This is a project that builds a Voip phone patch for ham radio. I built it for fun a while back and thought others might find it useful.
It has built in DTMF code detection with another library that was modified to support streaming audio (instead of prerecorded audio). To set it up, you can build a simple state machine. An example is shown in the phone patch kit.
For more info, read the pdf document. It also contains wiring diagrams for the kenwood style adapter.
This is licensed under the MIT license.