Yaaar! Become your very own pirate radio station with this FM radio transmitter. This breakout board, based on the best-of-class Si4713, is an all-in-one stereo audio FM transmitter that can also transmit RDS/RBDS data!
Wire up to your favorite microcontroller (we suggest an Arduino) to the I2C data lines to set the transmit frequency and play line-level audio into the stereo headphone jack. Boom! Now you are the media. Listen using any FM receiver such as your car or pocket radio receiver - this is an easy way to transmit audio up to about 10 meters / 30 feet away.
This transmitter even has RDS/RBDS support - that's text/data transmissions that many modern FM receivers support. (It's how some car radios can display the FM station and current song playing). You can transmit just about any text you want, set the station identifier as well as the 'freeform' buffer.
Best of all, you'll be up and running in minutes with Adafruit's awesome Arduino library, example code and tutorial!