This project uses the library RDA5807 from Ricardo PU2CLR. All credits and acknowledgements goes for his great work .

What is it?

This project was designed around the RDA5807 DSP FM Radio chip. Interfaced with an ATMega8 clocked at 16mhz and utilizing the breakout board TM1638 which is widely available and offers 8 seven segment displays and 8 LEDS and 8 switches to form the front interface of this project FM Stereo Radio. An audio Amplifier PAM8403 Stereo Class D is also provided on the board and provides enough kick for this project ! Two regulators provide the necessary supplies 5v and 3v3. FM input is through an SMA edge connector and diode clamping is provided on the pcb.

I have optimized the code to show the status of every button on the seven segment . Thus pressing the button will show the status as :

Button 1: Manual tune Down Button 2: Manual tune Up Button 3 : Frequency scan - shows dial of frequency scanning Button 4 : Vol Down (With Level of Volume) Button 5 : Vol up (With Level of Volume) Button 6 : Mute on - Mute off Button 7 : Stereo - Mono Button 8 : Bass on - Bass off

Why did you make it?

The radio was made as the board has been provisioned for an upcoming project - so it has been designed to also have on board the following features :

Keypad buttons to have menu options

Provision for a rotary encoder

All unused pins are on a single in line connector

I2C BUS is provided on another connector.

Serial Port is provided on a single in line connector

Radio Specifications

Tuning Range : 76 - 108Mhz

Audio Output : Stereo 2 channel 3Watts

Input Supply Voltage : 9-12V - Positive in Middle 2.1 D.C Barrel

Bass Boost Button

Stereo/Mono Button

Mute Button

Volume Up/Down Button

Seek Button

Tuning Up/Down Button

Encoder with tune up/down and button performs a scan of frequency

What makes it special?

The board can be interfaced with other displays easily - both supplies are available 5V and 3V3. Also the board has all processor pins on a connector and can be interfaced with other hardware easily.