The audio amplifier is pretty straightforward, based on a typical application found in the data sheet. He put it all together on proto-board, although soldering the FM radio module was a bit tricky.

Armed with an Arduino and a RDA5807M FM radio module, T. K. Hareendran shows us how to get started. Aspencore network. ... (AFL and AFR) of the radio to the line input of the PAM8403 audio module.