Yeah, I know Arduino is really low power and cheap, but these days you can spend like $35 to get a Rasp. Pi (or equivalent) small computer for actual compute gi

Yeah, I know Arduino is really low power and cheap, but these days you can spend like $35 to get a Rasp. Pi (or equivalent) small computer for actual compute girth for an application. Alternatively, a UART-to-wireless link could connect your data-stream to a server somewhere for stronger processing. My guess is that you need something incredibly small power-usage, that must run on Arduino only. A lot of FFT projects I'm thinking of are just... crappy SDRs. Maybe audio is "slow" enough that an Arduino's FFT is fine, but most applications are probably doable with just regular digital filters.