What if i tell you that you can easily transmit FM signal from your RaspberryPi without using any extra hardware. Impressive at least huh? Well today I saw a video in OreillyMedia youtube channel explaining on how to do it. Actually you only have to download – install an app and then run it. You pass the frequency and the sound file source as arguments and that it. Have a look at the video below. People say in the comments that you will get up to 50m with a 20cm antenna!