |  4 ++++
 2 files changed, 16 insertions(+), 3 deletions(-)

diff --git a/src/display_manager.cpp b/src/display_manager.cpp
index 4062699..8ffdc69 100644
--- a/src/display_manager.cpp
+++ b/src/display_manager.cpp
@@ -16,6 +16,9 @@ void DisplayManager::begin(PowerManager& power) {
     _power = &power;
     _display = &M5.Display;
 
+    // Ensure no automatic e-ink refreshes happen
+    _display->setAutoDisplay(false);
+
     // Set rotation for landscape (device physically rotated)
     _display->setRotation(3);
 
@@ -26,10 +29,11 @@ void DisplayManager::begin(PowerManager& power) {
 void DisplayManager::showSetupScreen() {
     _power->enableEPDPower();
 
+    // Batch all drawing — nothing hits the panel until display() at the end
+    _display->startWrite();
     _display->fillScreen(TFT_WHITE);
 
     // Generate QR code for WiFi auto-connect
-    // Format: WIFI:T:nopass;S:PaperColor-Setup;;
     const char* qrData = "WIFI:T:nopass;S:PaperColor-Setup;;";
     QRCode qrcode;
     uint8_t qrcodeData[qrcode_getBufferSize(6)];
@@ -37,7 +41,7 @@ void DisplayManager::showSetupScreen() {
 
     // Draw QR code centered vertically, left-of-center horizontally
     int qrSize = qrcode.size;
-    int scale = 4;  // pixels per QR module
+    int scale = 4;
     int qrPixels = qrSize * scale;
     int qrX = (DISPLAY_WIDTH / 3) - (qrPixels / 2);
     int qrY = (DISPLAY_HEIGHT - qrPixels) / 2;
@@ -49,7 +53,7 @@ void DisplayManager::showSetupScreen() {
         }
     }
 
-    // Draw text instructions to the right of QR code
+    // Text instructions to the right of QR code
     int textX = DISPLAY_WIDTH / 2 + 40;
     _display->setTextColor(TFT_BLACK);
     _display->setTextDatum(middle_left);
@@ -64,6 +68,9 @@ void DisplayManager::showSetupScreen() {
     _display->drawString("Then open:", textX, DISPLAY_HEIGHT / 2 + 70);
     _display->drawString("192.168.4.1", textX, DISPLAY_HEIGHT / 2 + 95);
 
+    _display->endWrite();
+
+    // Single e-ink refresh — the only panel update during boot
     triggerRefresh();
     _power->disableEPDPower();
 }
@@ -100,6 +107,7 @@ void DisplayManager::showImage(const ProcessedImage& img) {
 void DisplayManager::showMessage(const char* title, const char* body) {
     _power->enableEPDPower();
 
+    _display->startWrite();
     _display->fillScreen(TFT_WHITE);
     _display->setTextColor(TFT_BLACK);
     _display->setTextDatum(middle_center);
@@ -107,6 +115,7 @@ void DisplayManager::showMessage(const char* title, const char* body) {
     _display->drawString(title, DISPLAY_WIDTH / 2, DISPLAY_HEIGHT / 2 - 30);
     _display->setTextSize(1);
     _display->drawString(body, DISPLAY_WIDTH / 2, DISPLAY_HEIGHT / 2 + 20);
+    _display->endWrite();
 
     triggerRefresh();
     _power->disableEPDPower();
diff --git a/src/main.cpp b/src/main.cpp
index dfe5b88..17e10d5 100644
--- a/src/main.cpp
+++ b/src/main.cpp
@@ -173,8 +173,12 @@ void webActionCallback(const String& action) {
 
 void setup() {
     auto cfg = M5.config();
+    cfg.clear_display = false;  // Don't clear/refresh e-ink on init
     M5.begin(cfg);
 
+    // Prevent any automatic e-ink refreshes until we explicitly call display()
+    M5.Display.setAutoDisplay(false);
+
     Serial.begin(115200);
     Serial.println("[main] Immich Frame v1.0 booting...");