I’ve written a door pi software that not only controls

• Intercom door open function on buzzer detection
• Kasa Smart sockets  (to control heaters)
• Infrared smart hoover (coredy R500)

But I’m also working on pulse width modulated audio to play audio file down the line to the person at the intercom.   Actually i have it done, just need to push the PCM code once i have sorted the audio amplification.

https://github.com/dmzoneill/ashtangayogacork.ie-doorpi