A simple QTPy RP2040-based synth to experiment with synthio.

Features:

• Mono audio output circuit, converting PWM to audio, as per RP2040 design guidelines
• Optoisolated MIDI Input via MIDI TRS-A 3.5mm jack
• Two pots for controlling parameters
• One switch for controlling parameters
• Four capsense touch buttons for synth triggering
• USB MIDI in/out of course too

Some programs written specifically for this board:

• hwtest - test out the hardware with a simple synth

• simpletouchsynth - play with filters using touch sensors

• wavesynth - larger general two-osc synth that can also do wavetables

  • early video demo: "Wavetable synth w/ CircuitPython synthio on QTPy RP2040"
  • another demo: "More Wavetable synth w/ CircuitPython synthio on QTPy RP2040"

For many other synthio examples that can work with this synth with minimal changes, see: https://github.com/todbot/circuitpython-synthio-tricks