Updates to X3-specific display and power button handling

Centralize display initialization and power button verification for X3 devices

lib/hal/HalDisplay.cpp

@@ -7,7 +7,22 @@ HalDisplay::HalDisplay() : einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_R
 
 HalDisplay::~HalDisplay() {}
 
-void HalDisplay::begin() { einkDisplay.begin(); }
+void HalDisplay::begin() {
+  // Set X3-specific display dimensions before initializing
+  if (gpio.deviceIsX3()) {
+    einkDisplay.setDisplayDimensions(792, 528);
+  }
+
+  einkDisplay.begin();
+
+  // Request resync after specific wakeup events to ensure clean display state
+  const auto wakeupReason = gpio.getWakeupReason();
+  if (wakeupReason == HalGPIO::WakeupReason::PowerButton ||
+      wakeupReason == HalGPIO::WakeupReason::AfterFlash ||
+      wakeupReason == HalGPIO::WakeupReason::Other) {
+    einkDisplay.requestResync();
+  }
+}
 
 void HalDisplay::setDisplayDimensions(uint16_t width, uint16_t height) {
   einkDisplay.setDisplayDimensions(width, height);

lib/hal/HalGPIO.cpp

@@ -3,6 +3,9 @@
 #include <Wire.h>
 #include <esp_sleep.h>
 
+// Global HalGPIO instance
+HalGPIO gpio;
+
 void HalGPIO::begin() {
   inputMgr.begin();
   SPI.begin(EPD_SCLK, SPI_MISO, EPD_MOSI, EPD_CS);
@@ -21,9 +24,9 @@ void HalGPIO::begin() {
   // reconfigures the pin for I2C, so it must run last.
   if (_deviceType == DeviceType::X3) {
     Wire.begin(20, 0, 400000);
-    _useI2C = true;
+    _batteryUseI2C = true;
-    _i2cAddr = 0x55;
+    _batteryI2cAddr = 0x55;
-    _socRegister = 0x2C;
+    _batterySocRegister = 0x2C;
   }
 }
 
@@ -53,14 +56,60 @@ void HalGPIO::startDeepSleep() {
   esp_deep_sleep_start();
 }
 
+void HalGPIO::verifyPowerButtonWakeup(uint16_t requiredDurationMs, bool shortPressAllowed) {
+  if (shortPressAllowed) {
+    // Fast path - no duration check needed
+    return;
+  }
+
+  // Calibrate: subtract boot time already elapsed, assuming button held since boot
+  const uint16_t calibration = millis();
+  const uint16_t calibratedDuration = (calibration < requiredDurationMs) ? (requiredDurationMs - calibration) : 1;
+
+  if (deviceIsX3()) {
+    // X3: Direct GPIO read (inputMgr not yet reliable at this point)
+    const uint8_t powerPin = InputManager::POWER_BUTTON_PIN;
+    if (digitalRead(powerPin) != LOW) {
+      startDeepSleep();
+    }
+    const unsigned long holdStart = millis();
+    while (millis() - holdStart < calibratedDuration) {
+      if (digitalRead(powerPin) != LOW) {
+        startDeepSleep();
+      }
+      delay(5);
+    }
+  } else {
+    // X4: Use inputMgr with wait window for it to stabilize
+    const auto start = millis();
+    inputMgr.update();
+    // inputMgr.isPressed() may take up to ~500ms to return correct state
+    while (!inputMgr.isPressed(BTN_POWER) && millis() - start < 1000) {
+      delay(10);
+      inputMgr.update();
+    }
+    if (inputMgr.isPressed(BTN_POWER)) {
+      do {
+        delay(10);
+        inputMgr.update();
+      } while (inputMgr.isPressed(BTN_POWER) && inputMgr.getHeldTime() < calibratedDuration);
+      if (inputMgr.getHeldTime() < calibratedDuration) {
+        startDeepSleep();
+      }
+    } else {
+      startDeepSleep();
+    }
+  }
+}
+
 int HalGPIO::getBatteryPercentage() const {
-  if (_useI2C) {
+  if (_batteryUseI2C) {
     // Read SOC directly from I2C fuel gauge (16-bit LE register).
     // Returns 0 on I2C error so the UI shows 0% rather than crashing.
-    Wire.beginTransmission(_i2cAddr);
+    Wire.beginTransmission(_batteryI2cAddr);
-    Wire.write(_socRegister);
+    Wire.write(_batterySocRegister);
     if (Wire.endTransmission(false) != 0) return 0;
-    Wire.requestFrom(_i2cAddr, (uint8_t)2);
+    Wire.requestFrom(_batteryI2cAddr, (uint8_t)2);
     if (Wire.available() < 2) return 0;
     const uint8_t lo = Wire.read();
     const uint8_t hi = Wire.read();

lib/hal/HalGPIO.h

@@ -30,13 +30,18 @@ class HalGPIO {
   DeviceType _deviceType = DeviceType::X4;
   int _detectAdcValue = 0;
   int _batteryPin = BAT_GPIO0;
-  bool _useI2C = false;
+  // I2C fuel gauge configuration for X3 battery monitoring
-  uint8_t _i2cAddr = 0;
+  bool _batteryUseI2C = false;      // Whether to use I2C fuel gauge (X3) vs ADC (X4)
-  uint8_t _socRegister = 0;
+  uint8_t _batteryI2cAddr = 0;      // I2C address of fuel gauge chip
+  uint8_t _batterySocRegister = 0;  // Register address for state-of-charge
 
  public:
   HalGPIO() = default;
 
+  // Inline device type helpers for cleaner downstream checks
+  inline bool deviceIsX3() const { return _deviceType == DeviceType::X3; }
+  inline bool deviceIsX4() const { return _deviceType == DeviceType::X4; }
+
   // Start button GPIO and setup SPI for screen and SD card
   void begin();
 
@@ -52,6 +57,11 @@ class HalGPIO {
   // Setup wake up GPIO and enter deep sleep
   void startDeepSleep();
 
+  // Verify power button was held long enough after wakeup.
+  // If verification fails, enters deep sleep and does not return.
+  // Should only be called when wakeup reason is PowerButton.
+  void verifyPowerButtonWakeup(uint16_t requiredDurationMs, bool shortPressAllowed);
+
   // Get battery percentage (range 0-100)
   int getBatteryPercentage() const;
 

src/activities/reader/EpubReaderActivity.cpp

@@ -683,7 +683,7 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
     pagesUntilFullRefresh--;
   }
 
-  const bool useGrayscaleAA = SETTINGS.textAntiAliasing && gpio.getDeviceType() != HalGPIO::DeviceType::X3;
+  const bool useGrayscaleAA = SETTINGS.textAntiAliasing && !gpio.deviceIsX3();
   if (useGrayscaleAA) {
     // Save BW buffer only when we actually run grayscale passes.
     renderer.storeBwBuffer();

src/main.cpp

@@ -30,7 +30,6 @@
 #include "util/ButtonNavigator.h"
 
 HalDisplay display;
-HalGPIO gpio;
 MappedInputManager mappedInputManager(gpio);
 GfxRenderer renderer(display);
 Activity* currentActivity;
@@ -124,10 +123,6 @@ EpdFont ui12RegularFont(&ubuntu_12_regular);
 EpdFont ui12BoldFont(&ubuntu_12_bold);
 EpdFontFamily ui12FontFamily(&ui12RegularFont, &ui12BoldFont);
 
-// measurement of power button press duration calibration value
-unsigned long t1 = 0;
-unsigned long t2 = 0;
-
 void exitActivity() {
   if (currentActivity) {
     currentActivity->onExit();
@@ -141,50 +136,6 @@ void enterNewActivity(Activity* activity) {
   currentActivity->onEnter();
 }
 
-// Verify power button press duration on wake-up from deep sleep
-// Pre-condition: isWakeupByPowerButton() == true
-void verifyPowerButtonDuration() {
-  if (SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::SLEEP) {
-    // Fast path for short press
-    // Needed because inputManager.isPressed() may take up to ~500ms to return the correct state
-    return;
-  }
-
-  // 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;
-  // Subtract the current time, because inputManager only starts counting the HeldTime from the first update()
-  // This way, we remove the time we already took to reach here from the duration,
-  // 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;
-
-  gpio.update();
-  // Needed because inputManager.isPressed() may take up to ~500ms to return the correct state
-  while (!gpio.isPressed(HalGPIO::BTN_POWER) && millis() - start < 1000) {
-    delay(10);  // only wait 10ms each iteration to not delay too much in case of short configured duration.
-    gpio.update();
-  }
-
-  t2 = millis();
-  if (gpio.isPressed(HalGPIO::BTN_POWER)) {
-    do {
-      delay(10);
-      gpio.update();
-    } while (gpio.isPressed(HalGPIO::BTN_POWER) && gpio.getHeldTime() < calibratedPressDuration);
-    abort = gpio.getHeldTime() < calibratedPressDuration;
-  } else {
-    abort = true;
-  }
-
-  if (abort) {
-    // Button released too early. Returning to sleep.
-    // IMPORTANT: Re-arm the wakeup trigger before sleeping again
-    gpio.startDeepSleep();
-  }
-}
-
 void waitForPowerRelease() {
   gpio.update();
   while (gpio.isPressed(HalGPIO::BTN_POWER)) {
@@ -193,25 +144,6 @@ void waitForPowerRelease() {
   }
 }
 
-bool verifyPowerButtonDurationX3() {
-  // Match X4 semantics: require only the *remaining* hold time after boot.
-  // This avoids extra wake-delay windows and sleep/retry loops.
-  const uint16_t requiredHoldMs = SETTINGS.getPowerButtonDuration();
-  const uint16_t calibration = millis();
-  const uint16_t calibratedPressDuration = (calibration < requiredHoldMs) ? (requiredHoldMs - calibration) : 1;
-  const uint8_t powerPin = InputManager::POWER_BUTTON_PIN;
-
-  // Wake is already caused by power button; require it to still be held now.
-  if (digitalRead(powerPin) != LOW) return false;
-
-  const unsigned long holdStart = millis();
-  while (millis() - holdStart < calibratedPressDuration) {
-    if (digitalRead(powerPin) != LOW) return false;
-    delay(5);
-  }
-  return true;
-}
-
 // Enter deep sleep mode
 void enterDeepSleep() {
   APP_STATE.lastSleepFromReader = currentActivity && currentActivity->isReaderActivity();
@@ -221,7 +153,6 @@ void enterDeepSleep() {
   enterNewActivity(new SleepActivity(renderer, mappedInputManager));
 
   display.deepSleep();
-  LOG_DBG("MAIN", "Power button press calibration value: %lu ms", t2 - t1);
   LOG_DBG("MAIN", "Entering deep sleep");
 
   gpio.startDeepSleep();
@@ -277,9 +208,6 @@ void onGoHome() {
 }
 
 void setupDisplayAndFonts() {
-  if (gpio.getDeviceType() == HalGPIO::DeviceType::X3) {
-    display.setDisplayDimensions(792, 528);
-  }
   display.begin();
   renderer.begin();
   LOG_DBG("MAIN", "Display initialized");
@@ -305,8 +233,6 @@ void setupDisplayAndFonts() {
 }
 
 void setup() {
-  t1 = millis();
-
   gpio.begin();
 
   // Only start serial if USB connected
@@ -337,15 +263,9 @@ void setup() {
   const auto wakeupReason = gpio.getWakeupReason();
   switch (wakeupReason) {
     case HalGPIO::WakeupReason::PowerButton:
-      if (gpio.getDeviceType() == HalGPIO::DeviceType::X3) {
+      LOG_DBG("MAIN", "Verifying power button press duration");
-        LOG_DBG("MAIN", "Verifying power button press duration (X3)");
+      gpio.verifyPowerButtonWakeup(SETTINGS.getPowerButtonDuration(),
-        if (!verifyPowerButtonDurationX3()) {
+                                   SETTINGS.shortPwrBtn == CrossPointSettings::SHORT_PWRBTN::SLEEP);
-          gpio.startDeepSleep();
-        }
-      } else {
-        LOG_DBG("MAIN", "Verifying power button press duration");
-        verifyPowerButtonDuration();
-      }
       break;
     case HalGPIO::WakeupReason::AfterUSBPower:
       // If USB power caused a cold boot, go back to sleep
@@ -363,10 +283,6 @@ void setup() {
   LOG_DBG("MAIN", "Starting CrossPoint version " CROSSPOINT_VERSION);
 
   setupDisplayAndFonts();
-  if (wakeupReason == HalGPIO::WakeupReason::PowerButton || wakeupReason == HalGPIO::WakeupReason::AfterFlash ||
-      wakeupReason == HalGPIO::WakeupReason::Other) {
-    display.requestResync();
-  }
 
   exitActivity();
   enterNewActivity(new BootActivity(renderer, mappedInputManager));