O.K. ... here's a new one on me ... A friend wants to put a cellphone (as a data link) into a remote automated site where there are no phone lines or other comm facilities. He has size and weight limits, though he didn't tell me what they are or why. Just as proof of concept, whatever that is, he wants to use a cellphone channel to send his data, whatever it is, back to a base station. How can he operate the cellphone without a human to push the buttons, etc?

I suppose he could put FET switches across the keypad matrix to synthesize keystrokes and he could look for the row and column strobes to tell him when each was present. Is there any reasonable way to interpret the incoming signal in order to "talk" to the local MCU? Where's a good place for him to start? He's not an electrical engineer but does have some experience with microprocessors from back when he was in college and earlier. He also has access to equipment, e.g. my lab, where there's some pretty sophisticated hardware, AND he's pretty smart. He's going to be busy with other considerations, though, and I told him it might be clever to investigate this way of establishing communication.

Any suggestions?

RE