My Chrismas/NewYear holiday project was this frontend for the RadioBerry/HermesLite2 SDR that gives the user, some knobs and switches.. It has been a fun project, far from complete. The board design was by a friend of mine VU2XTO.
The switches and knobs go into a Raspberry Pico running a C program. Pico interfaces to a Raspberry Pi4 fitted on the back of the above PCB via USB.
I can think of all kinds of CS topics that turns up in this little project - notably consistency, atomic updates to values, state management, communication protocols...
I wish CAT has some kind of standardization across different radios (I am using the FlexRadio commands) and I also wish there is an initial handshake between client and the radio
The board also does filter switching, On/Off switch, Antenna switching, PA bias control etc.
And the software is getting better and better and good to use as a daily driver now. The couple of days I spent reorganizing the code turned out to be a great decision. Now, adding new features is a lot easier.