Charles Pax is making an Arduino shield for the old Nokia phone:
The cheapest and most common old phone we’ve seen is the Nokia 3100. There’s no camera, no Bluetooth, no WiFi, no frills at all. Perfect! We can pick it up in the market for just a few dollars.
This is a pretty old phone and there is no guarantee it will work on a modern mobile phone network. Our test phones are confirmed to send text messages on the China Mobile network in Shenzhen. We will have to do more tests around the world. If you have tested the Nokia 3100 or similar phone in your area, please post in the comments below.
Before we design a PCB we’ll have to determine how everything should be connected and slap it on a breadboard.
Via the contact form.
Project info at Pax Instruments.