feat(screenshot): extend e-ink screenshot support via GxEPD2 patch

- Add lib/GxEPD2-patch/src/GxEPD2_BW.h: local patched copy of GxEPD2_BW.h
  that exposes getBuffer()/getBufferSize() under ENABLE_SCREENSHOT guard.
  Include guard (_GxEPD2_BW_H_) prevents double-inclusion of the installed
  library version.

- GxEPDDisplay.h: use patched header via relative include when
  ENABLE_SCREENSHOT so the patch takes precedence over the installed lib
  (PlatformIO adds library paths before -I build_flags).

- DisplayDriver.h: add virtual getBuffer()/getBufferSize()/getDisplayType()
  defaults (nullptr/0/0) under ENABLE_SCREENSHOT.

- SH1106Display.h / SSD1306Display.h / GxEPDDisplay.h: add concrete overrides;
  getDisplayType() returns 0 (OLED) or 1 (e-ink).

- MyMesh.cpp/h: replace fragile C-cast with virtual dispatch in
  handleScreenshotRequest(); extend 5-byte header to 6 bytes by appending
  display_type so the host tool can decode the correct pixel layout.

- tools/screenshot.py: parse 6-byte header; add eink_buffer_to_image()
  that decodes the row-major MSB-first GxEPD2 buffer with DISPLAY_ROTATION=1
  (phys_x = 127-ly, phys_y = lx); dispatch on display_type.

- variants/wio-tracker-l1-eink/platformio.ini: add
  [env:WioTrackerL1Eink_companion_dual_dev] with ENABLE_SCREENSHOT.
- variants/wio-tracker-l1/platformio.ini: unchanged (OLED env already exists).

Builds verified: WioTrackerL1Eink_companion_dual_dev SUCCESS,
                 WioTrackerL1Eink_companion_radio_ble SUCCESS (unaffected).

Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>

examples/companion_radio/MyMesh.cpp

@@ -2084,28 +2084,12 @@ void MyMesh::handleScreenshotRequest() {
         return;
     }
 
-    uint8_t* buffer = nullptr;
+    const uint8_t* buffer = display->getBuffer();
-    int bufferSize = 0;
+    uint16_t bufferSize = display->getBufferSize();
-    
-    // Try SH1106Display first (used by Wio L1)
-    // Use C-style cast since RTTI is disabled (-fno-rtti)
-    SH1106Display* sh1106 = (SH1106Display*)display;
-    if (sh1106) {
-        buffer = sh1106->getBuffer();
-        bufferSize = (display->width() * display->height()) / 8;
-    } else {
-        // Fallback: try SSD1306Display
-        SSD1306Display* ssd1306 = (SSD1306Display*)display;
-        if (ssd1306) {
-            buffer = ssd1306->getBuffer();
-            bufferSize = (display->width() * display->height()) / 8;
-        }
-    }
 
     if (buffer && bufferSize > 0) {
         sendScreenshotResponse(display, buffer, bufferSize);
     } else {
-        // No supported display type
         writeErrFrame(ERR_CODE_UNSUPPORTED_CMD);
     }
     #else
@@ -2113,23 +2097,23 @@ void MyMesh::handleScreenshotRequest() {
     #endif
 }
 
-void MyMesh::sendScreenshotResponse(DisplayDriver* display, uint8_t* buffer, int bufferSize) {
+void MyMesh::sendScreenshotResponse(DisplayDriver* display, const uint8_t* buffer, uint16_t bufferSize) {
-    // MAX_FRAME_SIZE is 172 bytes, but we need to send 1026 bytes (3 header + 1024 buffer)
+    // Frame format: RESP_CODE_SCREENSHOT, width, height, chunk_idx, total_chunks, display_type, [data]
-    // We need to split into multiple frames
+    // display_type: 0=OLED (page-based), 1=e-ink (row-major, MSB-first, 1=white/0=black)
-    // Frame format: RESP_CODE_SCREENSHOT, width, height, chunk_index, total_chunks, [chunk_data...]
+    const int HEADER_SIZE = 6;
-    
+    const int MAX_DATA_PER_FRAME = MAX_FRAME_SIZE - HEADER_SIZE;
-    const int MAX_DATA_PER_FRAME = MAX_FRAME_SIZE - 5; // 5 bytes header
     int totalChunks = (bufferSize + MAX_DATA_PER_FRAME - 1) / MAX_DATA_PER_FRAME;
 
     for (int chunkIdx = 0; chunkIdx < totalChunks; chunkIdx++) {
         int i = 0;
         out_frame[i++] = RESP_CODE_SCREENSHOT;
-        out_frame[i++] = display->width();
+        out_frame[i++] = (uint8_t)display->width();
-        out_frame[i++] = display->height();
+        out_frame[i++] = (uint8_t)display->height();
-        out_frame[i++] = chunkIdx;
+        out_frame[i++] = (uint8_t)chunkIdx;
-        out_frame[i++] = totalChunks;
+        out_frame[i++] = (uint8_t)totalChunks;
+        out_frame[i++] = display->getDisplayType();
 
-        int chunkSize = min(MAX_DATA_PER_FRAME, bufferSize - chunkIdx * MAX_DATA_PER_FRAME);
+        int chunkSize = min(MAX_DATA_PER_FRAME, (int)bufferSize - chunkIdx * MAX_DATA_PER_FRAME);
         memcpy(&out_frame[i], buffer + chunkIdx * MAX_DATA_PER_FRAME, chunkSize);
         i += chunkSize;
 

examples/companion_radio/MyMesh.h

@@ -229,7 +229,7 @@ private:
   bool isValidClientRepeatFreq(uint32_t f) const;
 #ifdef ENABLE_SCREENSHOT
   void handleScreenshotRequest();
-  void sendScreenshotResponse(DisplayDriver* display, uint8_t* buffer, int bufferSize);
+  void sendScreenshotResponse(DisplayDriver* display, const uint8_t* buffer, uint16_t bufferSize);
 #endif
 
   UITask* getUITask() { return (UITask*)_ui; }

lib/GxEPD2-patch/src/GxEPD2_BW.h

@@ -0,0 +1,765 @@
+// Display Library for SPI e-paper panels from Dalian Good Display and boards from Waveshare.
+// Requires HW SPI and Adafruit_GFX. Caution: the e-paper panels require 3.3V supply AND data lines!
+//
+// Display Library based on Demo Example from Good Display: https://www.good-display.com/companyfile/32/
+//
+// Author: Jean-Marc Zingg
+//
+// Version: see library.properties
+//
+// Library: https://github.com/ZinggJM/GxEPD2
+
+#ifndef _GxEPD2_BW_H_
+#define _GxEPD2_BW_H_
+
+// uncomment next line to use class GFX of library GFX_Root instead of Adafruit_GFX
+//#include <GFX.h>
+
+#ifndef ENABLE_GxEPD2_GFX
+// default is off
+#define ENABLE_GxEPD2_GFX 0
+#endif
+
+#if ENABLE_GxEPD2_GFX
+#include "GxEPD2_GFX.h"
+#define GxEPD2_GFX_BASE_CLASS GxEPD2_GFX
+#elif defined(_GFX_H_)
+#define GxEPD2_GFX_BASE_CLASS GFX
+#else
+#include <Adafruit_GFX.h>
+#define GxEPD2_GFX_BASE_CLASS Adafruit_GFX
+#endif
+
+#include "GxEPD2_EPD.h"
+
+// for __has_include see https://en.cppreference.com/w/cpp/preprocessor/include
+// see also https://gcc.gnu.org/onlinedocs/cpp/_005f_005fhas_005finclude.html
+// #if !defined(__has_include) || __has_include("epd/GxEPD2_102.h") is not portable!
+
+#if defined __has_include
+#  if __has_include("GxEPD2.h")
+#    // __has_include can be used
+#  else
+#    // __has_include doesn't work for us, include anyway
+#    undef __has_include
+#    define __has_include(x) true
+#  endif
+#else
+#  // no __has_include, include anyway
+#  define __has_include(x) true
+#endif
+
+#if __has_include("epd/GxEPD2_102.h")
+#include "epd/GxEPD2_102.h"
+#endif
+#if __has_include("epd/GxEPD2_150_BN.h")
+#include "epd/GxEPD2_150_BN.h"
+#endif
+#if __has_include("epd/GxEPD2_154.h")
+#include "epd/GxEPD2_154.h"
+#endif
+#if __has_include("epd/GxEPD2_154_D67.h")
+#include "epd/GxEPD2_154_D67.h"
+#endif
+#if __has_include("epd/GxEPD2_154_T8.h")
+#include "epd/GxEPD2_154_T8.h"
+#endif
+#if __has_include("epd/GxEPD2_154_M09.h")
+#include "epd/GxEPD2_154_M09.h"
+#endif
+#if __has_include("epd/GxEPD2_154_M10.h")
+#include "epd/GxEPD2_154_M10.h"
+#endif
+#if __has_include("gdey/GxEPD2_154_GDEY0154D67.h")
+#include "gdey/GxEPD2_154_GDEY0154D67.h"
+#endif
+#if __has_include("epd/GxEPD2_213.h")
+#include "epd/GxEPD2_213.h"
+#endif
+#if __has_include("epd/GxEPD2_213_B72.h")
+#include "epd/GxEPD2_213_B72.h"
+#endif
+#if __has_include("epd/GxEPD2_213_B73.h")
+#include "epd/GxEPD2_213_B73.h"
+#endif
+#if __has_include("epd/GxEPD2_213_B74.h")
+#include "epd/GxEPD2_213_B74.h"
+#endif
+#if __has_include("epd/GxEPD2_213_flex.h")
+#include "epd/GxEPD2_213_flex.h"
+#endif
+#if __has_include("epd/GxEPD2_213_M21.h")
+#include "epd/GxEPD2_213_M21.h"
+#endif
+#if __has_include("epd/GxEPD2_213_T5D.h")
+#include "epd/GxEPD2_213_T5D.h"
+#endif
+#if __has_include("epd/GxEPD2_213_BN.h")
+#include "epd/GxEPD2_213_BN.h"
+#endif
+#if __has_include("gdey/GxEPD2_213_GDEY0213B74.h")
+#include "gdey/GxEPD2_213_GDEY0213B74.h"
+#endif
+#if __has_include("epd/GxEPD2_260.h")
+#include "epd/GxEPD2_260.h"
+#endif
+#if __has_include("epd/GxEPD2_260_M01.h")
+#include "epd/GxEPD2_260_M01.h"
+#endif
+#if __has_include("epd/GxEPD2_266_BN.h")
+#include "epd/GxEPD2_266_BN.h"
+#endif
+#if __has_include("gdey/GxEPD2_266_GDEY0266T90.h")
+#include "gdey/GxEPD2_266_GDEY0266T90.h"
+#endif
+#if __has_include("epd/GxEPD2_290.h")
+#include "epd/GxEPD2_290.h"
+#endif
+#if __has_include("epd/GxEPD2_290_T5.h")
+#include "epd/GxEPD2_290_T5.h"
+#endif
+#if __has_include("epd/GxEPD2_290_T5D.h")
+#include "epd/GxEPD2_290_T5D.h"
+#endif
+#if __has_include("epd/GxEPD2_290_I6FD.h")
+#include "epd/GxEPD2_290_I6FD.h"
+#endif
+#if __has_include("epd/GxEPD2_290_M06.h")
+#include "epd/GxEPD2_290_M06.h"
+#endif
+#if __has_include("epd/GxEPD2_290_T94.h")
+#include "epd/GxEPD2_290_T94.h"
+#endif
+#if __has_include("gdey/GxEPD2_290_GDEY029T94.h")
+#include "gdey/GxEPD2_290_GDEY029T94.h"
+#endif
+#if __has_include("epd/GxEPD2_290_T94_V2.h")
+#include "epd/GxEPD2_290_T94_V2.h"
+#endif
+#if __has_include("epd/GxEPD2_290_BS.h")
+#include "epd/GxEPD2_290_BS.h"
+#endif
+#if __has_include("gdey/GxEPD2_290_GDEY029T71H.h")
+#include "gdey/GxEPD2_290_GDEY029T71H.h"
+#endif
+#if __has_include("epd/GxEPD2_270.h")
+#include "epd/GxEPD2_270.h"
+#endif
+#if __has_include("gdey/GxEPD2_270_GDEY027T91.h")
+#include "gdey/GxEPD2_270_GDEY027T91.h"
+#endif
+#if __has_include("gdeq/GxEPD2_310_GDEQ031T10.h")
+#include "gdeq/GxEPD2_310_GDEQ031T10.h"
+#endif
+#if __has_include("epd/GxEPD2_371.h")
+#include "epd/GxEPD2_371.h"
+#endif
+#if __has_include("epd/GxEPD2_370_TC1.h")
+#include "epd/GxEPD2_370_TC1.h"
+#endif
+#if __has_include("epd/GxEPD2_420.h")
+#include "epd/GxEPD2_420.h"
+#endif
+#if __has_include("epd/GxEPD2_420_M01.h")
+#include "epd/GxEPD2_420_M01.h"
+#endif
+#if __has_include("gdey/GxEPD2_420_GDEY042T81.h")
+#include "gdey/GxEPD2_420_GDEY042T81.h"
+#endif
+#if __has_include("other/GxEPD2_420_GYE042A87.h")
+#include "other/GxEPD2_420_GYE042A87.h"
+#endif
+#if __has_include("other/GxEPD2_420_SE0420NQ04.h")
+#include "other/GxEPD2_420_SE0420NQ04.h"
+#endif
+#if __has_include("gdeq/GxEPD2_426_GDEQ0426T82.h")
+#include "gdeq/GxEPD2_426_GDEQ0426T82.h"
+#endif
+#if __has_include("gdey/GxEPD2_579_GDEY0579T93.h")
+#include "gdey/GxEPD2_579_GDEY0579T93.h"
+#endif
+#if __has_include("epd/GxEPD2_583.h")
+#include "epd/GxEPD2_583.h"
+#endif
+#if __has_include("epd/GxEPD2_583_T8.h")
+#include "epd/GxEPD2_583_T8.h"
+#endif
+#if __has_include("gdeq/GxEPD2_583_GDEQ0583T31.h")
+#include "gdeq/GxEPD2_583_GDEQ0583T31.h"
+#endif
+#if __has_include("epd/GxEPD2_750.h")
+#include "epd/GxEPD2_750.h"
+#endif
+#if __has_include("epd/GxEPD2_750_T7.h")
+#include "epd/GxEPD2_750_T7.h"
+#endif
+#if __has_include("gdey/GxEPD2_750_GDEY075T7.h")
+#include "gdey/GxEPD2_750_GDEY075T7.h"
+#endif
+#if __has_include("gdem/GxEPD2_1020_GDEM102T91.h")
+#include "gdem/GxEPD2_1020_GDEM102T91.h"
+#endif
+#if __has_include("gdem/GxEPD2_1085_GDEM1085T51.h")
+#include "gdem/GxEPD2_1085_GDEM1085T51.h"
+#endif
+#if __has_include("epd/GxEPD2_1160_T91.h")
+#include "epd/GxEPD2_1160_T91.h"
+#endif
+#if __has_include("gdem/GxEPD2_1330_GDEM133T91.h")
+#include "gdem/GxEPD2_1330_GDEM133T91.h"
+#endif
+#if __has_include("epd/GxEPD2_1248.h")
+#include "epd/GxEPD2_1248.h"
+#endif
+#if __has_include("it8951/GxEPD2_it60.h")
+#include "it8951/GxEPD2_it60.h"
+#endif
+#if __has_include("it8951/GxEPD2_it60_1448x1072.h")
+#include "it8951/GxEPD2_it60_1448x1072.h"
+#endif
+#if __has_include("it8951/GxEPD2_it78_1872x1404.h")
+#include "it8951/GxEPD2_it78_1872x1404.h"
+#endif
+#if __has_include("it8951/GxEPD2_it103_1872x1404.h")
+#include "it8951/GxEPD2_it103_1872x1404.h"
+#endif
+
+template<typename GxEPD2_Type, const uint16_t page_height>
+class GxEPD2_BW : public GxEPD2_GFX_BASE_CLASS
+{
+  public:
+    GxEPD2_Type epd2;
+#ifdef ENABLE_SCREENSHOT
+    // Expose framebuffer for screenshot capture.
+    // This file is a patched copy kept in lib/GxEPD2-patch/src/ and tracked by git.
+    const uint8_t* getBuffer() { return _buffer; }
+    uint16_t getBufferSize() { return sizeof(_buffer); }
+#endif
+#if ENABLE_GxEPD2_GFX
+    GxEPD2_BW(GxEPD2_Type epd2_instance) : GxEPD2_GFX_BASE_CLASS(epd2, GxEPD2_Type::WIDTH_VISIBLE, GxEPD2_Type::HEIGHT), epd2(epd2_instance)
+#else
+    GxEPD2_BW(GxEPD2_Type epd2_instance) : GxEPD2_GFX_BASE_CLASS(GxEPD2_Type::WIDTH_VISIBLE, GxEPD2_Type::HEIGHT), epd2(epd2_instance)
+#endif
+    {
+      _page_height = page_height;
+      _pages = (HEIGHT / _page_height) + ((HEIGHT % _page_height) > 0);
+      _reverse = (epd2_instance.panel == GxEPD2::GDE0213B1);
+      _mirror = false;
+      _using_partial_mode = false;
+      _current_page = 0;
+      setFullWindow();
+    }
+
+    uint16_t pages()
+    {
+      return _pages;
+    }
+
+    uint16_t pageHeight()
+    {
+      return _page_height;
+    }
+
+    bool mirror(bool m)
+    {
+      _swap_ (_mirror, m);
+      return m;
+    }
+
+    void drawPixel(int16_t x, int16_t y, uint16_t color)
+    {
+      if ((x < 0) || (x >= width()) || (y < 0) || (y >= height())) return;
+      if (_mirror) x = width() - x - 1;
+      // check rotation, move pixel around if necessary
+      switch (getRotation())
+      {
+        case 1:
+          _swap_(x, y);
+          x = WIDTH - x - 1;
+          break;
+        case 2:
+          x = WIDTH - x - 1;
+          y = HEIGHT - y - 1;
+          break;
+        case 3:
+          _swap_(x, y);
+          y = HEIGHT - y - 1;
+          break;
+      }
+      // transpose partial window to 0,0
+      x -= _pw_x;
+      if (!_reverse) y -= _pw_y;
+      else y = HEIGHT - _pw_y - y - 1;
+      // clip to (partial) window
+      if ((x < 0) || (x >= int16_t(_pw_w)) || (y < 0) || (y >= int16_t(_pw_h))) return;
+      // adjust for current page
+      y -= _current_page * _page_height;
+      // check if in current page
+      if ((y < 0) || (y >= int16_t(_page_height))) return;
+      uint16_t i = x / 8 + y * (_pw_w / 8);
+      if (color)
+        _buffer[i] = (_buffer[i] | (1 << (7 - x % 8)));
+      else
+        _buffer[i] = (_buffer[i] & (0xFF ^ (1 << (7 - x % 8))));
+    }
+
+    void init(uint32_t serial_diag_bitrate = 0) // = 0 : disabled
+    {
+      epd2.init(serial_diag_bitrate);
+      _using_partial_mode = false;
+      _current_page = 0;
+      setFullWindow();
+    }
+
+    // init method with additional parameters:
+    // initial false for re-init after processor deep sleep wake up, if display power supply was kept
+    // this can be used to avoid the repeated initial full refresh on displays with fast partial update
+    // NOTE: garbage will result on fast partial update displays, if initial full update is omitted after power loss
+    // reset_duration = 10 is default; a value of 2 may help with "clever" reset circuit of newer boards from Waveshare
+    // pulldown_rst_mode true for alternate RST handling to avoid feeding 5V through RST pin
+    void init(uint32_t serial_diag_bitrate, bool initial, uint16_t reset_duration = 10, bool pulldown_rst_mode = false)
+    {
+      epd2.init(serial_diag_bitrate, initial, reset_duration, pulldown_rst_mode);
+      _using_partial_mode = false;
+      _current_page = 0;
+      setFullWindow();
+    }
+
+    // init method with additional parameters:
+    // SPIClass& spi: either SPI or alternate HW SPI channel
+    // SPISettings spi_settings: e.g. for higher SPI speed selection
+    void init(uint32_t serial_diag_bitrate, bool initial, uint16_t reset_duration, bool pulldown_rst_mode, SPIClass& spi, SPISettings spi_settings)
+    {
+      epd2.selectSPI(spi, spi_settings);
+      epd2.init(serial_diag_bitrate, initial, reset_duration, pulldown_rst_mode);
+      _using_partial_mode = false;
+      _current_page = 0;
+      setFullWindow();
+    }
+
+    // release SPI and control pins
+    void end()
+    {
+      epd2.end();
+    }
+
+    void fillScreen(uint16_t color) // 0x0 black, >0x0 white, to buffer
+    {
+      uint8_t data = (color == GxEPD_BLACK) ? 0x00 : 0xFF;
+      for (uint16_t x = 0; x < sizeof(_buffer); x++)
+      {
+        _buffer[x] = data;
+      }
+    }
+
+    // display buffer content to screen, useful for full screen buffer
+    void display(bool partial_update_mode = false)
+    {
+      if (partial_update_mode) epd2.writeImage(_buffer, 0, 0, GxEPD2_Type::WIDTH, _page_height);
+      else epd2.writeImageForFullRefresh(_buffer, 0, 0, GxEPD2_Type::WIDTH, _page_height);
+      epd2.refresh(partial_update_mode);
+      if (epd2.hasFastPartialUpdate)
+      {
+        epd2.writeImageAgain(_buffer, 0, 0, GxEPD2_Type::WIDTH, _page_height);
+      }
+      if (!partial_update_mode) epd2.powerOff();
+    }
+
+    // display part of buffer content to screen, useful for full screen buffer
+    // displayWindow, use parameters according to actual rotation.
+    // x and w should be multiple of 8, for rotation 0 or 2,
+    // y and h should be multiple of 8, for rotation 1 or 3,
+    // else window is increased as needed,
+    // this is an addressing limitation of the e-paper controllers
+    void displayWindow(uint16_t x, uint16_t y, uint16_t w, uint16_t h)
+    {
+      x = gx_uint16_min(x, width());
+      y = gx_uint16_min(y, height());
+      w = gx_uint16_min(w, width() - x);
+      h = gx_uint16_min(h, height() - y);
+      _rotate(x, y, w, h);
+      uint16_t y_part = _reverse ? HEIGHT - h - y : y;
+      epd2.writeImagePart(_buffer, x, y_part, GxEPD2_Type::WIDTH, _page_height, x, y_part, w, h);
+      epd2.refresh(x, y_part, w, h);
+      if (epd2.hasFastPartialUpdate)
+      {
+        epd2.writeImagePartAgain(_buffer, x, y_part, GxEPD2_Type::WIDTH, _page_height, x, y_part, w, h);
+      }
+    }
+
+    void setFullWindow()
+    {
+      _using_partial_mode = false;
+      _pw_x = 0;
+      _pw_y = 0;
+      _pw_w = GxEPD2_Type::WIDTH;
+      _pw_h = HEIGHT;
+    }
+
+    // setPartialWindow, use parameters according to actual rotation.
+    // x and w should be multiple of 8, for rotation 0 or 2,
+    // y and h should be multiple of 8, for rotation 1 or 3,
+    // else window is increased as needed,
+    // this is an addressing limitation of the e-paper controllers
+    void setPartialWindow(uint16_t x, uint16_t y, uint16_t w, uint16_t h)
+    {
+      _pw_x = gx_uint16_min(x, width());
+      _pw_y = gx_uint16_min(y, height());
+      _pw_w = gx_uint16_min(w, width() - _pw_x);
+      _pw_h = gx_uint16_min(h, height() - _pw_y);
+      _rotate(_pw_x, _pw_y, _pw_w, _pw_h);
+      _using_partial_mode = true;
+      // make _pw_x, _pw_w multiple of 8
+      _pw_w += _pw_x % 8;
+      if (_pw_w % 8 > 0) _pw_w += 8 - _pw_w % 8;
+      _pw_x -= _pw_x % 8;
+      if (_reverse) _pw_y = HEIGHT - _pw_h - _pw_y;
+    }
+
+    void firstPage()
+    {
+      fillScreen(GxEPD_WHITE);
+      _current_page = 0;
+      _second_phase = false;
+    }
+
+    bool nextPage()
+    {
+      if (1 == _pages)
+      {
+        if (_using_partial_mode)
+        {
+          epd2.writeImage(_buffer, _pw_x, _pw_y, _pw_w, _pw_h);
+          epd2.refresh(_pw_x, _pw_y, _pw_w, _pw_h);
+          if (epd2.hasFastPartialUpdate)
+          {
+            epd2.writeImageAgain(_buffer, _pw_x, _pw_y, _pw_w, _pw_h);
+            //epd2.refresh(_pw_x, _pw_y, _pw_w, _pw_h); // not needed
+          }
+        }
+        else // full update
+        {
+          epd2.writeImageForFullRefresh(_buffer, 0, 0, GxEPD2_Type::WIDTH, HEIGHT);
+          epd2.refresh(false);
+          if (epd2.hasFastPartialUpdate)
+          {
+            epd2.writeImageAgain(_buffer, 0, 0, GxEPD2_Type::WIDTH, HEIGHT);
+            //epd2.refresh(true); // not needed
+          }
+          epd2.powerOff();
+        }
+        return false;
+      }
+      uint16_t page_ys = _current_page * _page_height;
+      if (_using_partial_mode)
+      {
+        //Serial.print("  nextPage("); Serial.print(_pw_x); Serial.print(", "); Serial.print(_pw_y); Serial.print(", ");
+        //Serial.print(_pw_w); Serial.print(", "); Serial.print(_pw_h); Serial.print(") P"); Serial.println(_current_page);
+        uint16_t page_ye = _current_page < int16_t(_pages - 1) ? page_ys + _page_height : HEIGHT;
+        uint16_t dest_ys = _pw_y + page_ys; // transposed
+        uint16_t dest_ye = gx_uint16_min(_pw_y + _pw_h, _pw_y + page_ye);
+        if (dest_ye > dest_ys)
+        {
+          //Serial.print("writeImage("); Serial.print(_pw_x); Serial.print(", "); Serial.print(dest_ys); Serial.print(", ");
+          //Serial.print(_pw_w); Serial.print(", "); Serial.print(dest_ye - dest_ys); Serial.println(")");
+          if (!_second_phase) epd2.writeImage(_buffer, _pw_x, dest_ys, _pw_w, dest_ye - dest_ys);
+          else epd2.writeImageAgain(_buffer, _pw_x, dest_ys, _pw_w, dest_ye - dest_ys);
+        }
+        else
+        {
+          //Serial.print("writeImage("); Serial.print(_pw_x); Serial.print(", "); Serial.print(dest_ys); Serial.print(", ");
+          //Serial.print(_pw_w); Serial.print(", "); Serial.print(dest_ye - dest_ys); Serial.print(") skipped ");
+          //Serial.print(dest_ys); Serial.print(".."); Serial.println(dest_ye);
+        }
+        _current_page++;
+        if (_current_page == int16_t(_pages))
+        {
+          _current_page = 0;
+          if (!_second_phase)
+          {
+            epd2.refresh(_pw_x, _pw_y, _pw_w, _pw_h);
+            if (epd2.hasFastPartialUpdate)
+            {
+              _second_phase = true;
+              fillScreen(GxEPD_WHITE);
+              return true;
+            }
+          }
+          return false;
+        }
+        fillScreen(GxEPD_WHITE);
+        return true;
+      }
+      else // full update
+      {
+        if (!_second_phase) epd2.writeImageForFullRefresh(_buffer, 0, page_ys, GxEPD2_Type::WIDTH, gx_uint16_min(_page_height, HEIGHT - page_ys));
+        else epd2.writeImageAgain(_buffer, 0, page_ys, GxEPD2_Type::WIDTH, gx_uint16_min(_page_height, HEIGHT - page_ys));
+        _current_page++;
+        if (_current_page == int16_t(_pages))
+        {
+          _current_page = 0;
+          if (epd2.hasFastPartialUpdate)
+          {
+            if (!_second_phase)
+            {
+              epd2.refresh(false); // full update after first phase
+              _second_phase = true;
+              fillScreen(GxEPD_WHITE);
+              return true;
+            }
+            //else epd2.refresh(true); // partial update after second phase
+          } else epd2.refresh(false); // full update after only phase
+          epd2.powerOff();
+          return false;
+        }
+        fillScreen(GxEPD_WHITE);
+        return true;
+      }
+    }
+
+    // GxEPD style paged drawing; drawCallback() is called as many times as needed
+    void drawPaged(void (*drawCallback)(const void*), const void* pv)
+    {
+      if (1 == _pages)
+      {
+        fillScreen(GxEPD_WHITE);
+        drawCallback(pv);
+        if (_using_partial_mode)
+        {
+          epd2.writeImage(_buffer, _pw_x, _pw_y, _pw_w, _pw_h);
+          epd2.refresh(_pw_x, _pw_y, _pw_w, _pw_h);
+          if (epd2.hasFastPartialUpdate)
+          {
+            epd2.writeImageAgain(_buffer, _pw_x, _pw_y, _pw_w, _pw_h);
+            //epd2.refresh(_pw_x, _pw_y, _pw_w, _pw_h); // not needed
+          }
+        }
+        else // full update
+        {
+          epd2.writeImageForFullRefresh(_buffer, 0, 0, GxEPD2_Type::WIDTH, HEIGHT);
+          epd2.refresh(false);
+          if (epd2.hasFastPartialUpdate)
+          {
+            epd2.writeImageAgain(_buffer, 0, 0, GxEPD2_Type::WIDTH, HEIGHT);
+            //epd2.refresh(true); // not needed
+            epd2.powerOff();
+          }
+        }
+        return;
+      }
+      if (_using_partial_mode)
+      {
+        for (uint16_t phase = 1; phase <= 2; phase++)
+        {
+          for (_current_page = 0; _current_page < _pages; _current_page++)
+          {
+            uint16_t page_ys = _current_page * _page_height;
+            uint16_t page_ye = _current_page < (_pages - 1) ? page_ys + _page_height : HEIGHT;
+            uint16_t dest_ys = _pw_y + page_ys; // transposed
+            uint16_t dest_ye = gx_uint16_min(_pw_y + _pw_h, _pw_y + page_ye);
+            if (dest_ye > dest_ys)
+            {
+              fillScreen(GxEPD_WHITE);
+              drawCallback(pv);
+              if (phase == 1) epd2.writeImage(_buffer, _pw_x, dest_ys, _pw_w, dest_ye - dest_ys);
+              else epd2.writeImageAgain(_buffer, _pw_x, dest_ys, _pw_w, dest_ye - dest_ys);
+            }
+          }
+          epd2.refresh(_pw_x, _pw_y, _pw_w, _pw_h);
+          if (!epd2.hasFastPartialUpdate) break;
+          // else make both controller buffers have equal content
+        }
+      }
+      else // full update
+      {
+        for (_current_page = 0; _current_page < _pages; _current_page++)
+        {
+          uint16_t page_ys = _current_page * _page_height;
+          fillScreen(GxEPD_WHITE);
+          drawCallback(pv);
+          epd2.writeImageForFullRefresh(_buffer, 0, page_ys, GxEPD2_Type::WIDTH, gx_uint16_min(_page_height, HEIGHT - page_ys));
+        }
+        epd2.refresh(false); // full update after first phase
+        if (epd2.hasFastPartialUpdate)
+        {
+          // make both controller buffers have equal content
+          for (_current_page = 0; _current_page < _pages; _current_page++)
+          {
+            uint16_t page_ys = _current_page * _page_height;
+            fillScreen(GxEPD_WHITE);
+            drawCallback(pv);
+            epd2.writeImageAgain(_buffer, 0, page_ys, GxEPD2_Type::WIDTH, gx_uint16_min(_page_height, HEIGHT - page_ys));
+          }
+          //epd2.refresh(true); // partial update after second phase // not needed
+        }
+        epd2.powerOff();
+      }
+      _current_page = 0;
+    }
+
+    void drawInvertedBitmap(int16_t x, int16_t y, const uint8_t bitmap[], int16_t w, int16_t h, uint16_t color)
+    {
+      // taken from Adafruit_GFX.cpp, modified
+      int16_t byteWidth = (w + 7) / 8; // Bitmap scanline pad = whole byte
+      uint8_t byte = 0;
+      for (int16_t j = 0; j < h; j++)
+      {
+        for (int16_t i = 0; i < w; i++ )
+        {
+          if (i & 7) byte <<= 1;
+          else
+          {
+#if defined(__AVR) || defined(ESP8266) || defined(ESP32)
+            byte = pgm_read_byte(&bitmap[j * byteWidth + i / 8]);
+#else
+            byte = bitmap[j * byteWidth + i / 8];
+#endif
+          }
+          if (!(byte & 0x80))
+          {
+            drawPixel(x + i, y + j, color);
+          }
+        }
+      }
+    }
+
+    //  Support for Bitmaps (Sprites) to Controller Buffer and to Screen
+    void clearScreen(uint8_t value = 0xFF) // init controller memory and screen (default white)
+    {
+      epd2.clearScreen(value);
+    }
+    void writeScreenBuffer(uint8_t value = 0xFF) // init controller memory (default white)
+    {
+      epd2.writeScreenBuffer(value);
+    }
+    // write to controller memory, without screen refresh; x and w should be multiple of 8
+    void writeImage(const uint8_t bitmap[], int16_t x, int16_t y, int16_t w, int16_t h, bool invert = false, bool mirror_y = false, bool pgm = false)
+    {
+      epd2.writeImage(bitmap, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void writeImagePart(const uint8_t bitmap[], int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
+                        int16_t x, int16_t y, int16_t w, int16_t h, bool invert = false, bool mirror_y = false, bool pgm = false)
+    {
+      epd2.writeImagePart(bitmap, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void writeImage(const uint8_t* black, const uint8_t* color, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
+    {
+      epd2.writeImage(black, color, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void writeImage(const uint8_t* black, const uint8_t* color, int16_t x, int16_t y, int16_t w, int16_t h)
+    {
+      epd2.writeImage(black, color, x, y, w, h, false, false, false);
+    }
+    void writeImagePart(const uint8_t* black, const uint8_t* color, int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
+                        int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
+    {
+      epd2.writeImagePart(black, color, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void writeImagePart(const uint8_t* black, const uint8_t* color, int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
+                        int16_t x, int16_t y, int16_t w, int16_t h)
+    {
+      epd2.writeImagePart(black, color, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, false, false, false);
+    }
+    // write sprite of native data to controller memory, without screen refresh; x and w should be multiple of 8
+    void writeNative(const uint8_t* data1, const uint8_t* data2, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
+    {
+      epd2.writeNative(data1, data2, x, y, w, h, invert, mirror_y, pgm);
+    }
+    // write to controller memory, with screen refresh; x and w should be multiple of 8
+    void drawImage(const uint8_t bitmap[], int16_t x, int16_t y, int16_t w, int16_t h, bool invert = false, bool mirror_y = false, bool pgm = false)
+    {
+      epd2.drawImage(bitmap, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void drawImagePart(const uint8_t bitmap[], int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
+                       int16_t x, int16_t y, int16_t w, int16_t h, bool invert = false, bool mirror_y = false, bool pgm = false)
+    {
+      epd2.drawImagePart(bitmap, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void drawImage(const uint8_t* black, const uint8_t* color, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
+    {
+      epd2.drawImage(black, color, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void drawImage(const uint8_t* black, const uint8_t* color, int16_t x, int16_t y, int16_t w, int16_t h)
+    {
+      epd2.drawImage(black, color, x, y, w, h, false, false, false);
+    }
+    void drawImagePart(const uint8_t* black, const uint8_t* color, int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
+                       int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
+    {
+      epd2.drawImagePart(black, color, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void drawImagePart(const uint8_t* black, const uint8_t* color, int16_t x_part, int16_t y_part, int16_t w_bitmap, int16_t h_bitmap,
+                       int16_t x, int16_t y, int16_t w, int16_t h)
+    {
+      epd2.drawImagePart(black, color, x_part, y_part, w_bitmap, h_bitmap, x, y, w, h, false, false, false);
+    }
+    // write sprite of native data to controller memory, with screen refresh; x and w should be multiple of 8
+    void drawNative(const uint8_t* data1, const uint8_t* data2, int16_t x, int16_t y, int16_t w, int16_t h, bool invert, bool mirror_y, bool pgm)
+    {
+      epd2.drawNative(data1, data2, x, y, w, h, invert, mirror_y, pgm);
+    }
+    void refresh(bool partial_update_mode = false) // screen refresh from controller memory to full screen
+    {
+      epd2.refresh(partial_update_mode);
+      if (!partial_update_mode) epd2.powerOff();
+    }
+    void refresh(int16_t x, int16_t y, int16_t w, int16_t h) // screen refresh from controller memory, partial screen
+    {
+      epd2.refresh(x, y, w, h);
+    }
+    // turns off generation of panel driving voltages, avoids screen fading over time
+    void powerOff()
+    {
+      epd2.powerOff();
+    }
+    // turns powerOff() and sets controller to deep sleep for minimum power use, ONLY if wakeable by RST (rst >= 0)
+    void hibernate()
+    {
+      epd2.hibernate();
+    }
+  private:
+    template <typename T> static inline void
+    _swap_(T & a, T & b)
+    {
+      T t = a;
+      a = b;
+      b = t;
+    };
+    static inline uint16_t gx_uint16_min(uint16_t a, uint16_t b)
+    {
+      return (a < b ? a : b);
+    };
+    static inline uint16_t gx_uint16_max(uint16_t a, uint16_t b)
+    {
+      return (a > b ? a : b);
+    };
+    void _rotate(uint16_t& x, uint16_t& y, uint16_t& w, uint16_t& h)
+    {
+      switch (getRotation())
+      {
+        case 1:
+          _swap_(x, y);
+          _swap_(w, h);
+          x = WIDTH - x - w;
+          break;
+        case 2:
+          x = WIDTH - x - w;
+          y = HEIGHT - y - h;
+          break;
+        case 3:
+          _swap_(x, y);
+          _swap_(w, h);
+          y = HEIGHT - y - h;
+          break;
+      }
+    }
+  private:
+    uint8_t _buffer[(GxEPD2_Type::WIDTH / 8) * page_height];
+    bool _using_partial_mode, _second_phase, _mirror, _reverse;
+    uint16_t _width_bytes, _pixel_bytes;
+    int16_t _current_page;
+    uint16_t _pages, _page_height;
+    uint16_t _pw_x, _pw_y, _pw_w, _pw_h;
+};
+
+#endif

src/helpers/ui/DisplayDriver.h

@@ -247,4 +247,12 @@ public:
   virtual void setDisplayRotation(uint8_t rot) { }  // 0-3, no-op for fixed-orientation displays
   virtual void setFullRefreshInterval(uint8_t n) { }  // e-ink: do full refresh every n partial refreshes (0=never)
   virtual void endFrame() = 0;
+
+#ifdef ENABLE_SCREENSHOT
+  // Screenshot support — return raw framebuffer and its size in bytes.
+  // 0=OLED (page-based, column-major), 1=e-ink (row-major, MSB-first, 1=white/0=black).
+  virtual const uint8_t* getBuffer() { return nullptr; }
+  virtual uint16_t getBufferSize() { return 0; }
+  virtual uint8_t getDisplayType() { return 0; }
+#endif
 };

src/helpers/ui/GxEPDDisplay.h

@@ -5,7 +5,15 @@
 
 #define ENABLE_GxEPD2_GFX 0
 
+// When ENABLE_SCREENSHOT is active, use the patched copy of GxEPD2_BW.h from
+// lib/GxEPD2-patch/src/ that exposes getBuffer()/getBufferSize().  The include
+// guard (_GxEPD2_BW_H_) then prevents the installed library version from
+// being compiled again.  Non-screenshot builds use the installed library as-is.
+#ifdef ENABLE_SCREENSHOT
+#include "../../../lib/GxEPD2-patch/src/GxEPD2_BW.h"
+#else
 #include <GxEPD2_BW.h>
+#endif
 #include <GxEPD2_3C.h>
 #include <GxEPD2_4C.h>
 #include <GxEPD2_7C.h>
@@ -70,6 +78,12 @@ public:
     display(GxEPD2_150_BN(DISP_CS, DISP_DC, DISP_RST, DISP_BUSY)) {}
 #endif
 
+#ifdef ENABLE_SCREENSHOT
+  const uint8_t* getBuffer() override { return display.getBuffer(); }
+  uint16_t getBufferSize() override { return display.getBufferSize(); }
+  uint8_t getDisplayType() override { return 1; }  // 1 = e-ink
+#endif
+
   // Line height and approx. char width for each font size:
   //   1 = FreeSans9pt      (lineH=16, charW≈9)
   //   2 = FreeSansBold12pt (lineH=20, charW≈12)

src/helpers/ui/SH1106Display.h

@@ -60,7 +60,8 @@ public:
   void endFrame() override;
   
 #ifdef ENABLE_SCREENSHOT
-  // Screenshot support
+  const uint8_t* getBuffer() override { return display.getBuffer(); }
-  uint8_t* getBuffer() { return display.getBuffer(); }
+  uint16_t getBufferSize() override { return (uint16_t)((width() * height()) / 8); }
+  uint8_t getDisplayType() override { return 0; }
 #endif
 };

src/helpers/ui/SSD1306Display.h

@@ -47,7 +47,8 @@ public:
   void endFrame() override;
   
 #ifdef ENABLE_SCREENSHOT
-  // Screenshot support
+  const uint8_t* getBuffer() override { return display.getBuffer(); }
-  uint8_t* getBuffer() { return display.getBuffer(); }
+  uint16_t getBufferSize() override { return (uint16_t)((width() * height()) / 8); }
+  uint8_t getDisplayType() override { return 0; }
 #endif
 };

tools/screenshot.py

@@ -1,6 +1,6 @@
 #!/usr/bin/env python3
 """
-Screenshot tool for Wio L1 Tracker Pro with SH1106 display.
+Screenshot tool for Wio L1 Tracker Pro (OLED SH1106 and e-ink GxEPD2).
 Connects via USB serial using mesh companion protocol, captures framebuffer, saves as PNG.
 
 Usage:
@@ -26,14 +26,19 @@ FRAME_START_IN = 0x3E  # '>' - used when receiving FROM device
 CMD_GET_SCREENSHOT = 66
 RESP_CODE_SCREENSHOT = 29
 RESP_CODE_ERR = 1
-DISPLAY_WIDTH = 128
+
-DISPLAY_HEIGHT = 64
+# display_type values (byte [5] in response frame)
-BUFFER_SIZE = (DISPLAY_WIDTH * DISPLAY_HEIGHT) // 8  # 1024 bytes
+DISPLAY_TYPE_OLED = 0   # page-based, column-major (SH1106/SSD1306)
+DISPLAY_TYPE_EINK = 1   # row-major, MSB-first, 1=white/0=black (GxEPD2)
+
+# E-ink panel constants for GxEPD2_213_B74 / GxEPD2_213_BN
+EINK_PHYS_WIDTH = 128   # full hardware width including invisible columns
+EINK_VISIBLE_W  = 122   # WIDTH_VISIBLE — columns actually shown on panel
 
 
 def parse_args():
     parser = argparse.ArgumentParser(
-        description="Capture screenshots from Wio L1 Tracker Pro with SH1106 display"
+        description="Capture screenshots from Wio L1 Tracker Pro (OLED or e-ink)"
     )
     parser.add_argument(
         "--port", "-p", help="Serial port to use (default: auto-detect)"
@@ -101,11 +106,16 @@ def send_command(ser, command, data=b""):
 
 
 def receive_screenshot(ser, timeout=5):
-    """Receive screenshot data (may be split across multiple frames)"""
+    """Receive screenshot data (may be split across multiple frames).
+
+    Frame format: RESP_CODE_SCREENSHOT, width, height, chunk_idx,
+                  total_chunks, display_type, [chunk_data...]
+    """
     start_time = time.time()
     buffer_data = bytearray()
     width = None
     height = None
+    display_type = None
     total_chunks = None
     received_chunks = 0
 
@@ -114,7 +124,7 @@ def receive_screenshot(ser, timeout=5):
         if frame is None:
             continue
 
-        if len(frame) < 5:
+        if len(frame) < 6:
             print(f"Error: Frame too short: {len(frame)} bytes")
             return None
 
@@ -125,11 +135,13 @@ def receive_screenshot(ser, timeout=5):
             h            = frame[2]
             chunk_idx    = frame[3]
             num_chunks   = frame[4]
-            chunk_data = frame[5:]
+            disp_type    = frame[5]
+            chunk_data   = frame[6:]
 
             if chunk_idx == 0:
                 width         = w
                 height        = h
+                display_type  = disp_type
                 total_chunks  = num_chunks
                 buffer_data   = bytearray()
                 received_chunks = 0
@@ -146,14 +158,7 @@ def receive_screenshot(ser, timeout=5):
             received_chunks += 1
 
             if received_chunks >= total_chunks:
-                expected_size = (width * height) // 8
+                return bytes(buffer_data), width, height, display_type
-                if len(buffer_data) == expected_size:
-                    return bytes(buffer_data), width, height
-                else:
-                    print(
-                        f"Error: Expected {expected_size} bytes, got {len(buffer_data)}"
-                    )
-                    return None
 
         elif resp_code == RESP_CODE_ERR:
             print("Error: Device returned error")
@@ -168,13 +173,13 @@ def receive_screenshot(ser, timeout=5):
     return None
 
 
-def buffer_to_image(buffer, width, height, scale=1):
+def oled_buffer_to_image(buffer, width, height):
-    """Convert SH1106/SH1106 framebuffer to PIL Image with white text on black background and black frame"""
+    """Decode SH1106/SSD1306 framebuffer (page-based, column-major).
+    Each byte covers 8 vertical pixels; bit 0 = top pixel of the byte.
+    """
     image = Image.new("1", (width, height), 0)
     pixels = image.load()
-
     bytes_per_page = width
-
     for page in range(0, height, 8):
         page_start = (page // 8) * bytes_per_page
         for col in range(width):
@@ -183,22 +188,61 @@ def buffer_to_image(buffer, width, height, scale=1):
                 byte_val = buffer[byte_idx]
                 for bit in range(8):
                     if page + bit < height:
-                        pixel_value = 1 if (byte_val & (1 << bit)) else 0
+                        pixels[col, page + bit] = 1 if (byte_val & (1 << bit)) else 0
-                        pixels[col, page + bit] = pixel_value
+    return image.convert("RGB")
 
-    # Convert to RGB: white text on black background (no inversion)
-    image_rgb = image.convert("RGB")
 
-    # Add 3-pixel black frame around the image
+def eink_buffer_to_image(buffer, log_width, log_height):
+    """Decode GxEPD2 framebuffer for GxEPD2_213_B74 with DISPLAY_ROTATION=1 (landscape).
+
+    Physical panel: PHYS_WIDTH=128, HEIGHT=250.
+    Buffer layout: row-major, stride=PHYS_WIDTH/8=16 bytes, MSB-first.
+      byte index = phys_y * 16 + phys_x // 8
+      bit        = 7 - phys_x % 8
+      value 1    = white (paper), 0 = black (ink)
+
+    With setRotation(1), GxEPD2 maps logical (lx, ly) to physical:
+      phys_x = PHYS_WIDTH - 1 - ly  (= 127 - ly)
+      phys_y = lx
+
+    Visible logical height = EINK_VISIBLE_W = 122 (PHYS_WIDTH_VISIBLE).
+    We trim to visible_h rows so the 6 invisible physical columns don't appear.
+    """
+    phys_stride = EINK_PHYS_WIDTH // 8          # 16 bytes per physical row
+    visible_h   = min(log_height, EINK_VISIBLE_W)  # trim to 122
+
+    image = Image.new("RGB", (log_width, visible_h), (255, 255, 255))
+    pixels = image.load()
+
+    for ly in range(visible_h):
+        phys_x = EINK_PHYS_WIDTH - 1 - ly        # 127 - ly
+        for lx in range(log_width):
+            phys_y    = lx
+            byte_idx  = phys_y * phys_stride + phys_x // 8
+            bit       = 7 - phys_x % 8
+            if byte_idx < len(buffer):
+                raw = (buffer[byte_idx] >> bit) & 1
+                # 1=white (paper), 0=black (ink)
+                color = (255, 255, 255) if raw else (0, 0, 0)
+                pixels[lx, ly] = color
+
+    return image
+
+
+def buffer_to_image(buffer, width, height, display_type, scale=1):
+    """Convert framebuffer to PIL Image with a 3-pixel black frame."""
+    if display_type == DISPLAY_TYPE_EINK:
+        image_rgb = eink_buffer_to_image(buffer, width, height)
+    else:
+        image_rgb = oled_buffer_to_image(buffer, width, height)
+
+    # Add 3-pixel black frame
     FRAME_WIDTH = 3
-    new_width = width + FRAME_WIDTH * 2
+    fw = image_rgb.width  + FRAME_WIDTH * 2
-    new_height = height + FRAME_WIDTH * 2
+    fh = image_rgb.height + FRAME_WIDTH * 2
-    final_image = Image.new("RGB", (new_width, new_height), (0, 0, 0))
+    final_image = Image.new("RGB", (fw, fh), (0, 0, 0))
-
-    # Paste the display content in the center
     final_image.paste(image_rgb, (FRAME_WIDTH, FRAME_WIDTH))
 
-    # Upscale if requested
     if scale > 1:
         final_image = final_image.resize(
             (final_image.width * scale, final_image.height * scale),
@@ -240,7 +284,7 @@ def main():
         sys.exit(1)
 
     try:
-        print("Screenshot Tool for Wio L1 Tracker Pro")
+        print("Screenshot Tool for Wio L1 Tracker Pro (OLED + e-ink)")
         print("Press 'S' to capture screenshot, 'Q' to quit\n")
 
         while True:
@@ -263,14 +307,15 @@ def main():
 
                 result = receive_screenshot(ser)
                 if result:
-                    buffer_data, width, height = result
+                    buffer_data, width, height, display_type = result
+                    type_str = "e-ink" if display_type == DISPLAY_TYPE_EINK else "OLED"
                     print(
-                        f"Received framebuffer: {width}x{height}, {len(buffer_data)} bytes"
+                        f"Received framebuffer: {width}x{height} {type_str}, {len(buffer_data)} bytes"
                     )
 
                     try:
                         image = buffer_to_image(
-                            buffer_data, width, height, scale=args.scale
+                            buffer_data, width, height, display_type, scale=args.scale
                         )
                         filename = generate_filename()
                         image.save(filename)

variants/wio-tracker-l1-eink/platformio.ini

@@ -9,6 +9,7 @@ build_flags = ${nrf52_base.build_flags}
   -I lib/nrf52/s140_nrf52_7.3.0_API/include/nrf52
   -I variants/wio-tracker-l1
   -I examples/companion_radio/ui-new
+  -I lib/GxEPD2-patch/src
   -D WIO_TRACKER_L1
   -D WIO_TRACKER_L1_EINK
   -D USE_SX1262
@@ -66,3 +67,10 @@ extends = WioTrackerL1Eink
 build_flags = ${WioTrackerL1Eink.build_flags}
   -D DUAL_SERIAL=1
 extra_scripts = post:create-uf2.py
+
+; Dual BLE+USB with screenshot support (development/debug)
+[env:WioTrackerL1Eink_companion_dual_dev]
+extends = WioTrackerL1Eink
+build_flags = ${WioTrackerL1Eink.build_flags}
+  -D DUAL_SERIAL=1
+  -D ENABLE_SCREENSHOT

variants/wio-tracker-l1/platformio.ini

@@ -152,3 +152,10 @@ extends = WioTrackerL1CompanionDual
 build_flags = ${WioTrackerL1CompanionDual.build_flags}
   -D UI_HAS_JOYSTICK_UPDOWN=1
 extra_scripts = post:create-uf2.py
+
+[env:WioTrackerL1_companion_dual_dev]
+extends = WioTrackerL1CompanionDual
+build_flags = ${WioTrackerL1CompanionDual.build_flags}
+  -D UI_HAS_JOYSTICK_UPDOWN=1
+  -D DUAL_SERIAL=1
+  -D ENABLE_SCREENSHOT