FM Radio Transmitter Module
Build your own FM stereo audio transmitter with this neat module from PMD Way. Before you get excited, this has a default range of around 40 cm. The controller IC was orginally designed for those car FM audio transmitters.
However you can solder more wire onto the board for an external antenna. Click here to learn how to calculate the correct antenna length.
The module is based around the KT0803K IC (download the data sheet [.pdf]). This requires control via the I2C bus at 5V DC. The bus address is 0x3E.
You can set the frequency between 70 and 108 MHz..
There is an Arduino library you can download from here. Inline header pins are included but not soldered to the board. Free delivery, worldwide.