Fluidsynth is nice because it uses soundfonts, which are free and tweakable. It can also be controlled with pyfluidsynth, which is good since the stompswitches and LCD will be controlled with python. The box will run on a 5V adapter plugged into the USB-B port. When the PI boots, it will automatically start the jamPi.py script as a service, which starts fluidsynth and connects any midi devices. It will also read a file describing the presets - which soundfonts to load, which programs to load for each midi channel, and what effects/settings to apply to each program. The presets file should be easy to tweak - I'll plug a wifi dongle into one of the free USB ports - that way the user can ssh in and reprogram the stompbox in any way that's desired.
Major hurdles:
- Extend pyfluidsynth to allow more control of Fluidsynth's parameters
- Hack Fluidsynth to allow user control of the resonance/cutoff filter - is this possible?
- Figure out how to fit everything inside a 1590BB style stompbox
This is bloody marvellous!
A Pi based stompbox is a very versatile build.
I'd love to explore using one for recording, or even just effects!