Here are the initial concept features. My immediate needs are simple, and time-constrained!

V1 FEATURES

  • 6-PIN SAO input
  • 2 QWIIC ports
  • MIDI 5-pin DIN IN and OUT ports with proper isolation, optional pass-through
  • GPIO1 Badge TX, SAO MIDI OUT
  • GPIO2 Badge RX, SAO MIDI IN
  • Prototyping area

The next version might extend beyond just MIDI, and include I2C or at least a DAC with audio amplifier to enable audio directly from a badge's GPIO pins.

V2 BRAINSTORM

  • MIDI 1/8 TRS IN and OUT ports, optional pass-through
  • DAC Audio amplifier and speaker output terminals
  • Speaker
  • I2S Audio amplifier and speaker output terminals
  • Solder Jumper configuration of pin usage to audio amps
  • 2 buttons
  • Optionally route I2C through the 5-PIN DIN