Files
MeshCore-Solo/tools
Jakub a84cee0f57 fix(screenshot): widen header to uint16, sanity-check buffer, fix ERR path
Protocol header grows from 7 to 11 bytes: display_type, rotation, then
uint16 LE width / height / chunk_idx / total_chunks. Removes silent
truncation on panels >255 px (e.g. future 4.2" 400x300 e-ink).

Decoder now:
- checks RESP_CODE_ERR before length so error frames don't surface as
  "Frame too short"; logs the error code byte
- validates received buffer size against expected (OLED: w*h/8; e-ink:
  ceil(min(w,h)/8) * max(w,h)) so truncated transfers fail loudly
- initializes disp_rotation in outer scope and detects missed chunk 0

Co-Authored-By: Claude Opus 4.7 <noreply@anthropic.com>
2026-05-28 21:03:05 +02:00
..

Display Screenshot Tool

⚠️ Note: The screenshot feature requires the ENABLE_SCREENSHOT build flag to be enabled. Add -D ENABLE_SCREENSHOT to your PlatformIO build flags, then recompile and flash the firmware.

The firmware supports capturing the current display contents and transmitting it over USB serial. This is useful for debugging, remote monitoring, or creating documentation.

Important: When the device is connected to the companion app, the USB serial port is not available for communication. To use the screenshot tool, ensure the device is not connected to the companion app.

Usage:

  1. Build and flash firmware with -D ENABLE_SCREENSHOT build flag enabled

Example for the OLED dual firmware:

PLATFORMIO_BUILD_FLAGS="-D ENABLE_SCREENSHOT" pio run -e WioTrackerL1_companion_dual -t upload
  1. Connect the device to your computer via USB (ensure no companion app connection)

  2. Install dependencies and run the screenshot tool. To manage python and python dependencies, use uv: https://docs.astral.sh/uv/

    cd tools
    uv run tools/screenshot.py
    

    Options:

    • --port PORT — Serial port to use (default: auto-detect)
    • --scale SCALE — Upscale factor for the output image (1=no upscale, 2=2x, 3=3x, 4=4x, etc.; default: 1)
  3. In the tool's interactive menu, press S to capture a screenshot

  4. The tool will save the screenshot as a PNG file in tools/pngs/ with a timestamp-based filename

How it works:

  • The tool sends the CMD_GET_SCREENSHOT command (66) to the device
  • The device responds with RESP_CODE_SCREENSHOT (29) containing the framebuffer data
  • The framebuffer is transmitted in chunks (128×64 display = 1024 bytes, split across multiple frames)
  • The tool reassembles the chunks and converts them to a PNG image