Newer model cellular phones are connected to USB and also my old Ericsson T68i could communicate via USB if the cable has built-in USB -> Serial converter.
How does this work?
Seem to me that all new phones still use AT Commands.
Is it as simple as connecting an FDTI232R chip in btw and feed it with the same AT Commands from AVR side and get the "normal" replies from the phone?
And that all "modern" cellular phones have cables with a built-in USB -> Serial converter?