Merge b5922b91b7 into da4d3b5ea5

## Summary

Extracted some changes from
https://github.com/crosspoint-reader/crosspoint-reader/pull/500 to make
reviewing easier

This PR adds HAL (Hardware Abstraction Layer) for display and GPIO
components, making it easier to write a stub or an emulated
implementation of the hardware.

SD card HAL will be added via another PR, because it's a bit more
tricky.

---

### AI Usage

While CrossPoint doesn't have restrictions on AI tools in contributing,
please be transparent about their usage as it
helps set the right context for reviewers.

Did you use AI tools to help write this code? **NO**

.gitignore

@@ -6,4 +6,6 @@ lib/EpdFont/fontsrc
 *.generated.h
 .vs
 build
-**/__pycache__/
+**/__pycache__/
+/compile_commands.json
+/.cache

lib/Epub/Epub/parsers/ChapterHtmlSlimParser.cpp

@@ -84,41 +84,42 @@ void XMLCALL ChapterHtmlSlimParser::startElement(void* userData, const XML_Char*
   if (strcmp(name, "table") == 0) {
     // Add placeholder text
     self->startNewTextBlock(TextBlock::CENTER_ALIGN);
-    if (self->currentTextBlock) {
-      self->currentTextBlock->addWord("[Table omitted]", EpdFontFamily::ITALIC);
-    }
 
-    // Skip table contents
-    self->skipUntilDepth = self->depth;
+    self->italicUntilDepth = min(self->italicUntilDepth, self->depth);
+    // Advance depth before processing character data (like you would for a element with text)
     self->depth += 1;
+    self->characterData(userData, "[Table omitted]", strlen("[Table omitted]"));
+
+    // Skip table contents (skip until parent as we pre-advanced depth above)
+    self->skipUntilDepth = self->depth - 1;
     return;
   }
 
   if (matches(name, IMAGE_TAGS, NUM_IMAGE_TAGS)) {
     // TODO: Start processing image tags
-    std::string alt;
+    std::string alt = "[Image]";
     if (atts != nullptr) {
       for (int i = 0; atts[i]; i += 2) {
         if (strcmp(atts[i], "alt") == 0) {
-          // add " " (counts as whitespace) at the end of alt
-          //  so the corresponding text block ends.
-          // TODO: A zero-width breaking space would be more appropriate (once/if we support it)
-          alt = "[Image: " + std::string(atts[i + 1]) + "] ";
+          if (strlen(atts[i + 1]) > 0) {
+            alt = "[Image: " + std::string(atts[i + 1]) + "]";
+          }
+          break;
         }
       }
-      Serial.printf("[%lu] [EHP] Image alt: %s\n", millis(), alt.c_str());
-
-      self->startNewTextBlock(TextBlock::CENTER_ALIGN);
-      self->italicUntilDepth = min(self->italicUntilDepth, self->depth);
-      self->depth += 1;
-      self->characterData(userData, alt.c_str(), alt.length());
-      return;
-    } else {
-      // Skip for now
-      self->skipUntilDepth = self->depth;
-      self->depth += 1;
-      return;
     }
+
+    Serial.printf("[%lu] [EHP] Image alt: %s\n", millis(), alt.c_str());
+
+    self->startNewTextBlock(TextBlock::CENTER_ALIGN);
+    self->italicUntilDepth = min(self->italicUntilDepth, self->depth);
+    // Advance depth before processing character data (like you would for a element with text)
+    self->depth += 1;
+    self->characterData(userData, alt.c_str(), alt.length());
+
+    // Skip table contents (skip until parent as we pre-advanced depth above)
+    self->skipUntilDepth = self->depth - 1;
+    return;
   }
 
   if (matches(name, SKIP_TAGS, NUM_SKIP_TAGS)) {
@@ -143,25 +144,43 @@ void XMLCALL ChapterHtmlSlimParser::startElement(void* userData, const XML_Char*
   if (matches(name, HEADER_TAGS, NUM_HEADER_TAGS)) {
     self->startNewTextBlock(TextBlock::CENTER_ALIGN);
     self->boldUntilDepth = std::min(self->boldUntilDepth, self->depth);
-  } else if (matches(name, BLOCK_TAGS, NUM_BLOCK_TAGS)) {
+    self->depth += 1;
+    return;
+  }
+
+  if (matches(name, BLOCK_TAGS, NUM_BLOCK_TAGS)) {
     if (strcmp(name, "br") == 0) {
       if (self->partWordBufferIndex > 0) {
         // flush word preceding <br/> to currentTextBlock before calling startNewTextBlock
         self->flushPartWordBuffer();
       }
       self->startNewTextBlock(self->currentTextBlock->getStyle());
-    } else {
-      self->startNewTextBlock((TextBlock::Style)self->paragraphAlignment);
-      if (strcmp(name, "li") == 0) {
-        self->currentTextBlock->addWord("\xe2\x80\xa2", EpdFontFamily::REGULAR);
-      }
+      self->depth += 1;
+      return;
     }
-  } else if (matches(name, BOLD_TAGS, NUM_BOLD_TAGS)) {
-    self->boldUntilDepth = std::min(self->boldUntilDepth, self->depth);
-  } else if (matches(name, ITALIC_TAGS, NUM_ITALIC_TAGS)) {
-    self->italicUntilDepth = std::min(self->italicUntilDepth, self->depth);
+
+    self->startNewTextBlock(static_cast<TextBlock::Style>(self->paragraphAlignment));
+    if (strcmp(name, "li") == 0) {
+      self->currentTextBlock->addWord("\xe2\x80\xa2", EpdFontFamily::REGULAR);
+    }
+
+    self->depth += 1;
+    return;
   }
 
+  if (matches(name, BOLD_TAGS, NUM_BOLD_TAGS)) {
+    self->boldUntilDepth = std::min(self->boldUntilDepth, self->depth);
+    self->depth += 1;
+    return;
+  }
+
+  if (matches(name, ITALIC_TAGS, NUM_ITALIC_TAGS)) {
+    self->italicUntilDepth = std::min(self->italicUntilDepth, self->depth);
+    self->depth += 1;
+    return;
+  }
+
+  // Unprocessed tag, just increasing depth and continue forward
   self->depth += 1;
 }
 
@@ -227,7 +246,8 @@ void XMLCALL ChapterHtmlSlimParser::endElement(void* userData, const XML_Char* n
     // text styling needs to be overhauled to fix it.
     const bool shouldBreakText =
         matches(name, BLOCK_TAGS, NUM_BLOCK_TAGS) || matches(name, HEADER_TAGS, NUM_HEADER_TAGS) ||
-        matches(name, BOLD_TAGS, NUM_BOLD_TAGS) || matches(name, ITALIC_TAGS, NUM_ITALIC_TAGS) || self->depth == 1;
+        matches(name, BOLD_TAGS, NUM_BOLD_TAGS) || matches(name, ITALIC_TAGS, NUM_ITALIC_TAGS) ||
+        strcmp(name, "table") == 0 || matches(name, IMAGE_TAGS, NUM_IMAGE_TAGS) || self->depth == 1;
 
     if (shouldBreakText) {
       self->flushPartWordBuffer();

lib/GfxRenderer/GfxRenderer.cpp

@@ -10,19 +10,19 @@ void GfxRenderer::rotateCoordinates(const int x, const int y, int* rotatedX, int
       // Logical portrait (480x800) → panel (800x480)
       // Rotation: 90 degrees clockwise
       *rotatedX = y;
-      *rotatedY = EInkDisplay::DISPLAY_HEIGHT - 1 - x;
+      *rotatedY = HalDisplay::DISPLAY_HEIGHT - 1 - x;
       break;
     }
     case LandscapeClockwise: {
       // Logical landscape (800x480) rotated 180 degrees (swap top/bottom and left/right)
-      *rotatedX = EInkDisplay::DISPLAY_WIDTH - 1 - x;
-      *rotatedY = EInkDisplay::DISPLAY_HEIGHT - 1 - y;
+      *rotatedX = HalDisplay::DISPLAY_WIDTH - 1 - x;
+      *rotatedY = HalDisplay::DISPLAY_HEIGHT - 1 - y;
       break;
     }
     case PortraitInverted: {
       // Logical portrait (480x800) → panel (800x480)
       // Rotation: 90 degrees counter-clockwise
-      *rotatedX = EInkDisplay::DISPLAY_WIDTH - 1 - y;
+      *rotatedX = HalDisplay::DISPLAY_WIDTH - 1 - y;
       *rotatedY = x;
       break;
     }
@@ -36,7 +36,7 @@ void GfxRenderer::rotateCoordinates(const int x, const int y, int* rotatedX, int
 }
 
 void GfxRenderer::drawPixel(const int x, const int y, const bool state) const {
-  uint8_t* frameBuffer = einkDisplay.getFrameBuffer();
+  uint8_t* frameBuffer = display.getFrameBuffer();
 
   // Early return if no framebuffer is set
   if (!frameBuffer) {
@@ -49,14 +49,13 @@ void GfxRenderer::drawPixel(const int x, const int y, const bool state) const {
   rotateCoordinates(x, y, &rotatedX, &rotatedY);
 
   // Bounds checking against physical panel dimensions
-  if (rotatedX < 0 || rotatedX >= EInkDisplay::DISPLAY_WIDTH || rotatedY < 0 ||
-      rotatedY >= EInkDisplay::DISPLAY_HEIGHT) {
+  if (rotatedX < 0 || rotatedX >= HalDisplay::DISPLAY_WIDTH || rotatedY < 0 || rotatedY >= HalDisplay::DISPLAY_HEIGHT) {
     Serial.printf("[%lu] [GFX] !! Outside range (%d, %d) -> (%d, %d)\n", millis(), x, y, rotatedX, rotatedY);
     return;
   }
 
   // Calculate byte position and bit position
-  const uint16_t byteIndex = rotatedY * EInkDisplay::DISPLAY_WIDTH_BYTES + (rotatedX / 8);
+  const uint16_t byteIndex = rotatedY * HalDisplay::DISPLAY_WIDTH_BYTES + (rotatedX / 8);
   const uint8_t bitPosition = 7 - (rotatedX % 8);  // MSB first
 
   if (state) {
@@ -164,7 +163,7 @@ void GfxRenderer::drawImage(const uint8_t bitmap[], const int x, const int y, co
       break;
   }
   // TODO: Rotate bits
-  einkDisplay.drawImage(bitmap, rotatedX, rotatedY, width, height);
+  display.drawImage(bitmap, rotatedX, rotatedY, width, height);
 }
 
 void GfxRenderer::drawBitmap(const Bitmap& bitmap, const int x, const int y, const int maxWidth, const int maxHeight,
@@ -399,22 +398,20 @@ void GfxRenderer::fillPolygon(const int* xPoints, const int* yPoints, int numPoi
   free(nodeX);
 }
 
-void GfxRenderer::clearScreen(const uint8_t color) const { einkDisplay.clearScreen(color); }
+void GfxRenderer::clearScreen(const uint8_t color) const { display.clearScreen(color); }
 
 void GfxRenderer::invertScreen() const {
-  uint8_t* buffer = einkDisplay.getFrameBuffer();
+  uint8_t* buffer = display.getFrameBuffer();
   if (!buffer) {
     Serial.printf("[%lu] [GFX] !! No framebuffer in invertScreen\n", millis());
     return;
   }
-  for (int i = 0; i < EInkDisplay::BUFFER_SIZE; i++) {
+  for (int i = 0; i < HalDisplay::BUFFER_SIZE; i++) {
     buffer[i] = ~buffer[i];
   }
 }
 
-void GfxRenderer::displayBuffer(const EInkDisplay::RefreshMode refreshMode) const {
-  einkDisplay.displayBuffer(refreshMode);
-}
+void GfxRenderer::displayBuffer(const HalDisplay::RefreshMode refreshMode) const { display.displayBuffer(refreshMode); }
 
 std::string GfxRenderer::truncatedText(const int fontId, const char* text, const int maxWidth,
                                        const EpdFontFamily::Style style) const {
@@ -433,13 +430,13 @@ int GfxRenderer::getScreenWidth() const {
     case Portrait:
     case PortraitInverted:
       // 480px wide in portrait logical coordinates
-      return EInkDisplay::DISPLAY_HEIGHT;
+      return HalDisplay::DISPLAY_HEIGHT;
     case LandscapeClockwise:
     case LandscapeCounterClockwise:
       // 800px wide in landscape logical coordinates
-      return EInkDisplay::DISPLAY_WIDTH;
+      return HalDisplay::DISPLAY_WIDTH;
   }
-  return EInkDisplay::DISPLAY_HEIGHT;
+  return HalDisplay::DISPLAY_HEIGHT;
 }
 
 int GfxRenderer::getScreenHeight() const {
@@ -447,13 +444,13 @@ int GfxRenderer::getScreenHeight() const {
     case Portrait:
     case PortraitInverted:
       // 800px tall in portrait logical coordinates
-      return EInkDisplay::DISPLAY_WIDTH;
+      return HalDisplay::DISPLAY_WIDTH;
     case LandscapeClockwise:
     case LandscapeCounterClockwise:
       // 480px tall in landscape logical coordinates
-      return EInkDisplay::DISPLAY_HEIGHT;
+      return HalDisplay::DISPLAY_HEIGHT;
   }
-  return EInkDisplay::DISPLAY_WIDTH;
+  return HalDisplay::DISPLAY_WIDTH;
 }
 
 int GfxRenderer::getSpaceWidth(const int fontId) const {
@@ -653,17 +650,18 @@ void GfxRenderer::drawTextRotated90CW(const int fontId, const int x, const int y
   }
 }
 
-uint8_t* GfxRenderer::getFrameBuffer() const { return einkDisplay.getFrameBuffer(); }
+uint8_t* GfxRenderer::getFrameBuffer() const { return display.getFrameBuffer(); }
 
-size_t GfxRenderer::getBufferSize() { return EInkDisplay::BUFFER_SIZE; }
+size_t GfxRenderer::getBufferSize() { return HalDisplay::BUFFER_SIZE; }
 
-void GfxRenderer::grayscaleRevert() const { einkDisplay.grayscaleRevert(); }
+// unused
+// void GfxRenderer::grayscaleRevert() const { display.grayscaleRevert(); }
 
-void GfxRenderer::copyGrayscaleLsbBuffers() const { einkDisplay.copyGrayscaleLsbBuffers(einkDisplay.getFrameBuffer()); }
+void GfxRenderer::copyGrayscaleLsbBuffers() const { display.copyGrayscaleLsbBuffers(display.getFrameBuffer()); }
 
-void GfxRenderer::copyGrayscaleMsbBuffers() const { einkDisplay.copyGrayscaleMsbBuffers(einkDisplay.getFrameBuffer()); }
+void GfxRenderer::copyGrayscaleMsbBuffers() const { display.copyGrayscaleMsbBuffers(display.getFrameBuffer()); }
 
-void GfxRenderer::displayGrayBuffer() const { einkDisplay.displayGrayBuffer(); }
+void GfxRenderer::displayGrayBuffer() const { display.displayGrayBuffer(); }
 
 void GfxRenderer::freeBwBufferChunks() {
   for (auto& bwBufferChunk : bwBufferChunks) {
@@ -681,7 +679,7 @@ void GfxRenderer::freeBwBufferChunks() {
  * Returns true if buffer was stored successfully, false if allocation failed.
  */
 bool GfxRenderer::storeBwBuffer() {
-  const uint8_t* frameBuffer = einkDisplay.getFrameBuffer();
+  const uint8_t* frameBuffer = display.getFrameBuffer();
   if (!frameBuffer) {
     Serial.printf("[%lu] [GFX] !! No framebuffer in storeBwBuffer\n", millis());
     return false;
@@ -736,7 +734,7 @@ void GfxRenderer::restoreBwBuffer() {
     return;
   }
 
-  uint8_t* frameBuffer = einkDisplay.getFrameBuffer();
+  uint8_t* frameBuffer = display.getFrameBuffer();
   if (!frameBuffer) {
     Serial.printf("[%lu] [GFX] !! No framebuffer in restoreBwBuffer\n", millis());
     freeBwBufferChunks();
@@ -755,7 +753,7 @@ void GfxRenderer::restoreBwBuffer() {
     memcpy(frameBuffer + offset, bwBufferChunks[i], BW_BUFFER_CHUNK_SIZE);
   }
 
-  einkDisplay.cleanupGrayscaleBuffers(frameBuffer);
+  display.cleanupGrayscaleBuffers(frameBuffer);
 
   freeBwBufferChunks();
   Serial.printf("[%lu] [GFX] Restored and freed BW buffer chunks\n", millis());
@@ -766,9 +764,9 @@ void GfxRenderer::restoreBwBuffer() {
  * Use this when BW buffer was re-rendered instead of stored/restored.
  */
 void GfxRenderer::cleanupGrayscaleWithFrameBuffer() const {
-  uint8_t* frameBuffer = einkDisplay.getFrameBuffer();
+  uint8_t* frameBuffer = display.getFrameBuffer();
   if (frameBuffer) {
-    einkDisplay.cleanupGrayscaleBuffers(frameBuffer);
+    display.cleanupGrayscaleBuffers(frameBuffer);
   }
 }
 

lib/GfxRenderer/GfxRenderer.h

@@ -1,7 +1,7 @@
 #pragma once
 
-#include <EInkDisplay.h>
 #include <EpdFontFamily.h>
+#include <HalDisplay.h>
 
 #include <map>
 
@@ -21,11 +21,11 @@ class GfxRenderer {
 
  private:
   static constexpr size_t BW_BUFFER_CHUNK_SIZE = 8000;  // 8KB chunks to allow for non-contiguous memory
-  static constexpr size_t BW_BUFFER_NUM_CHUNKS = EInkDisplay::BUFFER_SIZE / BW_BUFFER_CHUNK_SIZE;
-  static_assert(BW_BUFFER_CHUNK_SIZE * BW_BUFFER_NUM_CHUNKS == EInkDisplay::BUFFER_SIZE,
+  static constexpr size_t BW_BUFFER_NUM_CHUNKS = HalDisplay::BUFFER_SIZE / BW_BUFFER_CHUNK_SIZE;
+  static_assert(BW_BUFFER_CHUNK_SIZE * BW_BUFFER_NUM_CHUNKS == HalDisplay::BUFFER_SIZE,
                 "BW buffer chunking does not line up with display buffer size");
 
-  EInkDisplay& einkDisplay;
+  HalDisplay& display;
   RenderMode renderMode;
   Orientation orientation;
   uint8_t* bwBufferChunks[BW_BUFFER_NUM_CHUNKS] = {nullptr};
@@ -36,7 +36,7 @@ class GfxRenderer {
   void rotateCoordinates(int x, int y, int* rotatedX, int* rotatedY) const;
 
  public:
-  explicit GfxRenderer(EInkDisplay& einkDisplay) : einkDisplay(einkDisplay), renderMode(BW), orientation(Portrait) {}
+  explicit GfxRenderer(HalDisplay& halDisplay) : display(halDisplay), renderMode(BW), orientation(Portrait) {}
   ~GfxRenderer() { freeBwBufferChunks(); }
 
   static constexpr int VIEWABLE_MARGIN_TOP = 9;
@@ -54,7 +54,7 @@ class GfxRenderer {
   // Screen ops
   int getScreenWidth() const;
   int getScreenHeight() const;
-  void displayBuffer(EInkDisplay::RefreshMode refreshMode = EInkDisplay::FAST_REFRESH) const;
+  void displayBuffer(HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH) const;
   // EXPERIMENTAL: Windowed update - display only a rectangular region
   void displayWindow(int x, int y, int width, int height) const;
   void invertScreen() const;

lib/hal/HalDisplay.cpp

@@ -0,0 +1,51 @@
+#include <HalDisplay.h>
+#include <HalGPIO.h>
+
+#define SD_SPI_MISO 7
+
+HalDisplay::HalDisplay() : einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY) {}
+
+HalDisplay::~HalDisplay() {}
+
+void HalDisplay::begin() { einkDisplay.begin(); }
+
+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,
+                           bool fromProgmem) const {
+  einkDisplay.drawImage(imageData, x, y, w, h, fromProgmem);
+}
+
+EInkDisplay::RefreshMode convertRefreshMode(HalDisplay::RefreshMode mode) {
+  switch (mode) {
+    case HalDisplay::FULL_REFRESH:
+      return EInkDisplay::FULL_REFRESH;
+    case HalDisplay::HALF_REFRESH:
+      return EInkDisplay::HALF_REFRESH;
+    case HalDisplay::FAST_REFRESH:
+    default:
+      return EInkDisplay::FAST_REFRESH;
+  }
+}
+
+void HalDisplay::displayBuffer(HalDisplay::RefreshMode mode) { einkDisplay.displayBuffer(convertRefreshMode(mode)); }
+
+void HalDisplay::refreshDisplay(HalDisplay::RefreshMode mode, bool turnOffScreen) {
+  einkDisplay.refreshDisplay(convertRefreshMode(mode), turnOffScreen);
+}
+
+void HalDisplay::deepSleep() { einkDisplay.deepSleep(); }
+
+uint8_t* HalDisplay::getFrameBuffer() const { return einkDisplay.getFrameBuffer(); }
+
+void HalDisplay::copyGrayscaleBuffers(const uint8_t* lsbBuffer, const uint8_t* msbBuffer) {
+  einkDisplay.copyGrayscaleBuffers(lsbBuffer, msbBuffer);
+}
+
+void HalDisplay::copyGrayscaleLsbBuffers(const uint8_t* lsbBuffer) { einkDisplay.copyGrayscaleLsbBuffers(lsbBuffer); }
+
+void HalDisplay::copyGrayscaleMsbBuffers(const uint8_t* msbBuffer) { einkDisplay.copyGrayscaleMsbBuffers(msbBuffer); }
+
+void HalDisplay::cleanupGrayscaleBuffers(const uint8_t* bwBuffer) { einkDisplay.cleanupGrayscaleBuffers(bwBuffer); }
+
+void HalDisplay::displayGrayBuffer() { einkDisplay.displayGrayBuffer(); }

lib/hal/HalDisplay.h

@@ -0,0 +1,52 @@
+#pragma once
+#include <Arduino.h>
+#include <EInkDisplay.h>
+
+class HalDisplay {
+ public:
+  // Constructor with pin configuration
+  HalDisplay();
+
+  // Destructor
+  ~HalDisplay();
+
+  // Refresh modes
+  enum RefreshMode {
+    FULL_REFRESH,  // Full refresh with complete waveform
+    HALF_REFRESH,  // Half refresh (1720ms) - balanced quality and speed
+    FAST_REFRESH   // Fast refresh using custom LUT
+  };
+
+  // Initialize the display hardware and driver
+  void begin();
+
+  // Display dimensions
+  static constexpr uint16_t DISPLAY_WIDTH = EInkDisplay::DISPLAY_WIDTH;
+  static constexpr uint16_t DISPLAY_HEIGHT = EInkDisplay::DISPLAY_HEIGHT;
+  static constexpr uint16_t DISPLAY_WIDTH_BYTES = DISPLAY_WIDTH / 8;
+  static constexpr uint32_t BUFFER_SIZE = DISPLAY_WIDTH_BYTES * DISPLAY_HEIGHT;
+
+  // Frame buffer operations
+  void clearScreen(uint8_t color = 0xFF) const;
+  void drawImage(const uint8_t* imageData, uint16_t x, uint16_t y, uint16_t w, uint16_t h,
+                 bool fromProgmem = false) const;
+
+  void displayBuffer(RefreshMode mode = RefreshMode::FAST_REFRESH);
+  void refreshDisplay(RefreshMode mode = RefreshMode::FAST_REFRESH, bool turnOffScreen = false);
+
+  // Power management
+  void deepSleep();
+
+  // Access to frame buffer
+  uint8_t* getFrameBuffer() const;
+
+  void copyGrayscaleBuffers(const uint8_t* lsbBuffer, const uint8_t* msbBuffer);
+  void copyGrayscaleLsbBuffers(const uint8_t* lsbBuffer);
+  void copyGrayscaleMsbBuffers(const uint8_t* msbBuffer);
+  void cleanupGrayscaleBuffers(const uint8_t* bwBuffer);
+
+  void displayGrayBuffer();
+
+ private:
+  EInkDisplay einkDisplay;
+};

lib/hal/HalGPIO.cpp

@@ -0,0 +1,55 @@
+#include <HalGPIO.h>
+#include <SPI.h>
+#include <esp_sleep.h>
+
+void HalGPIO::begin() {
+  inputMgr.begin();
+  SPI.begin(EPD_SCLK, SPI_MISO, EPD_MOSI, EPD_CS);
+  pinMode(BAT_GPIO0, INPUT);
+  pinMode(UART0_RXD, INPUT);
+}
+
+void HalGPIO::update() { inputMgr.update(); }
+
+bool HalGPIO::isPressed(uint8_t buttonIndex) const { return inputMgr.isPressed(buttonIndex); }
+
+bool HalGPIO::wasPressed(uint8_t buttonIndex) const { return inputMgr.wasPressed(buttonIndex); }
+
+bool HalGPIO::wasAnyPressed() const { return inputMgr.wasAnyPressed(); }
+
+bool HalGPIO::wasReleased(uint8_t buttonIndex) const { return inputMgr.wasReleased(buttonIndex); }
+
+bool HalGPIO::wasAnyReleased() const { return inputMgr.wasAnyReleased(); }
+
+unsigned long HalGPIO::getHeldTime() const { return inputMgr.getHeldTime(); }
+
+void HalGPIO::startDeepSleep() {
+  esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
+  // Ensure that the power button has been released to avoid immediately turning back on if you're holding it
+  while (inputMgr.isPressed(BTN_POWER)) {
+    delay(50);
+    inputMgr.update();
+  }
+  // Enter Deep Sleep
+  esp_deep_sleep_start();
+}
+
+int HalGPIO::getBatteryPercentage() const {
+  static const BatteryMonitor battery = BatteryMonitor(BAT_GPIO0);
+  return battery.readPercentage();
+}
+
+bool HalGPIO::isUsbConnected() const {
+  // U0RXD/GPIO20 reads HIGH when USB is connected
+  return digitalRead(UART0_RXD) == HIGH;
+}
+
+bool HalGPIO::isWakeupByPowerButton() const {
+  const auto wakeupCause = esp_sleep_get_wakeup_cause();
+  const auto resetReason = esp_reset_reason();
+  if (isUsbConnected()) {
+    return wakeupCause == ESP_SLEEP_WAKEUP_GPIO;
+  } else {
+    return (wakeupCause == ESP_SLEEP_WAKEUP_UNDEFINED) && (resetReason == ESP_RST_POWERON);
+  }
+}

lib/hal/HalGPIO.h

@@ -0,0 +1,61 @@
+#pragma once
+
+#include <Arduino.h>
+#include <BatteryMonitor.h>
+#include <InputManager.h>
+
+// Display SPI pins (custom pins for XteinkX4, not hardware SPI defaults)
+#define EPD_SCLK 8   // SPI Clock
+#define EPD_MOSI 10  // SPI MOSI (Master Out Slave In)
+#define EPD_CS 21    // Chip Select
+#define EPD_DC 4     // Data/Command
+#define EPD_RST 5    // Reset
+#define EPD_BUSY 6   // Busy
+
+#define SPI_MISO 7  // SPI MISO, shared between SD card and display (Master In Slave Out)
+
+#define BAT_GPIO0 0  // Battery voltage
+
+#define UART0_RXD 20  // Used for USB connection detection
+
+class HalGPIO {
+#if CROSSPOINT_EMULATED == 0
+  InputManager inputMgr;
+#endif
+
+ public:
+  HalGPIO() = default;
+
+  // Start button GPIO and setup SPI for screen and SD card
+  void begin();
+
+  // Button input methods
+  void update();
+  bool isPressed(uint8_t buttonIndex) const;
+  bool wasPressed(uint8_t buttonIndex) const;
+  bool wasAnyPressed() const;
+  bool wasReleased(uint8_t buttonIndex) const;
+  bool wasAnyReleased() const;
+  unsigned long getHeldTime() const;
+
+  // Setup wake up GPIO and enter deep sleep
+  void startDeepSleep();
+
+  // Get battery percentage (range 0-100)
+  int getBatteryPercentage() const;
+
+  // Check if USB is connected
+  bool isUsbConnected() const;
+
+  // Check if wakeup was caused by power button press
+  bool isWakeupByPowerButton() const;
+
+  // Button indices
+  static constexpr uint8_t BTN_BACK = 0;
+  static constexpr uint8_t BTN_CONFIRM = 1;
+  static constexpr uint8_t BTN_LEFT = 2;
+  static constexpr uint8_t BTN_RIGHT = 3;
+  static constexpr uint8_t BTN_UP = 4;
+  static constexpr uint8_t BTN_DOWN = 5;
+  static constexpr uint8_t BTN_POWER = 6;
+};

platformio.ini

@@ -2,7 +2,7 @@
 default_envs = default
 
 [crosspoint]
-version = 0.15.0
+version = 0.16.0
 
 [base]
 platform = espressif32 @ 6.12.0

src/MappedInputManager.cpp

@@ -19,20 +19,20 @@ struct SideLayoutMap {
 
 // Order matches CrossPointSettings::FRONT_BUTTON_LAYOUT.
 constexpr FrontLayoutMap kFrontLayouts[] = {
-    {InputManager::BTN_BACK, InputManager::BTN_CONFIRM, InputManager::BTN_LEFT, InputManager::BTN_RIGHT},
-    {InputManager::BTN_LEFT, InputManager::BTN_RIGHT, InputManager::BTN_BACK, InputManager::BTN_CONFIRM},
-    {InputManager::BTN_CONFIRM, InputManager::BTN_LEFT, InputManager::BTN_BACK, InputManager::BTN_RIGHT},
-    {InputManager::BTN_BACK, InputManager::BTN_CONFIRM, InputManager::BTN_RIGHT, InputManager::BTN_LEFT},
+    {HalGPIO::BTN_BACK, HalGPIO::BTN_CONFIRM, HalGPIO::BTN_LEFT, HalGPIO::BTN_RIGHT},
+    {HalGPIO::BTN_LEFT, HalGPIO::BTN_RIGHT, HalGPIO::BTN_BACK, HalGPIO::BTN_CONFIRM},
+    {HalGPIO::BTN_CONFIRM, HalGPIO::BTN_LEFT, HalGPIO::BTN_BACK, HalGPIO::BTN_RIGHT},
+    {HalGPIO::BTN_BACK, HalGPIO::BTN_CONFIRM, HalGPIO::BTN_RIGHT, HalGPIO::BTN_LEFT},
 };
 
 // Order matches CrossPointSettings::SIDE_BUTTON_LAYOUT.
 constexpr SideLayoutMap kSideLayouts[] = {
-    {InputManager::BTN_UP, InputManager::BTN_DOWN},
-    {InputManager::BTN_DOWN, InputManager::BTN_UP},
+    {HalGPIO::BTN_UP, HalGPIO::BTN_DOWN},
+    {HalGPIO::BTN_DOWN, HalGPIO::BTN_UP},
 };
 }  // namespace
 
-bool MappedInputManager::mapButton(const Button button, bool (InputManager::*fn)(uint8_t) const) const {
+bool MappedInputManager::mapButton(const Button button, bool (HalGPIO::*fn)(uint8_t) const) const {
   const auto frontLayout = static_cast<CrossPointSettings::FRONT_BUTTON_LAYOUT>(SETTINGS.frontButtonLayout);
   const auto sideLayout = static_cast<CrossPointSettings::SIDE_BUTTON_LAYOUT>(SETTINGS.sideButtonLayout);
   const auto& front = kFrontLayouts[frontLayout];
@@ -40,41 +40,39 @@ bool MappedInputManager::mapButton(const Button button, bool (InputManager::*fn)
 
   switch (button) {
     case Button::Back:
-      return (inputManager.*fn)(front.back);
+      return (gpio.*fn)(front.back);
     case Button::Confirm:
-      return (inputManager.*fn)(front.confirm);
+      return (gpio.*fn)(front.confirm);
     case Button::Left:
-      return (inputManager.*fn)(front.left);
+      return (gpio.*fn)(front.left);
     case Button::Right:
-      return (inputManager.*fn)(front.right);
+      return (gpio.*fn)(front.right);
     case Button::Up:
-      return (inputManager.*fn)(InputManager::BTN_UP);
+      return (gpio.*fn)(HalGPIO::BTN_UP);
     case Button::Down:
-      return (inputManager.*fn)(InputManager::BTN_DOWN);
+      return (gpio.*fn)(HalGPIO::BTN_DOWN);
     case Button::Power:
-      return (inputManager.*fn)(InputManager::BTN_POWER);
+      return (gpio.*fn)(HalGPIO::BTN_POWER);
     case Button::PageBack:
-      return (inputManager.*fn)(side.pageBack);
+      return (gpio.*fn)(side.pageBack);
     case Button::PageForward:
-      return (inputManager.*fn)(side.pageForward);
+      return (gpio.*fn)(side.pageForward);
   }
 
   return false;
 }
 
-bool MappedInputManager::wasPressed(const Button button) const { return mapButton(button, &InputManager::wasPressed); }
+bool MappedInputManager::wasPressed(const Button button) const { return mapButton(button, &HalGPIO::wasPressed); }
 
-bool MappedInputManager::wasReleased(const Button button) const {
-  return mapButton(button, &InputManager::wasReleased);
-}
+bool MappedInputManager::wasReleased(const Button button) const { return mapButton(button, &HalGPIO::wasReleased); }
 
-bool MappedInputManager::isPressed(const Button button) const { return mapButton(button, &InputManager::isPressed); }
+bool MappedInputManager::isPressed(const Button button) const { return mapButton(button, &HalGPIO::isPressed); }
 
-bool MappedInputManager::wasAnyPressed() const { return inputManager.wasAnyPressed(); }
+bool MappedInputManager::wasAnyPressed() const { return gpio.wasAnyPressed(); }
 
-bool MappedInputManager::wasAnyReleased() const { return inputManager.wasAnyReleased(); }
+bool MappedInputManager::wasAnyReleased() const { return gpio.wasAnyReleased(); }
 
-unsigned long MappedInputManager::getHeldTime() const { return inputManager.getHeldTime(); }
+unsigned long MappedInputManager::getHeldTime() const { return gpio.getHeldTime(); }
 
 MappedInputManager::Labels MappedInputManager::mapLabels(const char* back, const char* confirm, const char* previous,
                                                          const char* next) const {
@@ -91,4 +89,4 @@ MappedInputManager::Labels MappedInputManager::mapLabels(const char* back, const
     default:
       return {back, confirm, previous, next};
   }
-}
+}

src/MappedInputManager.h

@@ -1,6 +1,6 @@
 #pragma once
 
-#include <InputManager.h>
+#include <HalGPIO.h>
 
 class MappedInputManager {
  public:
@@ -13,7 +13,7 @@ class MappedInputManager {
     const char* btn4;
   };
 
-  explicit MappedInputManager(InputManager& inputManager) : inputManager(inputManager) {}
+  explicit MappedInputManager(HalGPIO& gpio) : gpio(gpio) {}
 
   bool wasPressed(Button button) const;
   bool wasReleased(Button button) const;
@@ -24,7 +24,7 @@ class MappedInputManager {
   Labels mapLabels(const char* back, const char* confirm, const char* previous, const char* next) const;
 
  private:
-  InputManager& inputManager;
+  HalGPIO& gpio;
 
-  bool mapButton(Button button, bool (InputManager::*fn)(uint8_t) const) const;
+  bool mapButton(Button button, bool (HalGPIO::*fn)(uint8_t) const) const;
 };

src/RecentBooksStore.cpp

@@ -7,22 +7,23 @@
 #include <algorithm>
 
 namespace {
-constexpr uint8_t RECENT_BOOKS_FILE_VERSION = 1;
+constexpr uint8_t RECENT_BOOKS_FILE_VERSION = 2;
 constexpr char RECENT_BOOKS_FILE[] = "/.crosspoint/recent.bin";
 constexpr int MAX_RECENT_BOOKS = 10;
 }  // namespace
 
 RecentBooksStore RecentBooksStore::instance;
 
-void RecentBooksStore::addBook(const std::string& path) {
+void RecentBooksStore::addBook(const std::string& path, const std::string& title, const std::string& author) {
   // Remove existing entry if present
-  auto it = std::find(recentBooks.begin(), recentBooks.end(), path);
+  auto it =
+      std::find_if(recentBooks.begin(), recentBooks.end(), [&](const RecentBook& book) { return book.path == path; });
   if (it != recentBooks.end()) {
     recentBooks.erase(it);
   }
 
   // Add to front
-  recentBooks.insert(recentBooks.begin(), path);
+  recentBooks.insert(recentBooks.begin(), {path, title, author});
 
   // Trim to max size
   if (recentBooks.size() > MAX_RECENT_BOOKS) {
@@ -46,7 +47,9 @@ bool RecentBooksStore::saveToFile() const {
   serialization::writePod(outputFile, count);
 
   for (const auto& book : recentBooks) {
-    serialization::writeString(outputFile, book);
+    serialization::writeString(outputFile, book.path);
+    serialization::writeString(outputFile, book.title);
+    serialization::writeString(outputFile, book.author);
   }
 
   outputFile.close();
@@ -63,24 +66,41 @@ bool RecentBooksStore::loadFromFile() {
   uint8_t version;
   serialization::readPod(inputFile, version);
   if (version != RECENT_BOOKS_FILE_VERSION) {
-    Serial.printf("[%lu] [RBS] Deserialization failed: Unknown version %u\n", millis(), version);
-    inputFile.close();
-    return false;
-  }
+    if (version == 1) {
+      // Old version, just read paths
+      uint8_t count;
+      serialization::readPod(inputFile, count);
+      recentBooks.clear();
+      recentBooks.reserve(count);
+      for (uint8_t i = 0; i < count; i++) {
+        std::string path;
+        serialization::readString(inputFile, path);
+        // Title and author will be empty, they will be filled when the book is
+        // opened again
+        recentBooks.push_back({path, "", ""});
+      }
+    } else {
+      Serial.printf("[%lu] [RBS] Deserialization failed: Unknown version %u\n", millis(), version);
+      inputFile.close();
+      return false;
+    }
+  } else {
+    uint8_t count;
+    serialization::readPod(inputFile, count);
 
-  uint8_t count;
-  serialization::readPod(inputFile, count);
+    recentBooks.clear();
+    recentBooks.reserve(count);
 
-  recentBooks.clear();
-  recentBooks.reserve(count);
-
-  for (uint8_t i = 0; i < count; i++) {
-    std::string path;
-    serialization::readString(inputFile, path);
-    recentBooks.push_back(path);
+    for (uint8_t i = 0; i < count; i++) {
+      std::string path, title, author;
+      serialization::readString(inputFile, path);
+      serialization::readString(inputFile, title);
+      serialization::readString(inputFile, author);
+      recentBooks.push_back({path, title, author});
+    }
   }
 
   inputFile.close();
-  Serial.printf("[%lu] [RBS] Recent books loaded from file (%d entries)\n", millis(), count);
+  Serial.printf("[%lu] [RBS] Recent books loaded from file (%d entries)\n", millis(), recentBooks.size());
   return true;
 }

src/RecentBooksStore.h

@@ -2,11 +2,19 @@
 #include <string>
 #include <vector>
 
+struct RecentBook {
+  std::string path;
+  std::string title;
+  std::string author;
+
+  bool operator==(const RecentBook& other) const { return path == other.path; }
+};
+
 class RecentBooksStore {
   // Static instance
   static RecentBooksStore instance;
 
-  std::vector<std::string> recentBooks;
+  std::vector<RecentBook> recentBooks;
 
  public:
   ~RecentBooksStore() = default;
@@ -14,11 +22,11 @@ class RecentBooksStore {
   // Get singleton instance
   static RecentBooksStore& getInstance() { return instance; }
 
-  // Add a book path to the recent list (moves to front if already exists)
-  void addBook(const std::string& path);
+  // Add a book to the recent list (moves to front if already exists)
+  void addBook(const std::string& path, const std::string& title, const std::string& author);
 
-  // Get the list of recent book paths (most recent first)
-  const std::vector<std::string>& getBooks() const { return recentBooks; }
+  // Get the list of recent books (most recent first)
+  const std::vector<RecentBook>& getBooks() const { return recentBooks; }
 
   // Get the count of recent books
   int getCount() const { return static_cast<int>(recentBooks.size()); }

src/activities/boot_sleep/SleepActivity.cpp

@@ -133,7 +133,7 @@ void SleepActivity::renderDefaultSleepScreen() const {
     renderer.invertScreen();
   }
 
-  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
 }
 
 void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
@@ -189,7 +189,7 @@ void SleepActivity::renderBitmapSleepScreen(const Bitmap& bitmap) const {
     renderer.invertScreen();
   }
 
-  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
 
   if (hasGreyscale) {
     bitmap.rewindToData();
@@ -280,5 +280,5 @@ void SleepActivity::renderCoverSleepScreen() const {
 
 void SleepActivity::renderBlankSleepScreen() const {
   renderer.clearScreen();
-  renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+  renderer.displayBuffer(HalDisplay::HALF_REFRESH);
 }

src/activities/home/MyLibraryActivity.cpp

@@ -16,6 +16,7 @@ namespace {
 constexpr int TAB_BAR_Y = 15;
 constexpr int CONTENT_START_Y = 60;
 constexpr int LINE_HEIGHT = 30;
+constexpr int RECENTS_LINE_HEIGHT = 65;  // Increased for two-line items
 constexpr int LEFT_MARGIN = 20;
 constexpr int RIGHT_MARGIN = 40;  // Extra space for scroll indicator
 
@@ -47,7 +48,7 @@ int MyLibraryActivity::getPageItems() const {
 
 int MyLibraryActivity::getCurrentItemCount() const {
   if (currentTab == Tab::Recent) {
-    return static_cast<int>(bookTitles.size());
+    return static_cast<int>(recentBooks.size());
   }
   return static_cast<int>(files.size());
 }
@@ -65,34 +66,16 @@ int MyLibraryActivity::getCurrentPage() const {
 }
 
 void MyLibraryActivity::loadRecentBooks() {
-  constexpr size_t MAX_RECENT_BOOKS = 20;
-
-  bookTitles.clear();
-  bookPaths.clear();
+  recentBooks.clear();
   const auto& books = RECENT_BOOKS.getBooks();
-  bookTitles.reserve(std::min(books.size(), MAX_RECENT_BOOKS));
-  bookPaths.reserve(std::min(books.size(), MAX_RECENT_BOOKS));
-
-  for (const auto& path : books) {
-    // Limit to maximum number of recent books
-    if (bookTitles.size() >= MAX_RECENT_BOOKS) {
-      break;
-    }
+  recentBooks.reserve(books.size());
 
+  for (const auto& book : books) {
     // Skip if file no longer exists
-    if (!SdMan.exists(path.c_str())) {
+    if (!SdMan.exists(book.path.c_str())) {
       continue;
     }
-
-    // Extract filename from path for display
-    std::string title = path;
-    const size_t lastSlash = title.find_last_of('/');
-    if (lastSlash != std::string::npos) {
-      title = title.substr(lastSlash + 1);
-    }
-
-    bookTitles.push_back(title);
-    bookPaths.push_back(path);
+    recentBooks.push_back(book);
   }
 }
 
@@ -176,8 +159,6 @@ void MyLibraryActivity::onExit() {
   vSemaphoreDelete(renderingMutex);
   renderingMutex = nullptr;
 
-  bookTitles.clear();
-  bookPaths.clear();
   files.clear();
 }
 
@@ -207,8 +188,8 @@ void MyLibraryActivity::loop() {
   // Confirm button - open selected item
   if (mappedInput.wasReleased(MappedInputManager::Button::Confirm)) {
     if (currentTab == Tab::Recent) {
-      if (!bookPaths.empty() && selectorIndex < static_cast<int>(bookPaths.size())) {
-        onSelectBook(bookPaths[selectorIndex], currentTab);
+      if (!recentBooks.empty() && selectorIndex < static_cast<int>(recentBooks.size())) {
+        onSelectBook(recentBooks[selectorIndex].path, currentTab);
       }
     } else {
       // Files tab
@@ -333,7 +314,7 @@ void MyLibraryActivity::render() const {
 void MyLibraryActivity::renderRecentTab() const {
   const auto pageWidth = renderer.getScreenWidth();
   const int pageItems = getPageItems();
-  const int bookCount = static_cast<int>(bookTitles.size());
+  const int bookCount = static_cast<int>(recentBooks.size());
 
   if (bookCount == 0) {
     renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, CONTENT_START_Y, "No recent books");
@@ -343,14 +324,37 @@ void MyLibraryActivity::renderRecentTab() const {
   const auto pageStartIndex = selectorIndex / pageItems * pageItems;
 
   // Draw selection highlight
-  renderer.fillRect(0, CONTENT_START_Y + (selectorIndex % pageItems) * LINE_HEIGHT - 2, pageWidth - RIGHT_MARGIN,
-                    LINE_HEIGHT);
+  renderer.fillRect(0, CONTENT_START_Y + (selectorIndex % pageItems) * RECENTS_LINE_HEIGHT - 2,
+                    pageWidth - RIGHT_MARGIN, RECENTS_LINE_HEIGHT);
 
   // Draw items
   for (int i = pageStartIndex; i < bookCount && i < pageStartIndex + pageItems; i++) {
-    auto item = renderer.truncatedText(UI_10_FONT_ID, bookTitles[i].c_str(), pageWidth - LEFT_MARGIN - RIGHT_MARGIN);
-    renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, CONTENT_START_Y + (i % pageItems) * LINE_HEIGHT, item.c_str(),
-                      i != selectorIndex);
+    const auto& book = recentBooks[i];
+    const int y = CONTENT_START_Y + (i % pageItems) * RECENTS_LINE_HEIGHT;
+
+    // Line 1: Title
+    std::string title = book.title;
+    if (title.empty()) {
+      // Fallback for older entries or files without metadata
+      title = book.path;
+      const size_t lastSlash = title.find_last_of('/');
+      if (lastSlash != std::string::npos) {
+        title = title.substr(lastSlash + 1);
+      }
+      const size_t dot = title.find_last_of('.');
+      if (dot != std::string::npos) {
+        title.resize(dot);
+      }
+    }
+    auto truncatedTitle = renderer.truncatedText(UI_12_FONT_ID, title.c_str(), pageWidth - LEFT_MARGIN - RIGHT_MARGIN);
+    renderer.drawText(UI_12_FONT_ID, LEFT_MARGIN, y + 2, truncatedTitle.c_str(), i != selectorIndex);
+
+    // Line 2: Author
+    if (!book.author.empty()) {
+      auto truncatedAuthor =
+          renderer.truncatedText(UI_10_FONT_ID, book.author.c_str(), pageWidth - LEFT_MARGIN - RIGHT_MARGIN);
+      renderer.drawText(UI_10_FONT_ID, LEFT_MARGIN, y + 32, truncatedAuthor.c_str(), i != selectorIndex);
+    }
   }
 }
 

src/activities/home/MyLibraryActivity.h

@@ -8,6 +8,7 @@
 #include <vector>
 
 #include "../Activity.h"
+#include "RecentBooksStore.h"
 
 class MyLibraryActivity final : public Activity {
  public:
@@ -22,8 +23,7 @@ class MyLibraryActivity final : public Activity {
   bool updateRequired = false;
 
   // Recent tab state
-  std::vector<std::string> bookTitles;  // Display titles for each book
-  std::vector<std::string> bookPaths;   // Paths for each visible book (excludes missing)
+  std::vector<RecentBook> recentBooks;
 
   // Files tab state (from FileSelectionActivity)
   std::string basepath = "/";

src/activities/reader/EpubReaderActivity.cpp

@@ -85,7 +85,7 @@ void EpubReaderActivity::onEnter() {
   // Save current epub as last opened epub and add to recent books
   APP_STATE.openEpubPath = epub->getPath();
   APP_STATE.saveToFile();
-  RECENT_BOOKS.addBook(epub->getPath());
+  RECENT_BOOKS.addBook(epub->getPath(), epub->getTitle(), epub->getAuthor());
 
   // Trigger first update
   updateRequired = true;
@@ -345,7 +345,7 @@ void EpubReaderActivity::renderScreen() {
       auto progressCallback = [this, barX, barY, barWidth, barHeight](int progress) {
         const int fillWidth = (barWidth - 2) * progress / 100;
         renderer.fillRect(barX + 1, barY + 1, fillWidth, barHeight - 2, true);
-        renderer.displayBuffer(EInkDisplay::FAST_REFRESH);
+        renderer.displayBuffer(HalDisplay::FAST_REFRESH);
       };
 
       if (!section->createSectionFile(SETTINGS.getReaderFontId(), SETTINGS.getReaderLineCompression(),
@@ -428,7 +428,7 @@ void EpubReaderActivity::renderContents(std::unique_ptr<Page> page, const int or
   page->render(renderer, SETTINGS.getReaderFontId(), orientedMarginLeft, orientedMarginTop);
   renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
   if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
     pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();

src/activities/reader/TxtReaderActivity.cpp

@@ -60,7 +60,7 @@ void TxtReaderActivity::onEnter() {
   // Save current txt as last opened file and add to recent books
   APP_STATE.openEpubPath = txt->getPath();
   APP_STATE.saveToFile();
-  RECENT_BOOKS.addBook(txt->getPath());
+  RECENT_BOOKS.addBook(txt->getPath(), "", "");
 
   // Trigger first update
   updateRequired = true;
@@ -256,7 +256,7 @@ void TxtReaderActivity::buildPageIndex() {
       // Fill progress bar
       const int fillWidth = (barWidth - 2) * progressPercent / 100;
       renderer.fillRect(barX + 1, barY + 1, fillWidth, barHeight - 2, true);
-      renderer.displayBuffer(EInkDisplay::FAST_REFRESH);
+      renderer.displayBuffer(HalDisplay::FAST_REFRESH);
     }
 
     // Yield to other tasks periodically
@@ -484,7 +484,7 @@ void TxtReaderActivity::renderPage() {
   renderStatusBar(orientedMarginRight, orientedMarginBottom, orientedMarginLeft);
 
   if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
     pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();

src/activities/reader/XtcReaderActivity.cpp

@@ -45,7 +45,7 @@ void XtcReaderActivity::onEnter() {
   // Save current XTC as last opened book and add to recent books
   APP_STATE.openEpubPath = xtc->getPath();
   APP_STATE.saveToFile();
-  RECENT_BOOKS.addBook(xtc->getPath());
+  RECENT_BOOKS.addBook(xtc->getPath(), xtc->getTitle(), xtc->getAuthor());
 
   // Trigger first update
   updateRequired = true;
@@ -276,7 +276,7 @@ void XtcReaderActivity::renderPage() {
 
     // Display BW with conditional refresh based on pagesUntilFullRefresh
     if (pagesUntilFullRefresh <= 1) {
-      renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+      renderer.displayBuffer(HalDisplay::HALF_REFRESH);
       pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
     } else {
       renderer.displayBuffer();
@@ -356,7 +356,7 @@ void XtcReaderActivity::renderPage() {
 
   // Display with appropriate refresh
   if (pagesUntilFullRefresh <= 1) {
-    renderer.displayBuffer(EInkDisplay::HALF_REFRESH);
+    renderer.displayBuffer(HalDisplay::HALF_REFRESH);
     pagesUntilFullRefresh = SETTINGS.getRefreshFrequency();
   } else {
     renderer.displayBuffer();

src/activities/util/FullScreenMessageActivity.h

@@ -1,6 +1,6 @@
 #pragma once
-#include <EInkDisplay.h>
 #include <EpdFontFamily.h>
+#include <HalDisplay.h>
 
 #include <string>
 #include <utility>
@@ -10,12 +10,12 @@
 class FullScreenMessageActivity final : public Activity {
   std::string text;
   EpdFontFamily::Style style;
-  EInkDisplay::RefreshMode refreshMode;
+  HalDisplay::RefreshMode refreshMode;
 
  public:
   explicit FullScreenMessageActivity(GfxRenderer& renderer, MappedInputManager& mappedInput, std::string text,
                                      const EpdFontFamily::Style style = EpdFontFamily::REGULAR,
-                                     const EInkDisplay::RefreshMode refreshMode = EInkDisplay::FAST_REFRESH)
+                                     const HalDisplay::RefreshMode refreshMode = HalDisplay::FAST_REFRESH)
       : Activity("FullScreenMessage", renderer, mappedInput),
         text(std::move(text)),
         style(style),

src/activities/util/KeyboardEntryActivity.cpp

@@ -13,6 +13,9 @@ const char* const KeyboardEntryActivity::keyboard[NUM_ROWS] = {
 const char* const KeyboardEntryActivity::keyboardShift[NUM_ROWS] = {"~!@#$%^&*()_+", "QWERTYUIOP{}|", "ASDFGHJKL:\"",
                                                                     "ZXCVBNM<>?", "SPECIAL ROW"};
 
+// Shift state strings
+const char* const KeyboardEntryActivity::shiftString[3] = {"shift", "SHIFT", "LOCK"};
+
 void KeyboardEntryActivity::taskTrampoline(void* param) {
   auto* self = static_cast<KeyboardEntryActivity*>(param);
   self->displayTaskLoop();
@@ -80,7 +83,7 @@ int KeyboardEntryActivity::getRowLength(const int row) const {
 }
 
 char KeyboardEntryActivity::getSelectedChar() const {
-  const char* const* layout = shiftActive ? keyboardShift : keyboard;
+  const char* const* layout = shiftState ? keyboardShift : keyboard;
 
   if (selectedRow < 0 || selectedRow >= NUM_ROWS) return '\0';
   if (selectedCol < 0 || selectedCol >= getRowLength(selectedRow)) return '\0';
@@ -92,8 +95,8 @@ void KeyboardEntryActivity::handleKeyPress() {
   // Handle special row (bottom row with shift, space, backspace, done)
   if (selectedRow == SPECIAL_ROW) {
     if (selectedCol >= SHIFT_COL && selectedCol < SPACE_COL) {
-      // Shift toggle
-      shiftActive = !shiftActive;
+      // Shift toggle (0 = lower case, 1 = upper case, 2 = shift lock)
+      shiftState = (shiftState + 1) % 3;
       return;
     }
 
@@ -130,9 +133,9 @@ void KeyboardEntryActivity::handleKeyPress() {
 
   if (maxLength == 0 || text.length() < maxLength) {
     text += c;
-    // Auto-disable shift after typing a letter
-    if (shiftActive && ((c >= 'A' && c <= 'Z') || (c >= 'a' && c <= 'z'))) {
-      shiftActive = false;
+    // Auto-disable shift after typing a character in non-lock mode
+    if (shiftState == 1) {
+      shiftState = 0;
     }
   }
 }
@@ -256,8 +259,9 @@ void KeyboardEntryActivity::render() const {
   renderer.drawCenteredText(UI_10_FONT_ID, startY, title.c_str());
 
   // Draw input field
-  const int inputY = startY + 22;
-  renderer.drawText(UI_10_FONT_ID, 10, inputY, "[");
+  const int inputStartY = startY + 22;
+  int inputEndY = startY + 22;
+  renderer.drawText(UI_10_FONT_ID, 10, inputStartY, "[");
 
   std::string displayText;
   if (isPassword) {
@@ -269,24 +273,34 @@ void KeyboardEntryActivity::render() const {
   // Show cursor at end
   displayText += "_";
 
-  // Truncate if too long for display - use actual character width from font
-  int approxCharWidth = renderer.getSpaceWidth(UI_10_FONT_ID);
-  if (approxCharWidth < 1) approxCharWidth = 8;  // Fallback to approximate width
-  const int maxDisplayLen = (pageWidth - 40) / approxCharWidth;
-  if (displayText.length() > static_cast<size_t>(maxDisplayLen)) {
-    displayText = "..." + displayText.substr(displayText.length() - maxDisplayLen + 3);
-  }
+  // Render input text across multiple lines
+  int lineStartIdx = 0;
+  int lineEndIdx = displayText.length();
+  while (true) {
+    std::string lineText = displayText.substr(lineStartIdx, lineEndIdx - lineStartIdx);
+    const int textWidth = renderer.getTextWidth(UI_10_FONT_ID, lineText.c_str());
+    if (textWidth <= pageWidth - 40) {
+      renderer.drawText(UI_10_FONT_ID, 20, inputEndY, lineText.c_str());
+      if (lineEndIdx == displayText.length()) {
+        break;
+      }
 
-  renderer.drawText(UI_10_FONT_ID, 20, inputY, displayText.c_str());
-  renderer.drawText(UI_10_FONT_ID, pageWidth - 15, inputY, "]");
+      inputEndY += renderer.getLineHeight(UI_10_FONT_ID);
+      lineStartIdx = lineEndIdx;
+      lineEndIdx = displayText.length();
+    } else {
+      lineEndIdx -= 1;
+    }
+  }
+  renderer.drawText(UI_10_FONT_ID, pageWidth - 15, inputEndY, "]");
 
   // Draw keyboard - use compact spacing to fit 5 rows on screen
-  const int keyboardStartY = inputY + 25;
+  const int keyboardStartY = inputEndY + 25;
   constexpr int keyWidth = 18;
   constexpr int keyHeight = 18;
   constexpr int keySpacing = 3;
 
-  const char* const* layout = shiftActive ? keyboardShift : keyboard;
+  const char* const* layout = shiftState ? keyboardShift : keyboard;
 
   // Calculate left margin to center the longest row (13 keys)
   constexpr int maxRowWidth = KEYS_PER_ROW * (keyWidth + keySpacing);
@@ -307,7 +321,7 @@ void KeyboardEntryActivity::render() const {
 
       // SHIFT key (logical col 0, spans 2 key widths)
       const bool shiftSelected = (selectedRow == 4 && selectedCol >= SHIFT_COL && selectedCol < SPACE_COL);
-      renderItemWithSelector(currentX + 2, rowY, shiftActive ? "SHIFT" : "shift", shiftSelected);
+      renderItemWithSelector(currentX + 2, rowY, shiftString[shiftState], shiftSelected);
       currentX += 2 * (keyWidth + keySpacing);
 
       // Space bar (logical cols 2-6, spans 5 key widths)

src/activities/util/KeyboardEntryActivity.h

@@ -70,7 +70,7 @@ class KeyboardEntryActivity : public Activity {
   // Keyboard state
   int selectedRow = 0;
   int selectedCol = 0;
-  bool shiftActive = false;
+  int shiftState = 0;  // 0 = lower case, 1 = upper case, 2 = shift lock)
 
   // Callbacks
   OnCompleteCallback onComplete;
@@ -81,6 +81,7 @@ class KeyboardEntryActivity : public Activity {
   static constexpr int KEYS_PER_ROW = 13;  // Max keys per row (rows 0 and 1 have 13 keys)
   static const char* const keyboard[NUM_ROWS];
   static const char* const keyboardShift[NUM_ROWS];
+  static const char* const shiftString[3];
 
   // Special key positions (bottom row)
   static constexpr int SPECIAL_ROW = 4;

src/main.cpp

@@ -1,8 +1,8 @@
 #include <Arduino.h>
-#include <EInkDisplay.h>
 #include <Epub.h>
 #include <GfxRenderer.h>
-#include <InputManager.h>
+#include <HalDisplay.h>
+#include <HalGPIO.h>
 #include <SDCardManager.h>
 #include <SPI.h>
 #include <builtinFonts/all.h>
@@ -26,23 +26,10 @@
 #include "activities/util/FullScreenMessageActivity.h"
 #include "fontIds.h"
 
-#define SPI_FQ 40000000
-// Display SPI pins (custom pins for XteinkX4, not hardware SPI defaults)
-#define EPD_SCLK 8   // SPI Clock
-#define EPD_MOSI 10  // SPI MOSI (Master Out Slave In)
-#define EPD_CS 21    // Chip Select
-#define EPD_DC 4     // Data/Command
-#define EPD_RST 5    // Reset
-#define EPD_BUSY 6   // Busy
-
-#define UART0_RXD 20  // Used for USB connection detection
-
-#define SD_SPI_MISO 7
-
-EInkDisplay einkDisplay(EPD_SCLK, EPD_MOSI, EPD_CS, EPD_DC, EPD_RST, EPD_BUSY);
-InputManager inputManager;
-MappedInputManager mappedInputManager(inputManager);
-GfxRenderer renderer(einkDisplay);
+HalDisplay display;
+HalGPIO gpio;
+MappedInputManager mappedInputManager(gpio);
+GfxRenderer renderer(display);
 Activity* currentActivity;
 
 // Fonts
@@ -170,21 +157,20 @@ void verifyPowerButtonDuration() {
   const uint16_t calibratedPressDuration =
       (calibration < SETTINGS.getPowerButtonDuration()) ? SETTINGS.getPowerButtonDuration() - calibration : 1;
 
-  inputManager.update();
-  // Verify the user has actually pressed
+  gpio.update();
   // Needed because inputManager.isPressed() may take up to ~500ms to return the correct state
-  while (!inputManager.isPressed(InputManager::BTN_POWER) && millis() - start < 1000) {
+  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.
-    inputManager.update();
+    gpio.update();
   }
 
   t2 = millis();
-  if (inputManager.isPressed(InputManager::BTN_POWER)) {
+  if (gpio.isPressed(HalGPIO::BTN_POWER)) {
     do {
       delay(10);
-      inputManager.update();
-    } while (inputManager.isPressed(InputManager::BTN_POWER) && inputManager.getHeldTime() < calibratedPressDuration);
-    abort = inputManager.getHeldTime() < calibratedPressDuration;
+      gpio.update();
+    } while (gpio.isPressed(HalGPIO::BTN_POWER) && gpio.getHeldTime() < calibratedPressDuration);
+    abort = gpio.getHeldTime() < calibratedPressDuration;
   } else {
     abort = true;
   }
@@ -192,16 +178,15 @@ void verifyPowerButtonDuration() {
   if (abort) {
     // Button released too early. Returning to sleep.
     // IMPORTANT: Re-arm the wakeup trigger before sleeping again
-    esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
-    esp_deep_sleep_start();
+    gpio.startDeepSleep();
   }
 }
 
 void waitForPowerRelease() {
-  inputManager.update();
-  while (inputManager.isPressed(InputManager::BTN_POWER)) {
+  gpio.update();
+  while (gpio.isPressed(HalGPIO::BTN_POWER)) {
     delay(50);
-    inputManager.update();
+    gpio.update();
   }
 }
 
@@ -210,14 +195,11 @@ void enterDeepSleep() {
   exitActivity();
   enterNewActivity(new SleepActivity(renderer, mappedInputManager));
 
-  einkDisplay.deepSleep();
+  display.deepSleep();
   Serial.printf("[%lu] [   ] Power button press calibration value: %lu ms\n", millis(), t2 - t1);
   Serial.printf("[%lu] [   ] Entering deep sleep.\n", millis());
-  esp_deep_sleep_enable_gpio_wakeup(1ULL << InputManager::POWER_BUTTON_PIN, ESP_GPIO_WAKEUP_GPIO_LOW);
-  // Ensure that the power button has been released to avoid immediately turning back on if you're holding it
-  waitForPowerRelease();
-  // Enter Deep Sleep
-  esp_deep_sleep_start();
+
+  gpio.startDeepSleep();
 }
 
 void onGoHome();
@@ -261,7 +243,7 @@ void onGoHome() {
 }
 
 void setupDisplayAndFonts() {
-  einkDisplay.begin();
+  display.begin();
   Serial.printf("[%lu] [   ] Display initialized\n", millis());
   renderer.insertFont(BOOKERLY_14_FONT_ID, bookerly14FontFamily);
 #ifndef OMIT_FONTS
@@ -284,27 +266,13 @@ void setupDisplayAndFonts() {
   Serial.printf("[%lu] [   ] Fonts setup\n", millis());
 }
 
-bool isUsbConnected() {
-  // U0RXD/GPIO20 reads HIGH when USB is connected
-  return digitalRead(UART0_RXD) == HIGH;
-}
-
-bool isWakeupByPowerButton() {
-  const auto wakeupCause = esp_sleep_get_wakeup_cause();
-  const auto resetReason = esp_reset_reason();
-  if (isUsbConnected()) {
-    return wakeupCause == ESP_SLEEP_WAKEUP_GPIO;
-  } else {
-    return (wakeupCause == ESP_SLEEP_WAKEUP_UNDEFINED) && (resetReason == ESP_RST_POWERON);
-  }
-}
-
 void setup() {
   t1 = millis();
 
+  gpio.begin();
+
   // Only start serial if USB connected
-  pinMode(UART0_RXD, INPUT);
-  if (isUsbConnected()) {
+  if (gpio.isUsbConnected()) {
     Serial.begin(115200);
     // Wait up to 3 seconds for Serial to be ready to catch early logs
     unsigned long start = millis();
@@ -313,13 +281,6 @@ void setup() {
     }
   }
 
-  inputManager.begin();
-  // Initialize pins
-  pinMode(BAT_GPIO0, INPUT);
-
-  // Initialize SPI with custom pins
-  SPI.begin(EPD_SCLK, SD_SPI_MISO, EPD_MOSI, EPD_CS);
-
   // SD Card Initialization
   // We need 6 open files concurrently when parsing a new chapter
   if (!SdMan.begin()) {
@@ -333,7 +294,7 @@ void setup() {
   SETTINGS.loadFromFile();
   KOREADER_STORE.loadFromFile();
 
-  if (isWakeupByPowerButton()) {
+  if (gpio.isWakeupByPowerButton()) {
     // For normal wakeups, verify power button press duration
     Serial.printf("[%lu] [   ] Verifying power button press duration\n", millis());
     verifyPowerButtonDuration();
@@ -370,7 +331,7 @@ void loop() {
   const unsigned long loopStartTime = millis();
   static unsigned long lastMemPrint = 0;
 
-  inputManager.update();
+  gpio.update();
 
   if (Serial && millis() - lastMemPrint >= 10000) {
     Serial.printf("[%lu] [MEM] Free: %d bytes, Total: %d bytes, Min Free: %d bytes\n", millis(), ESP.getFreeHeap(),
@@ -380,8 +341,7 @@ void loop() {
 
   // Check for any user activity (button press or release) or active background work
   static unsigned long lastActivityTime = millis();
-  if (inputManager.wasAnyPressed() || inputManager.wasAnyReleased() ||
-      (currentActivity && currentActivity->preventAutoSleep())) {
+  if (gpio.wasAnyPressed() || gpio.wasAnyReleased() || (currentActivity && currentActivity->preventAutoSleep())) {
     lastActivityTime = millis();  // Reset inactivity timer
   }
 
@@ -393,8 +353,7 @@ void loop() {
     return;
   }
 
-  if (inputManager.isPressed(InputManager::BTN_POWER) &&
-      inputManager.getHeldTime() > SETTINGS.getPowerButtonDuration()) {
+  if (gpio.isPressed(HalGPIO::BTN_POWER) && gpio.getHeldTime() > SETTINGS.getPowerButtonDuration()) {
     enterDeepSleep();
     // This should never be hit as `enterDeepSleep` calls esp_deep_sleep_start
     return;