Added InkHUD style touch backlight control

src/input/ButtonThread.cpp

@@ -37,6 +37,9 @@ bool ButtonThread::initButton(const ButtonConfig &config)
     _activeLow = config.activeLow;
     _touchQuirk = config.touchQuirk;
     _intRoutine = config.intRoutine;
+    _pressHandler = config.onPress;
+    _releaseHandler = config.onRelease;
+    _suppressLeadUp = config.suppressLeadUpSound;
     _longLongPress = config.longLongPress;
 
     userButton = OneButton(config.pinNumber, config.activeLow, config.activePullup);
@@ -133,6 +136,8 @@ int32_t ButtonThread::runOnce()
 
     // Detect start of button press
     if (buttonCurrentlyPressed && !buttonWasPressed) {
+        if (_pressHandler)
+            _pressHandler();
         buttonPressStartTime = millis();
         leadUpPlayed = false;
         leadUpSequenceActive = false;
@@ -140,7 +145,7 @@ int32_t ButtonThread::runOnce()
     }
 
     // Progressive lead-up sound system
-    if (buttonCurrentlyPressed && (millis() - buttonPressStartTime) >= BUTTON_LEADUP_MS) {
+    if (!_suppressLeadUp && buttonCurrentlyPressed && (millis() - buttonPressStartTime) >= BUTTON_LEADUP_MS) {
 
         // Start the progressive sequence if not already active
         if (!leadUpSequenceActive) {
@@ -160,6 +165,8 @@ int32_t ButtonThread::runOnce()
 
     // Reset when button is released
     if (!buttonCurrentlyPressed && buttonWasPressed) {
+        if (_releaseHandler)
+            _releaseHandler();
         leadUpSequenceActive = false;
         resetLeadUpSequence();
     }

src/input/ButtonThread.h

@@ -13,6 +13,9 @@ struct ButtonConfig {
     bool activePullup = true;
     uint32_t pullupSense = 0;
     voidFuncPtr intRoutine = nullptr;
+    voidFuncPtr onPress = nullptr;   // Optional edge callbacks
+    voidFuncPtr onRelease = nullptr; // Optional edge callbacks
+    bool suppressLeadUpSound = false;
     input_broker_event singlePress = INPUT_BROKER_NONE;
     input_broker_event longPress = INPUT_BROKER_NONE;
     uint16_t longPressTime = 500;
@@ -94,6 +97,9 @@ class ButtonThread : public Observable<const InputEvent *>, public concurrency::
     input_broker_event _shortLong = INPUT_BROKER_NONE;
 
     voidFuncPtr _intRoutine = nullptr;
+    voidFuncPtr _pressHandler = nullptr;
+    voidFuncPtr _releaseHandler = nullptr;
+    bool _suppressLeadUp = false;
     uint16_t _longPressTime = 500;
     uint16_t _longLongPressTime = 3900;
     int _pinNum = 0;

src/main.cpp

@@ -107,6 +107,10 @@ NRF52Bluetooth *nrf52Bluetooth = nullptr;
 
 #if defined(BUTTON_PIN_TOUCH)
 ButtonThread *TouchButtonThread = nullptr;
+#if defined(TTGO_T_ECHO_PLUS) && defined(PIN_EINK_EN)
+static bool touchBacklightWasOn = false;
+static bool touchBacklightActive = false;
+#endif
 #endif
 
 #if defined(BUTTON_PIN) || defined(ARCH_PORTDUINO)
@@ -1043,6 +1047,24 @@ void setup()
     };
     touchConfig.singlePress = INPUT_BROKER_NONE;
     touchConfig.longPress = INPUT_BROKER_BACK;
+#if defined(TTGO_T_ECHO_PLUS) && defined(PIN_EINK_EN)
+    // On T-Echo Plus the touch pad should only drive the backlight, not UI navigation/sounds
+    touchConfig.longPress = INPUT_BROKER_NONE;
+    touchConfig.suppressLeadUpSound = true;
+    touchConfig.onPress = []() {
+        touchBacklightWasOn = uiconfig.screen_brightness == 1;
+        if (!touchBacklightWasOn) {
+            digitalWrite(PIN_EINK_EN, HIGH);
+        }
+        touchBacklightActive = true;
+    };
+    touchConfig.onRelease = []() {
+        if (touchBacklightActive && !touchBacklightWasOn) {
+            digitalWrite(PIN_EINK_EN, LOW);
+        }
+        touchBacklightActive = false;
+    };
+#endif
     TouchButtonThread->initButton(touchConfig);
 #endif