- Payphone. payphone.com was the first site I checked. So it is possible there are even cheaper options out there.
- Payphone mounting bracket. Remember these phone are cast iron, thus insanely heavy! I would NOT recommend trying to mount them without the bracket.
- Adafruit MP3 Maker Shield.
- Arduino Mega. The MP3 Shield uses a LOT OF PINS so the smaller Arduino's will not work well for this hack.
- Adafruit 20W Amplifier.
- 20W Speaker. Adafruit sells this one.
- 3W Speaker. Use this if you just want ringing but no music.
- Typical stuff: wire, headers, tape, soldering iron, etc.
see attachment. ** Give it a read! Lots of helpful comments in there. **