Pico SDR

Very cool. Quick note on the SNR, though. My understanding is that every bit gets you 6, but maybe with this architecture that's not the case. Regardless, SNR is unitless so it's dB, not dBm. It's a very common mistake and I made it a lot starting out. The rtl tcp bridge is an great way to quickly leverage existing work.

I think using the PIO on a Pico to drive a Tayloe mixer could be very productive. My interests are in multichannel SDR for doing passive radar.

I first thought I could use a square wave, and an NCO to generate any arbitrary frequency from my FPGA board... but was quickly disabused of that notion when trying to generate small offsets generated clicks at that offset. What can be done, however, is to get near the frequency, down convert the signal (with the Tayloe mixer), A/D to get IQ signals, then complex multiply to get to the frequency in question, and finally low pass filter and demodulate.