Turning the Raspberry Pi Into an FM Transmitter – Imperial College Robotics Society Wiki January 16, 2013Posted by sandyclaus in Academic Technology, RPi Tutorial and Programming.
Below is some code that was hacked together over a few hours at the Code Club pihack. It uses the hardware on the raspberry pi that is actually meant to generate spread-spectrum clock signals on the GPIO pins to output FM Radio energy. This means that all you need to do to turn the Raspberry-Pi into a ridiculously powerful FM Transmitter is to plug in a wire as the antenna as little as 20cm will do into GPIO pin 4 and run the code posted below. It transmits on 100.0 MHz.