there are ways/programs/apps to do this with smartphones and tablets now that would probably be the easiest way, and most of the better tablets have stand adapters now becuase alot of people use them for controlling DSLRs in pro photography as well as using them in music.
i have a friend who uses a Nexus through his boss pedal board (one of the big ones with a volume/wah build onto it and like 8 switches and such. i cant remember the model). he just has a bunch assigned to different "buttons" on the screen, tap the one you want, and off you go.
My Band SAHE