Firmware (7-byte header):
Byte 7 = display->screenshotRotation() — GxEPD2/GFX rotation value (0-3).
DisplayDriver::screenshotRotation() defaults to 0 (OLED).
GxEPDDisplay::screenshotRotation() returns display.getRotation(), the
live GxEPD2 value (reflects runtime setDisplayRotation() calls, not just
the compile-time DISPLAY_ROTATION macro).
Python decoder:
- Parse 7-byte header; pass rotation to eink_buffer_to_image().
- Implement all four GxEPD2 drawPixel coordinate transforms:
rot 0: phys_x=lx, phys_y=ly
rot 1: phys_x=vis_w-1-ly, phys_y=lx
rot 2: phys_x=vis_w-1-lx, phys_y=vis_h-1-ly (180° flip)
rot 3: phys_x=ly, phys_y=vis_h-1-lx
- vis_w/vis_h derived from log dimensions + rotation parity (no constants).
- Print rot= in the status line so the user sees which rotation was used.
This fixes the 180° rotated image seen with rotation=2 (portrait inverted)
without hardcoding a flip — correct for any rotation value.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
The previous decoder always applied the rotation=1 (landscape) transform,
which caused three visible artefacts on a portrait (rotation=0) device:
- Content rotated 90° — wrong phys_x/phys_y mapping
- Content doubled/skewed — stride = buffer/log_width = 4000/122 = 32
instead of buffer/HEIGHT = 4000/250 = 16
Fix: infer rotation from aspect ratio (portrait: log_height > log_width).
portrait → direct mapping: phys_x=lx, phys_y=ly
landscape → rotation-1 map: phys_x=log_height-1-ly, phys_y=lx
Derive phys_stride from buffer_size // max(log_w, log_h) — the physical
HEIGHT is always the longer axis regardless of rotation, giving 16 bytes/row
for GxEPD2_213_B74 in both orientations.
No panel-specific constants remain; works for any GxEPD2 panel/rotation.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
Firmware: add screenshotWidth()/screenshotHeight() virtual pair to
DisplayDriver (default: width()/height()). GxEPDDisplay overrides to
return display.width()/display.height() — the GxEPD2-reported values
that use WIDTH_VISIBLE (e.g. 122 for GxEPD2_213_B74), not the full
physical WIDTH stored in DisplayDriver (128). MyMesh uses these
instead of display->width()/height() for the screenshot header bytes.
Result for GxEPD2_213_B74 + DISPLAY_ROTATION=1:
header was 250×128 → now 250×122 (correct visible canvas)
Python decoder (tools/screenshot.py):
- Remove hardcoded EINK_PHYS_WIDTH=128 / EINK_VISIBLE_W=122 constants.
- Derive phys_stride from buffer_size / log_width (works for any panel).
- Fix phys_x formula: was (EINK_PHYS_WIDTH-1-ly = 127-ly),
now (vis_w-1-ly = log_height-1-ly = 121-ly for 213_B74).
Old formula addressed invisible columns 122-127; new formula correctly
maps logical rows 0..121 to visible physical columns 121..0.
- vis_w = log_height (no hardcoded trim; header now carries correct value).
This also works for square panels (e.g. 128×128 where WIDTH=WIDTH_VISIBLE):
header will carry 128×128, decoder produces a correct 128×128 image.
Co-Authored-By: Claude Sonnet 4.6 <noreply@anthropic.com>
- 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>
- Adds the possibility to capture the device screen and save it as a PNG
image
- Wrap the code behind ENABLE_SCREENSHOT build flag, as per instructions
in README
