Fixes maintainer requests

.gitignore

@@ -9,4 +9,4 @@ build
 **/__pycache__/
 /compile_commands.json
 /.cache
-notes.md
+/notes.md

lib/hal/HalGPIO.cpp

@@ -1,5 +1,6 @@
 #include <HalGPIO.h>
 #include <SPI.h>
+#include <Wire.h>
 #include <esp_sleep.h>
 
 void HalGPIO::begin() {
@@ -14,6 +15,16 @@ void HalGPIO::begin() {
 
   pinMode(_batteryPin, INPUT);
   pinMode(UART0_RXD, INPUT);
+
+  // I2C init must come AFTER pinMode(UART0_RXD) because GPIO20 is shared
+  // between USB detection (digital read) and I2C SDA. Wire.begin()
+  // reconfigures the pin for I2C, so it must run last.
+  if (_deviceType == DeviceType::X3) {
+    Wire.begin(20, 0, 400000);
+    _useI2C = true;
+    _i2cAddr = 0x55;
+    _socRegister = 0x2C;
+  }
 }
 
 void HalGPIO::update() { inputMgr.update(); }
@@ -43,8 +54,18 @@ void HalGPIO::startDeepSleep() {
 }
 
 int HalGPIO::getBatteryPercentage() const {
-  if (_deviceType == DeviceType::X3) {
+  if (_useI2C) {
-    return 0;
+    // 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.write(_socRegister);
+    if (Wire.endTransmission(false) != 0) return 0;
+    Wire.requestFrom(_i2cAddr, (uint8_t)2);
+    if (Wire.available() < 2) return 0;
+    const uint8_t lo = Wire.read();
+    const uint8_t hi = Wire.read();
+    const uint16_t soc = (hi << 8) | lo;
+    return soc > 100 ? 100 : soc;
   }
   static const BatteryMonitor bat(BAT_GPIO0);
   return bat.readPercentage();

lib/hal/HalGPIO.h

@@ -30,6 +30,9 @@ class HalGPIO {
   DeviceType _deviceType = DeviceType::X4;
   int _detectAdcValue = 0;
   int _batteryPin = BAT_GPIO0;
+  bool _useI2C = false;
+  uint8_t _i2cAddr = 0;
+  uint8_t _socRegister = 0;
 
  public:
   HalGPIO() = default;
@@ -73,3 +76,5 @@ class HalGPIO {
   static constexpr uint8_t BTN_DOWN = 5;
   static constexpr uint8_t BTN_POWER = 6;
 };
+
+extern HalGPIO gpio;

platformio.ini

@@ -41,10 +41,12 @@ extra_scripts =
 
 ; Libraries
 lib_deps =
-  BatteryMonitor=symlink://open-x4-sdk/libs/hardware/BatteryMonitor
+  ; Use standalone community-sdk checkout (sibling folder) instead of submodule.
-  InputManager=symlink://open-x4-sdk/libs/hardware/InputManager
+  ; This makes local SDK edits in ../community-sdk immediately used by crosspoint-reader.
-  EInkDisplay=symlink://open-x4-sdk/libs/display/EInkDisplay
+  BatteryMonitor=symlink://../community-sdk/libs/hardware/BatteryMonitor
-  SDCardManager=symlink://open-x4-sdk/libs/hardware/SDCardManager
+  InputManager=symlink://../community-sdk/libs/hardware/InputManager
+  EInkDisplay=symlink://../community-sdk/libs/display/EInkDisplay
+  SDCardManager=symlink://../community-sdk/libs/hardware/SDCardManager
   bblanchon/ArduinoJson @ 7.4.2
   ricmoo/QRCode @ 0.0.1
   links2004/WebSockets @ 2.7.3

src/Battery.cpp

@@ -1,33 +0,0 @@
-#include "Battery.h"
-#include <Wire.h>
-
-void BatteryProvider::setI2CFuelGauge(uint8_t i2cAddr, uint8_t socRegister) {
-  _useI2C = true;
-  _i2cAddr = i2cAddr;
-  _socRegister = socRegister;
-}
-
-uint16_t BatteryProvider::readPercentage() const {
-  if (_useI2C) {
-    // 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.write(_socRegister);
-    if (Wire.endTransmission(false) != 0) return 0;
-    Wire.requestFrom(_i2cAddr, (uint8_t)2);
-    if (Wire.available() < 2) return 0;
-    const uint8_t lo = Wire.read();
-    const uint8_t hi = Wire.read();
-    const uint16_t soc = (hi << 8) | lo;
-    return soc > 100 ? 100 : soc;
-  }
-  // ADC path: read raw voltage, apply divider, convert via LiPo polynomial
-  return _adcMonitor.readPercentage();
-}
-
-// Meyer's singleton — single shared instance across all translation units.
-// Defaults to X4 ADC mode. For X3, main.cpp calls setI2CFuelGauge() to switch.
-BatteryProvider& battery() {
-  static BatteryProvider instance;
-  return instance;
-}

src/Battery.h

@@ -1,29 +0,0 @@
-#pragma once
-#include <BatteryMonitor.h>
-#include <cstdint>
-
-#define BAT_GPIO0 0  // Battery voltage (X4 ADC pin)
-
-// Unified battery reader supporting two backends:
-//   - X4: ADC voltage divider on GPIO0 (default, no setup needed)
-//   - X3: BQ27220 fuel gauge via I2C at 0x55, SOC register 0x2C
-//         (call setI2CFuelGauge() after Wire.begin())
-class BatteryProvider {
- public:
-  // Read battery percentage (0-100). Delegates to ADC or I2C depending on mode.
-  uint16_t readPercentage() const;
-
-  // Switch to I2C fuel gauge mode. Wire.begin() must be called first.
-  // i2cAddr: fuel gauge I2C address (e.g. 0x55 for BQ27220)
-  // socRegister: register holding state-of-charge 0-100% (e.g. 0x2C)
-  void setI2CFuelGauge(uint8_t i2cAddr, uint8_t socRegister);
-
- private:
-  BatteryMonitor _adcMonitor{BAT_GPIO0};
-  bool _useI2C = false;
-  uint8_t _i2cAddr = 0;
-  uint8_t _socRegister = 0;
-};
-
-// Shared singleton used by themes and activities.
-BatteryProvider& battery();

src/activities/home/HomeActivity.cpp

@@ -10,7 +10,6 @@
 #include <cstring>
 #include <vector>
 
-#include "Battery.h"
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "MappedInputManager.h"

src/activities/reader/EpubReaderActivity.cpp

@@ -3,6 +3,7 @@
 #include <Epub/Page.h>
 #include <FsHelpers.h>
 #include <GfxRenderer.h>
+#include <HalGPIO.h>
 #include <HalStorage.h>
 #include <Logging.h>
 
@@ -34,12 +35,6 @@ int clampPercent(int percent) {
   return percent;
 }
 
-bool isX3DisplayGeometry(const GfxRenderer& renderer) {
-  const int w = renderer.getScreenWidth();
-  const int h = renderer.getScreenHeight();
-  return (w == 792 && h == 528) || (w == 528 && h == 792);
-}
-
 // Apply the logical reader orientation to the renderer.
 // This centralizes orientation mapping so we don't duplicate switch logic elsewhere.
 void applyReaderOrientation(GfxRenderer& renderer, const uint8_t orientation) {
@@ -688,7 +683,7 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
     pagesUntilFullRefresh--;
   }
 
-  const bool useGrayscaleAA = SETTINGS.textAntiAliasing && !isX3DisplayGeometry(renderer);
+  const bool useGrayscaleAA = SETTINGS.textAntiAliasing && gpio.getDeviceType() != HalGPIO::DeviceType::X3;
   if (useGrayscaleAA) {
     // Save BW buffer only when we actually run grayscale passes.
     renderer.storeBwBuffer();

src/components/themes/BaseTheme.cpp

@@ -8,7 +8,7 @@
 #include <cstdint>
 #include <string>
 
-#include "Battery.h"
+#include <HalGPIO.h>
 #include "RecentBooksStore.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
@@ -23,7 +23,7 @@ constexpr int homeMarginTop = 30;
 void BaseTheme::drawBattery(const GfxRenderer& renderer, Rect rect, const bool showPercentage) const {
   // Left aligned battery icon and percentage
   // TODO refactor this so the percentage doesnt change after we position it
-  const uint16_t percentage = battery().readPercentage();
+  const uint16_t percentage = gpio.getBatteryPercentage();
   if (showPercentage) {
     const auto percentageText = std::to_string(percentage) + "%";
     renderer.drawText(SMALL_FONT_ID, rect.x + batteryPercentSpacing + BaseMetrics::values.batteryWidth, rect.y,
@@ -233,7 +233,7 @@ void BaseTheme::drawHeader(const GfxRenderer& renderer, Rect rect, const char* t
       SETTINGS.hideBatteryPercentage != CrossPointSettings::HIDE_BATTERY_PERCENTAGE::HIDE_ALWAYS;
   int batteryX = rect.x + rect.width - BaseMetrics::values.contentSidePadding - BaseMetrics::values.batteryWidth;
   if (showBatteryPercentage) {
-    const uint16_t percentage = battery().readPercentage();
+    const uint16_t percentage = gpio.getBatteryPercentage();
     const auto percentageText = std::to_string(percentage) + "%";
     batteryX -= renderer.getTextWidth(SMALL_FONT_ID, percentageText.c_str());
   }

src/components/themes/lyra/LyraTheme.cpp

@@ -6,7 +6,7 @@
 #include <cstdint>
 #include <string>
 
-#include "Battery.h"
+#include <HalGPIO.h>
 #include "RecentBooksStore.h"
 #include "components/UITheme.h"
 #include "fontIds.h"
@@ -22,7 +22,7 @@ constexpr int topHintButtonY = 345;
 
 void LyraTheme::drawBattery(const GfxRenderer& renderer, Rect rect, const bool showPercentage) const {
   // Left aligned battery icon and percentage
-  const uint16_t percentage = battery().readPercentage();
+  const uint16_t percentage = gpio.getBatteryPercentage();
   if (showPercentage) {
     const auto percentageText = std::to_string(percentage) + "%";
     renderer.drawText(SMALL_FONT_ID, rect.x + batteryPercentSpacing + LyraMetrics::values.batteryWidth, rect.y,
@@ -64,7 +64,7 @@ void LyraTheme::drawHeader(const GfxRenderer& renderer, Rect rect, const char* t
       SETTINGS.hideBatteryPercentage != CrossPointSettings::HIDE_BATTERY_PERCENTAGE::HIDE_ALWAYS;
   int batteryX = rect.x + rect.width - LyraMetrics::values.contentSidePadding - LyraMetrics::values.batteryWidth;
   if (showBatteryPercentage) {
-    const uint16_t percentage = battery().readPercentage();
+    const uint16_t percentage = gpio.getBatteryPercentage();
     const auto percentageText = std::to_string(percentage) + "%";
     batteryX -= renderer.getTextWidth(SMALL_FONT_ID, percentageText.c_str());
   }

src/main.cpp

@@ -6,12 +6,9 @@
 #include <HalStorage.h>
 #include <Logging.h>
 #include <SPI.h>
-#include <Wire.h>
 #include <builtinFonts/all.h>
 
 #include <cstring>
-
-#include "Battery.h"
 #include "CrossPointSettings.h"
 #include "CrossPointState.h"
 #include "KOReaderCredentialStore.h"
@@ -130,12 +127,6 @@ EpdFontFamily ui12FontFamily(&ui12RegularFont, &ui12BoldFont);
 unsigned long t1 = 0;
 unsigned long t2 = 0;
 
-inline void requestResyncIfX3(uint8_t settlePasses = 0) {
-  if (gpio.getDeviceType() == HalGPIO::DeviceType::X3) {
-    display.requestResync(settlePasses);
-  }
-}
-
 void exitActivity() {
   if (currentActivity) {
     currentActivity->onExit();
@@ -243,7 +234,7 @@ void enterDeepSleep() {
   APP_STATE.lastSleepFromReader = currentActivity && currentActivity->isReaderActivity();
   APP_STATE.saveToFile();
   exitActivity();
-  requestResyncIfX3(0);
+  display.requestResync();
   enterNewActivity(new SleepActivity(renderer, mappedInputManager));
 
   display.deepSleep();
@@ -294,9 +285,7 @@ void onGoToBrowser() {
 
 void onGoHome() {
   const bool returningFromReader = currentActivity && currentActivity->isReaderActivity();
-  if (returningFromReader && (gpio.getDeviceType() == HalGPIO::DeviceType::X3)) {
+  if (returningFromReader) {
-    // Force Home's first frame to run a full resync on X3.
-    // Avoid doing a blocking scrub refresh before activity transition.
     display.requestResync(1);
   }
   exitActivity();
@@ -307,11 +296,6 @@ void onGoHome() {
 void setupDisplayAndFonts() {
   if (gpio.getDeviceType() == HalGPIO::DeviceType::X3) {
     display.setDisplayDimensions(792, 528);
-    // X3 has a BQ27220 fuel gauge on I2C (addr 0x55) instead of an ADC voltage
-    // divider. SOC (0-100%) is read directly from register 0x2C.
-    // I2C bus: SDA=GPIO20, SCL=GPIO0, 400kHz (matches stock X3 firmware).
-    Wire.begin(20, 0, 400000);
-    battery().setI2CFuelGauge(0x55, 0x2C);
   }
   display.begin();
   renderer.begin();
@@ -401,7 +385,7 @@ void setup() {
   setupDisplayAndFonts();
   if (wakeupReason == HalGPIO::WakeupReason::PowerButton || wakeupReason == HalGPIO::WakeupReason::AfterFlash ||
       wakeupReason == HalGPIO::WakeupReason::Other) {
-    requestResyncIfX3(0);
+    display.requestResync();
   }
 
   exitActivity();