When I built the pedalSHIELD UNO and a clone, I started collecting my code in an AudioDspDriver class library. I’m liking the encapsulation and reuse it provides over just hacking sketches based on the pedalSHIELD examples. So this project is an exercise in implement the equivalent of all the pedalSHIELD UNO examples. As always, all notes, schematics and code are in the Little Electronics & Arduino Projects repo on GitHub