My idea is to attach a radio transmitter/receiver module that is capable of sending and recieving audio to the data port of a phone and utilize the phone's microphone/battery/speaker and have an app that handles the data, so you can talk to others without celluar service.
Is it possible to take audio data from the phone and transmit through the radio and audio from the receiver to the phone through just the micro usb port and/or headphone jack of a phone while still powering the device? What kind of components are necessary to do this and is it even feasible? I know arduino walkie talkies are definitely possible, but I was wondering if all this could be integrated with a phone.
If anyone could give suggestions/advice, that would be fantastic.