If you are a enthusiastic Electronic student or hobbyist, then you must have tried to build FM Radio Transmitter Circuit, which includes so much circuitry. But here is the simplest DIY FM Radio Transmitter, I have ever heard. This only requires a wire as antenna and Raspberry Pi Board as engine, and of course a power supply for PI.
PiFM was originally created by Oliver Mattos and Oskar Weigl, and revised by Ryan Grassel. MAKE Labs engineering intern Wynter Woods, further contributed to this project and developed a Python Script PirateRadio.py. And they have named this simplest and powerful FM Radio Trasmitter as: Raspberry Pi Pirate Radio.
This Radio just needs a Wire, as antenna, to be plugged in GPIO Pin 4 of Raspberry Pi. Although any wire can work, but 40cm 12AWG Solid Copper Wire is recommended for a good range. You can experiment with Antennas to get high range of 500 meter. Then you can run their python script PirateRadio.py in PI, or if you are not familiar much with Pi, they have made a Disk image, which is just need to be flashed in SD card and you are done. This Image will do all for you, just insert the SD card in PI and power it On, script will load automatically on start-up and music broadcasting will start within 15 seconds.
You can also add your favourite music files at the root of the “Pirate Radio” partition of the SD card. There is a config file (pirateradio.config) to set the broadcasting frequency, Shuffle on/off, Repeat on/off etc. Remember, set your frequency in standard FM band of 87.5MHz–107.9MHz, which should not interfere with Government Frequency bands.
Now just get a FM receiver, tune to the set frequency and listen the music. Also use USB power battery to carry it anywhere.
So let’s try this and feel the power of Raspberry Pi.