MIDI Test
A USB MIDI device that continuously plays a fixed melody, useful for verifying USB MIDI enumeration and streaming.
What it does
- Sends a repeating sequence of note-on / note-off messages (cable 0, channel 1) about every 286 ms.
- Drains any incoming MIDI packets (read and discarded) so the host sender never blocks on a full input port.
- Blinks the board LED to indicate USB state (not mounted / mounted / suspended).
USB Descriptors
| Interface | Class driver |
|---|---|
| 0–1 | MIDI (Audio Control + MIDI Streaming) |
Configuration
Notable tusb_config.h settings:
#define CFG_TUD_MIDI 1
#define CFG_TUD_MIDI_RX_BUFSIZE (TUD_OPT_HIGH_SPEED ? 512 : 64)
#define CFG_TUD_MIDI_TX_BUFSIZE (TUD_OPT_HIGH_SPEED ? 512 : 64)
Building
CMake:
mkdir build && cd build
cmake -DBOARD=raspberry_pi_pico ..
cmake --build .
Make:
make BOARD=raspberry_pi_pico all
FreeRTOS variant
A FreeRTOS build is in examples/device/midi_test_freertos — identical MIDI melody playback, with the device, MIDI, and LED-blink work split across FreeRTOS tasks.
Try it
The device shows up as a MIDI port. On Linux, list ports with aseqdump -l, then watch the incoming stream with aseqdump -p <client:port> (you should see a steady run of note on/off events), or route the port into a synth such as FluidSynth/qsynth to hear the melody.