Over on hackster.io we've seen a story about how maker Jon Dawson designed a self-contained software-defined radio based on the Raspberry Pi Pico that can receive 0 - 30 MHz, with up to 250 kHz of bandwidth. The Raspberry Pi Pico is a microcontroller board based on the Raspberry Pi Foundation's own RP2040 chip.
The Pi Pico Rx's front end consists of a Tayloe Quadrature Sampling Detector (QSD) mixer which makes use of the PIO (Programmable Input/Output) feature on the RP2040. The circuit also has an encoder knob for tuning and a small OLED screen.
Jon had originally created the Pi Pico Rx on a custom PCB, however, his latest work brings the cost down by showing that it can just as easily be implemented on a breadboard with through-hole components.
The full writeup can be found on Jon's blog "101 Things", as can the open source firmware. He has also uploaded a YouTube video explaining and demonstrating the project which we've embedded below.
Software Defined Radio with Pi-Pico