I've been thinking that, since many android phones support USB OTG maybe there could be a way to engineer a device that performs special task and uses phone as it's control panel.
But before making this serious idea, I need to know if it can work.
- How does android handle unknown USB devices?
- Can application use USB directly without ROOT privegies?
- As an alternative, does android support virtual COM port?
- As the last hope, can applications directly read/set value on headset output? (To use it as digital IO pin)