I hope that VOLUMIO can build a api that can exchange the basic music info,
for instance ,the volume control can pass the current volume value by UART on the arm board
and by UART , Arduinolike micro controller can then react like control PGA2311 or Some kind of 1602 LCD
or the user can choose the Output “port” by using microcontroller control relay.
I think that VOLUMIO can using the resource that the various Arm board provide.