If the device isn't seen as a MIDI input (USB endpoint pressure from drive+serial+HID+MIDI),
boot.py disables the unused HID interface and enables usb_midi — copy it on and power-cycle.
Bundled into pm_k1_circuitpy.zip; documented in the README.
Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>