[fennecfoxy]

I looked at mmwave stuff for my own setup but I just couldn't get over it triggering on things like ceiling fans etc moving, curtains rustling.

I think the idea of presence detection is such an interesting problem, really an AI camera is the best solution but nobody wants cameras all over their house. There's also thermal imaging with sensors like MLX90640 which is a very low res thermal sensor.

Seems to work pretty well for the most part, had a bit of a play with it but not actually built something to be put in the home yet but the only drawback is static heat sources like radiators obscuring moving heat sources like a person.