PicoStepSynth proto w/ CircuitPython synthio

Trying out some synth interface ideas in CircuitPython using one of my "picostepsynth" (aka "picostepknobs") proto PCBs and synthio.
I really want to use pots, but I also want the pots to do multiple things. So figuring out a "knob pickup" algorithm that works intuitively is challenging. I'm getting close tho.
#raspberrypipico #circuitpython #synthdiy #synthio #rp2040

[@Keeping_IT_Simple]

i want one ( or 2 or 3 or more!!)

[@relic985]

How did you end up avoiding the issues with displayio interference? And great job on the pcb! Though, how practical do you think it is to directly integrate the PCM5102a rather than use the module?

[@relic985]

Ooohhh! Just looked up your source code. I didn't realize you were using an SPI display rather than I2C. Nice to know that I2C is the bottleneck and SPI is the solution. :)

[@todbot]

Thanks! There's sort of three tricks to getting CircuitPython audio not-glitchy when using a display:
- Use "AudioMixer" and set a buffer of 4192 (or larger)
- Change only the minimum amount of screen area as possible (using displayio Groups helps with this), do not do full screen redraws
- Use SPI instead of I2C

[@todbot]

As for PCM5102 chip, the cost of adding all the parts of that module was a bit higher than just using the module, and getting audio circuits "right" can be challenging. So for this proto, I went for the module.