Converting a retro phone a bluetooth phone
I bought an old rotary phone, specifically an Australian 800 series . The plan is to enable bluetooth on it so that it can receive and make calls. There will be a number of challenges. These phones weren't designed to interact with mobile phone or Bluetooth. Mainly because Bluetooth didn't exist yet and "mobile" phones in the early 80's were huge things that stayed in your car and were very expensive.
First step is to break up the project into phases and smaller challenges.
Phase 1:
- Get the ringer to work. (Completed - Used an H-bridge with 2 9V batteries in series)
- Get an output from the microphone
- Get in input to the speaker. (Completed - Used a 300mV p-p square wave)
- Decode the rotary dial numbers. (Mostly completed - still needs tweaking to make it more accurate)