Pico radio is a simple raspberry pi pico based FM receiver that uses rda5807m to tune to FM channels. One can listen to these FM channels by attaching an FM antenna in the SMA connector and a 3.5 mm headphone in the audio jack.

Hardware build:

The hardware is very simple and easy to use. It consists of the following components:

• an OLED display for showing radiofrequency and FM channel info.
• a tack switch or push-button for changing channels.
• a LED for indicating signal strength.

You need to surface mount the Pico onto the PCB.

The project can run on USB power itself if you connect the raspberry pi pico to either a computer or a power bank. But for portability one can attach a 3.3v LiPo battery to the ground and VSYS pin of raspberry pi pico along with the LiPo battery charger and an on/off switch.

If you own a 3D printer, then you can also 3D print the case for this radio and make it portable and handy. The 3D print files are available here.

Software Code:

If you don't want to get into the hassle of understanding the code for the build, you can directly download the .uf2 file from here.

The project is actually a modified version of the example mentioned on pico_rda5807 library.

Additionally, I have included the support for OLED Display (Using pi-pico-ss-oled library), LED, and Button Input.

Project Controls:

OLED will display basic info such as Tuned Frequency, Station Info, and Signal Strength.

For changing stations, one can press and release the tact button quickly to loop through all the available stations.

For increasing the volume, one can hold the same button and volume will loop from 0-15 and then back to 0.

Additionally one can get access to full features of rda5807 as mentioned in pico_rda5807 library by accessing the serial console.

USB Implementations:

I have also connected the Left Speaker output to GPIO26 (ADC Pin) and Right Speaker output to GPIO27 (ADC Pin) of Raspberry Pi Pico which will allow usera to use Raspberry pi Pico as a microphone input to any PC or a Laptop. So on connecting the Pico radio to a laptop or a desktop, one can listen or record radio broadcasts using recording software such as Audacity or Windows default recorder.