I wonder what a RPi 2040 could accomplish with its dedicated realtime components. Add a variable (center frequency and bandwidth) bandpass circuitry to filter out nasty harmonics and I'd guess you can at least go for purely software transmitting CW (morse code), FM and the various digital modes like DMR that are AFAIK all variations of either straight FM or FSK.
FPGAs are too expensive / require too niche knowledge to pull it off, and regular GPIOs suffer from hardware interrupts...
The other question of course is how to receive, but I guess for that you can use an RTL-SDR...
I wonder what a RPi 2040 could accomplish with its dedicated realtime components. Add a variable (center frequency and bandwidth) bandpass circuitry to filter out nasty harmonics and I'd guess you can at least go for purely software transmitting CW (morse code), FM and the various digital modes like DMR that are AFAIK all variations of either straight FM or FSK.
FPGAs are too expensive / require too niche knowledge to pull it off, and regular GPIOs suffer from hardware interrupts...
The other question of course is how to receive, but I guess for that you can use an RTL-SDR...