
Cellular Rotary Phone
I completed this project at roughly 14 and it was my claim to fame for a while after. I had been exposed to rotary phones during one of Maine’s very common power outages, since our cordless phones didn’t work through a power cut. The three components of the phone were an Arduino Pro Micro, which interpreted dial/hook voltages, and coordinated calls an Adafruit Fona 2G, an amazing board that is basically a Nokia 3310 on a breakout board. It broke out speaker/mic pins, and had a serial interface. It’s sadly been discontinued with the phase-out of 2G, and nothing VoLTE has really replaced it. a Sparkfun WAV trigger, for playing the ringer sound effects. It is basically a board that will play short audio effects when a pin is triggered. This project originally used schematics from an ancient Sparkfun to generate a voltage to use an actual ringer (this project has been done a few times by other folks. Convergent evolution will get you every time). However, my electrics skills/equipment were woefully unprepared, and I kept burning out H-bridge chips. The WAV trigger connected to some salvaged laptop speakers did the trick.
