Our final project in this chapter is the ultimate in mischievous mayhem. We're going to use our Pi Zero to take over the airwaves by transmitting whatever audio we choose to a standard FM radio by using a rather nifty piece of software called PiFm. PiFm was originally written by Oliver Mattos and Oskar Weigl, and updated by a guy called Ryan Grassel.
The Pi Zero is perfect for this, because of its small size, and can be integrated with our wearable audio recorder built in Chapter 2 , Audio Antics, so you can interfere with FM radio reception out in the field.
Note
Very important: The laws for broadcasting FM signals—even over a short distance—vary from country to country. Ensure you check your local regulations before attempting this project.
In order to get range out of your radio jammer you'll need to solder a 20cm piece of wire to pin 4 of your Pi Zero's GPIO connector to act as an antenna. This should give a surprising range—perhaps up to 20 or 30 meters...