There’s a lot you can do with the tiny Raspberry Pi Pico board, but computer student and radio amateur Luigi Cruz decided to go a step further by making Raspberry Pico RP2040 board work as an SDR compatible with GNU Radio open-source toolkit.
PicoSDR PiccoloSDR project relies on one of the ADC pins from the Raspberry Pi Pico board to sample 8-bit data at around 500 ksps and makes the data available through TCP/IP (emulated via the RNDIS protocol) over the Full Speed USB interface at up to 12 Mbps.
As Luis notes applications are limited due to the low bandwidth, but it’s still a fun project. You can see demos with a web-based tone generator, a PWM generator, and actual audio where we see the spectrum chart, scope plot, and FFT plot updated in real-time.
He has not released the demo code “officially” just yet, but I can see that he committed some “picosdr” code on his pico-stuff Github repository, notably in apps/tcp_server/ where the TCP server code running on Raspberry Pi Pico resides.
Once the code is ready, he’ll probably announce the source code release on the Twitter thread who brought this fun little project to our attention.
[Updated March 12, 2021: Since PicoSDR is trademarked, the project has been renamed to PiccoloSDR]