circuits/midi.py, a do-not-populate option (USB-MIDI is the default). H11L1 opto-isolated
IN (breaks the MIDI ground loop), 74LVC14-buffered OUT (TX through two inverters) and THRU
(re-buffered IN). Connector is a face choice; core exposes the loop nets MIDI_IN/OUT/THRU_A/B
plus MIDI_TX/RX to the RP2350 UART. ERC 0 errors; netlist 0 errors.
CONFIRM: H11L1 pinout (standard; datasheet fetch timed out) + 3.3V-MIDI series-R values.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
