I got the Pi Pico DCO working! It uses PIO to generate a highly accurate frequency. The “analog” oscillator part is based on the Juno 106 same as Arduino Nano based DCO. This time I ommited expensive external parts like ADC/DAC and use PWM smoothing for amplitude compensation. It is controlled by USB Midi, I think I will also add DIN Midi. It should be able to drive 8 separate oscillators because there are 8 distinct state machines that control GPIO pins. Currently gate output and some Midi programming is missing, maybe I will make it even polyphonic.
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