Hardware: Romu board, USB Type-A cable, PC with DAW software (Ardour, Ableton).
Environment: Install MicroPython or Raspberry Pi C/C++ SDK. Configure your IDE for debugging via UART pads if needed.
Code: Import the USB MIDI library. Define a callback function for the RGB LED to indicate connection status. Map the single Romu button to a Note On/Off message on channel 1.
Compile: Compile the firmware in 'Release' mode to optimize size. Ensure the USB descriptor is correctly configured as a MIDI class.
Flash: Plug the Romu into a USB port. Hold BOOTSEL (via pads if necessary) to enter UF2 mode, then drop the .uf2 file.
Verification: Open your DAW. Romu should appear as a MIDI input device. Press the button to trigger a note. The LED should light up green.
Deep Dive: Add an external accelerometer via I2C (on pads) to control pitch bend by tilt.