From 4b1c8d16f72bb5d8f2eb8a2e8dde35abdd2f2a88 Mon Sep 17 00:00:00 2001 From: hathach Date: Mon, 29 Jun 2026 10:16:25 +0700 Subject: docs: add build-doc tooling and a README for every example Documentation tooling: - Add the `build-doc` skill and `tools/build_doc.py` wrapper for local Sphinx builds (clean / -W / open). - Enable Markdown (MyST) in conf.py and auto-collect examples/{device,host,dual}/*/README.md into a 3-level Examples nav (Examples > Device/Host/Dual > example), noting each page's source location and normalizing headings to a single H1. - Remove the stale `.claude/commands/build-doc.md`; point the AGENTS.md Documentation section at the skill. Example docs: - Add a README.md for every device/host/dual example: what it does, USB interface table, notable tusb_config.h settings, generic CMake + Make build steps, and how to try it. - Fold each *_freertos variant into its base README, noting the FreeRTOS source path and any RTOS-specific behavior. Generated docs/examples/ output is git-ignored. Builds clean with `sphinx-build -W`. Co-Authored-By: Claude Opus 4.8 (1M context) --- examples/device/video_capture/README.md | 48 +++++++++++++++++++++++++++++++++ 1 file changed, 48 insertions(+) create mode 100644 examples/device/video_capture/README.md (limited to 'examples/device/video_capture') diff --git a/examples/device/video_capture/README.md b/examples/device/video_capture/README.md new file mode 100644 index 000000000..9c16cd701 --- /dev/null +++ b/examples/device/video_capture/README.md @@ -0,0 +1,48 @@ +# Video Capture (UVC) + +A USB Video Class (UVC) camera that streams generated color-bar frames. + +## What it does + +- Presents itself as a UVC camera and streams 128x96 video at 10 fps. +- By default generates YUY2 (uncompressed) color-bar frames into a RAM frame buffer; build options select alternatives: `CFG_EXAMPLE_VIDEO_READONLY` streams fixed MJPEG images from flash (or YUY2 with `CFG_EXAMPLE_VIDEO_DISABLE_MJPEG`), and `CFG_EXAMPLE_VIDEO_BUFFERLESS` fills the payload on the fly. +- Uses an isochronous streaming endpoint by default (bulk if `CFG_TUD_VIDEO_STREAMING_BULK` is set). +- Adopts the frame interval requested by the host at stream commit. +- Blinks the board LED to indicate USB state (not mounted / mounted / suspended). + +## USB Descriptors + +| Interface | Class driver | +|-----------|--------------| +| 0–1 | UVC video (control + streaming) | + +## Configuration + +Notable `tusb_config.h` settings: + +```c +#define CFG_TUD_VIDEO 1 +#define CFG_TUD_VIDEO_STREAMING 1 +#define CFG_TUD_VIDEO_STREAMING_EP_BUFSIZE 256 +#define CFG_TUD_VIDEO_STREAMING_BULK 0 // 0 = isochronous, 1 = bulk streaming +``` + +## Building + +CMake: + +```bash +mkdir build && cd build +cmake -DBOARD=raspberry_pi_pico .. +cmake --build . +``` + +Make: + +```bash +make BOARD=raspberry_pi_pico all +``` + +## Try it + +The device appears as a webcam. On Linux, find it with `v4l2-ctl --list-devices` and view it with `ffplay /dev/videoN` or any camera app. You should see scrolling color bars. -- cgit v1.3.1