Initial support for the x3

lib/hal/HalDisplay.cpp

@@ -9,6 +9,16 @@ HalDisplay::~HalDisplay() {}
 
 void HalDisplay::begin() { einkDisplay.begin(); }
 
+void HalDisplay::setDcPin(int8_t pin) { einkDisplay.setDcPin(pin); }
+
+void HalDisplay::setBusyActiveHigh(bool activeHigh) { einkDisplay.setBusyActiveHigh(activeHigh); }
+
+void HalDisplay::setBwOnly(bool bwOnly) { einkDisplay.setBwOnly(bwOnly); }
+
+void HalDisplay::setControllerType(EInkDisplay::ControllerType type) { einkDisplay.setControllerType(type); }
+
+void HalDisplay::setDisplayDimensions(uint16_t width, uint16_t height) { einkDisplay.setDisplayDimensions(width, height); }
+
 void HalDisplay::clearScreen(uint8_t color) const { einkDisplay.clearScreen(color); }
 
 void HalDisplay::drawImage(const uint8_t* imageData, uint16_t x, uint16_t y, uint16_t w, uint16_t h,
@@ -51,3 +61,11 @@ void HalDisplay::copyGrayscaleMsbBuffers(const uint8_t* msbBuffer) { einkDisplay
 void HalDisplay::cleanupGrayscaleBuffers(const uint8_t* bwBuffer) { einkDisplay.cleanupGrayscaleBuffers(bwBuffer); }
 
 void HalDisplay::displayGrayBuffer(bool turnOffScreen) { einkDisplay.displayGrayBuffer(turnOffScreen); }
+
+uint16_t HalDisplay::getDisplayWidth() const { return einkDisplay.getDisplayWidth(); }
+
+uint16_t HalDisplay::getDisplayHeight() const { return einkDisplay.getDisplayHeight(); }
+
+uint16_t HalDisplay::getDisplayWidthBytes() const { return einkDisplay.getDisplayWidthBytes(); }
+
+uint32_t HalDisplay::getBufferSize() const { return einkDisplay.getBufferSize(); }

lib/hal/HalDisplay.h

@@ -20,6 +20,13 @@ class HalDisplay {
   // Initialize the display hardware and driver
   void begin();
 
+  // Pre-begin display config passthroughs (used by X3 setup path)
+  void setDcPin(int8_t pin);
+  void setBusyActiveHigh(bool activeHigh);
+  void setBwOnly(bool bwOnly);
+  void setControllerType(EInkDisplay::ControllerType type);
+  void setDisplayDimensions(uint16_t width, uint16_t height);
+
   // Display dimensions
   static constexpr uint16_t DISPLAY_WIDTH = EInkDisplay::DISPLAY_WIDTH;
   static constexpr uint16_t DISPLAY_HEIGHT = EInkDisplay::DISPLAY_HEIGHT;
@@ -47,6 +54,12 @@ class HalDisplay {
 
   void displayGrayBuffer(bool turnOffScreen = false);
 
+  // Runtime geometry passthrough
+  uint16_t getDisplayWidth() const;
+  uint16_t getDisplayHeight() const;
+  uint16_t getDisplayWidthBytes() const;
+  uint32_t getBufferSize() const;
+
  private:
   EInkDisplay einkDisplay;
 };

lib/hal/HalGPIO.cpp

@@ -5,7 +5,14 @@
 void HalGPIO::begin() {
   inputMgr.begin();
   SPI.begin(EPD_SCLK, SPI_MISO, EPD_MOSI, EPD_CS);
-  pinMode(BAT_GPIO0, INPUT);
+
+  // X3 boards bias GPIO4 (EPD DC) around ~700 ADC counts at boot in our setup.
+  // X4 boards do not, and use GPIO0 for battery ADC.
+  _detectAdcValue = analogRead(4);
+  _deviceType = (_detectAdcValue > 500 && _detectAdcValue < 1200) ? DeviceType::X3 : DeviceType::X4;
+  _batteryPin = (_deviceType == DeviceType::X3) ? 4 : BAT_GPIO0;
+
+  pinMode(_batteryPin, INPUT);
   pinMode(UART0_RXD, INPUT);
 }
 
@@ -36,6 +43,10 @@ void HalGPIO::startDeepSleep() {
 }
 
 int HalGPIO::getBatteryPercentage() const {
+  if (_deviceType == DeviceType::X3) {
+    // X3 battery telemetry is not on ADC in stock fw; avoid fighting EPD DC on GPIO4.
+    return 0;
+  }
   static const BatteryMonitor battery = BatteryMonitor(BAT_GPIO0);
   return battery.readPercentage();
 }
@@ -61,4 +72,4 @@ HalGPIO::WakeupReason HalGPIO::getWakeupReason() const {
     return WakeupReason::AfterUSBPower;
   }
   return WakeupReason::Other;
-}
+}

lib/hal/HalGPIO.h

@@ -23,6 +23,14 @@ class HalGPIO {
   InputManager inputMgr;
 #endif
 
+ public:
+  enum class DeviceType : uint8_t { X4, X3 };
+
+ private:
+  DeviceType _deviceType = DeviceType::X4;
+  int _detectAdcValue = 0;
+  int _batteryPin = BAT_GPIO0;
+
  public:
   HalGPIO() = default;
 
@@ -47,6 +55,11 @@ class HalGPIO {
   // Check if USB is connected
   bool isUsbConnected() const;
 
+  // Device detection helpers
+  DeviceType getDeviceType() const { return _deviceType; }
+  int getDetectAdcValue() const { return _detectAdcValue; }
+  int getBatteryPin() const { return _batteryPin; }
+
   enum class WakeupReason { PowerButton, AfterFlash, AfterUSBPower, Other };
 
   WakeupReason getWakeupReason() const;