Wow, cool project, looking forward to it. I was just yesterday asking in the slack chanel about trezors integration of iota.
Also I am wondering about the durability of such a device. When I have an old USB stick most of the time its broken or corrupted. Can that happen here as well?
Offtopic:
Allthough I have no Idea about programming chips this remembers me of when I was building a drone with On Screen Display. The OSD also used an Arduino and I had to program it with the same USB Adapter above. The flightcontroller is a Flip32 Chip btw.
RE: BOLSHOI - comprehensive IOTA wallet - Hard Work - Working with Hardware