I am a collector of antique phones. Most all of them are dial phones which will no longer work on most telephone networks or certainly not with any VOIP adapter that I have seen.
Have any of you done or seen a project that uses Arduino to detect pulse dialing and then converts it to touch tone sounds to allow an old phone a new lease on life?
i have seen these two ways.
A module inside the phone that interfaces at the actual dial mechanism and generates tones that mix back into the phone line.
A module that has a modular plug that you plug the phone into which senses when the receiver is lifted and then converts the pulse dialing to the appropriate touch tone frequencies.
I think this would be a fun Arduino project.