Raspberry Pi in Rotary Phone

I have a similar project, 90% finished, with a wifi enabled Rpi4 that uses asterix as a soft phone and can be used as a classic rotary. Some notes:

  - As the creator of this music phone I had hoped to keep the original mic and speaker. This turned out to be more work than I was willing to do as those were both 24V devices, not suitable for Rpi integration without extra electronics.

  - I also had hoped to keep the original handle chord. This also turned out to to be impossible as the original mic and speakers shared a common 24V+. So 3 wires in total in the chord, I needed 4 for the new mic and speaker.

  - I also ripped out most of the ringer mechanics, but kept the bells. The bells are now hit with a piece of heat shrink tube on the end of a small motor.

I did the same thing to a numpad phone (also old) about 2 months ago. I squeezed a pi zero-w into the chassis and wrote some software to bind each key from 0-9 to a song and then used the Pi's Bluetooth module to play the sound on a speaker across the room. I also have a button that reads out the current time and it runs a website to upload new songs and change the bindings. It was a really fun project and I am surprised someone had the same idea!

My child is old enough now to stay home alone during short errands. Since we don't have an old school land line it would be cool to take inspiration from a project like this and build her a "red line" device that gives her immediate access to reach me without breaking down and buying her a cell phone yet.

But what would I hack together for the software side of that?

I love these sorts of projects. This is a really slick integration.

Another similar project: https://www.stavros.io/posts/irotary-saga/

I made something similar using another instructable(1) with a simpler approach a couple of years ago. Great fun, and relatively easy to do (it was my first 'hardware' project and I knew nothing about electronics).

I kept the speakers and all intact and it still sounds fine. I loaded it up with some fairytale stories, 1 for each single number you can dial.

1: https://www.instructables.com/Fairytale-Phone/

I've been meaning to build a similar project for my SO. I want is to be able to connect the rotary phone via bluetooth for calls (only calls) and dialing if possible. Has anyone worked with anything similar that can provide some pointers?

I'm guessing the dialer part should be "simple" as I could probably connect an Arduino as if it were a keyboard but can't find much on the audio part.

I never realized what a perfect rpi case a rotary phone is. You can even fit a usb hub on there. And it can be quite stylish. And durable. And ez to cut the plastic for mods. And cheap. My eyes have been opened. I'd probably strip everything off it tho.

It could have been a hip IP phone also