Android Bluetooth Dual-Joystick Controller

Sends 5 bytes every 200ms (or every 3 sec if idle).
data format: [ STX : radiusL : angleL : radiusR : angleR ]
where: STX = 0x55
radius = {0..10}
angle = {0..35} (or actual/10)

modifications:
* preference menu (e.g. "Menu->Connect" & "Menu->Options" )
* add four customizable buttons (send either an ascii char or a string)
* immediately send joystick data when a joystick returns to center position
* selectable data format, intervals and timeout
* prevent accidental closing