1W of continuous power consumption is not great. To put it into perspective: that’s 1x24x365Wh, almost 9kWh per year. A kettle (1.8-2kW) can run for 4-5 hours for that amount of energy. If getting a kettle to boiling takes 5 minutes, that’s almost 50-60 kettles. That’s two month of boiling one kettle a day.

Nice to see that it consumes barely any power. Looks like a fun and useful project!

yes and it's very cool! if you're interested in learning, i'd look into the filtering approach.

maybe could try pyfda and the filtering functions in scipy.signal to start playing around.

or if you have access to matlab it has some really excellent filter design tools.

regarding the hardware/dsp: many cpus include simd instructions these days, which basically are an interface to a hidden digital signal coprocessor. :)