The hardware is consists of an Arduino microcontroller (here an Arduino Uno R3) and a pre-wired soil moisture sensor module. The soil moisture sensor module , built around the LM393 comparator, gives ...

Because some hardware setup is required to build up a functioning radio, an Arduino can be used to supply the voltage and control the radio chip. The 3.3-V power can be taken from the Arduino’s ...

He put it all together on proto-board, although soldering the FM radio module was a bit tricky. The Arduino code is quite simple, and available for download (zip file).