@DuaneB Thanks so much! Please do, I'd be honored to have this project added to the list. I'll definitely update the code with the volatile fix, thanks for the heads-up. Actually I must thank you for the output circuit - I played with your Illutron B project just before I started this one, so I still had your output circuit on the breadboard when I started this one. I've kept it for the final design.
@Giò LFZ I'm only sending note values (fixed velocity) and duration via MIDI - no cc's, though that's a good idea for Groovesizer V2 ;^)