techo: display backlight behavior

examples/companion_radio/ui-new/UITask.cpp

@@ -519,6 +519,14 @@ void UITask::loop() {
     c = handleLongPress(KEY_ENTER);
   }
 #endif
+#if defined(DISP_BACKLIGHT) && defined(BACKLIGHT_BTN)
+  static int next_btn_check = 0;
+  if (millis() > next_btn_check) {
+    bool touch_state = digitalRead(PIN_BUTTON2);
+    digitalWrite(DISP_BACKLIGHT, !touch_state);
+    next_btn_check = millis() + 300;
+  }
+#endif
 
   if (c != 0 && curr) {
     curr->handleInput(c);

src/helpers/ui/GxEPDDisplay.cpp

@@ -19,6 +19,7 @@ bool GxEPDDisplay::begin() {
   display.fillScreen(GxEPD_WHITE);
   display.display(true);
   #if DISP_BACKLIGHT
+  digitalWrite(DISP_BACKLIGHT, LOW);
   pinMode(DISP_BACKLIGHT, OUTPUT);
   #endif
   _init = true;
@@ -27,14 +28,14 @@ bool GxEPDDisplay::begin() {
 
 void GxEPDDisplay::turnOn() {
   if (!_init) begin();
-#if DISP_BACKLIGHT
+#if defined(DISP_BACKLIGHT) && !defined(BACLIGHT_BTN)
   digitalWrite(DISP_BACKLIGHT, HIGH);
 #endif
   _isOn = true;
 }
 
 void GxEPDDisplay::turnOff() {
-#if DISP_BACKLIGHT
+#if defined(DISP_BACKLIGHT) && !defined(BACKLIGHT_BTN)
   digitalWrite(DISP_BACKLIGHT, LOW);
 #endif
   _isOn = false;

variants/techo/platformio.ini

@@ -78,6 +78,7 @@ build_flags =
   -D DISPLAY_CLASS=GxEPDDisplay
   -D OFFLINE_QUEUE_SIZE=256
   -D UI_RECENT_LIST_SIZE=9
+  -D BACKLIGHT_BTN=PIN_BUTTON2
 ;  -D MESH_PACKET_LOGGING=1
 ;  -D MESH_DEBUG=1
 build_src_filter = ${LilyGo_Techo.build_src_filter}