Old dial phones never die - they just get hacked! And in this case in a very useful manner. Arduino enthusiast Andrew F has modified a typical rotary dial phone by using an Arduino board to decode the signals from the dial. Once a telephone number has been dialled, the Arduino 'presses' the buttons from a cordless telephone handset PCB hidden inside the rotary phone. The Arduino's digital outputs are connected to the cordless PCB via optocouplers, and with it also monitoring the hook switch, can then dial the number to call and press 'send' just like a person. Once the handset is replaced, the call is ended.
If you're thinking of embedding an Arduino-compatible board in your next project or rotary phone, consider using the Freetronics LeoStick:
Apart from being one of the smallest Arduino-compatibles on the market with USB, it also has an onboard RGB LED and piezo which can be used a knock sensor and various tune and sound effects. Plus you can add extra circuitry with the matching protostick! For more information and to order, click here.