It's useful to have a few push buttons, LEDs, pots, etc... when prototyping embedded audio ideas, and that's exactly what Electrosmith's Daisy Pod gives you -- plus an encoder. That being said, it's been a bit of an adventure uploading files. But some progress was made today.
Running the Arduino IDE threw up errors, and requires some finangling with an STM32 factory bootloader. Plugdata (a vanilla Pd wrapper with compiling capabilities) kept hanging during file management. However, the web programmer worked a treat -- and it allows you to upload your own binaries. So... if I can go from Pure Data --> C/C++ --> PCB (which the Python-based Heavy Compiler Collection, hvcc, allows) then we should be motoring.