This library provides a convenient interface to the RDA5807 FM radio chip from RDA Microelectronics. It targets the Raspberry Pi Pico and similar RP2040 based boards using the C/C SDK.

Main controls:

• FM band (87-108 / 76-91 / 50-76 MHz)
• channel spacing and de-emphasis
• seek sensitivity
• volume
• softmute (mutes noisy frequencies)
• mono / stereo output
• bass-boost

Features:

• tune / seek the next station without blocking the CPU
• monitor signal strength and stereo signal
• RDS - decode station name, radio-text, and alternative frequencies

A test program is included. To interact with it, establish a serial connection through USB or UART.

RDA5807 - test program
======================
- =   Volume down / up
1-9   Station presets
{ }   Frequency down / up
[ ]   Seek down / up
<     Reduce seek threshold
>     Increase seek threshold
0     Toggle mute
f     Toggle softmute
m     Toggle mono
b     Toggle bass boost
i     Print station info
r     Print RDS info
x     Power down

Follow the instructions in Getting started with Raspberry Pi Pico to setup your build environment. Then:

• clone repo
• mkdir build, cd build, cmake ../, make
• copy fm_example.uf2 to Raspberry Pico

Communication is done through I2C. The default pins are:

When powering the FM chip straight from Pico 3v3 OUT there is a fair amount of noise, so a separate power supply is recommended.

pico_si470x is a similar library for the Si4702 / Si4703 FM radio chips.

Valentin Milea [email protected]