hello,
i am an expert of hardware integration, communication protocols and advanced M2M projects. serving my my worldwide clients. the most recent project that i have completed on freelancer, related to this one is NSP project which is a protocol to communicate between controller/power module of a nano satellite.
anyway, reading your description, i find that you are talking about USB based link between machine and the android device, in such case what is the communication medium used ? is it serial ? in such case does your device support USB client ??
also , do you have already selected the android module that support "Serial Over USB" ? and let's say we are developing this, how do you plan developer to test the protocol ?
let me know if you are interested. i may have more questions as above are answered.
thanks,
mihindu