Do you have an old FM receiver that lying somewhere in your garage and you don’t know what to do about it? Instead of dumping it, would you mind to upgrade it to a fully functional RDS Recorder?

For your information, RDS or also known as Radio Data System will enable radio stations to send digital data along with the normal sound information, which you can receive with your radio set. Normally, this data is used to transmit information about the radio station, such as name, alternative frequencies, the current broadcast, traffic information etc.

Today, you’re going to build a RDS Decoder with a microcontroller from Atmel, where the decoder is fed by a RDS demodulator IC that has RDDA (data signal) and RDCL (clock signal) outputs within it.

The microcontroller is an Atmega168 clocked on the external 4.332MHz crystal from the RDS demodulator. You can use the TDA7330B RDS demodulator IC to connect to the Atmega168 with RDDA that connected to PD4 (on PORTD) and RDCL to INT0 (PD2).

When the Atmega168 is successfully decodes something, it will send the outputs on its USART port to the PC that is running a terminal program.