First of all I'm not here to contest dmitri's work, honestly I believe this project is incredible and what you've done to the edrum diyers is amazing! Thank you!
I've been reading and searching about minipcs based on arm microprocessors, some based on android and some based on Linux, accordingly MK808 and iMX233.
The later one seems like a cool start for a project like the one you have here and with the recent updates on megadrum with the ARM microprocessor a question arises on my head, what are the benefits of building your entire schematic based on an arm micro instead of using one of the pre-built "minipcs" that have a lot more processor power and opens the door for some cool stuff like video output and integrated usb?