Low cost hand waving detection

Looking for a low cost method for detection of handwaving for outdoor Halloween animatronic figures. Just needs to detect waving motion of kids in Halloween costumes in the range of about 2 to 5 feet, to be implemented on something like an Arduino ESP8266 or RPI0. Can it be done for < $10? I thought maybe just FFT the whole screen and look for a strong signal in the hand-waving frequency range.

P.S. Total newb to OpenCV but long term Arduino hobbyist…

to find motion frequency, you’d need an image sequence

however, opencv has Background Subtraction Methods , might get you started easier

you want “gesture recognition”.

that commonly implies “pose estimation”

might be easiest if you get a raspberry pi or old computer, then run mediapipe on it.

don’t ask me if an RPI 0 is powerful enough. it might be. “arduino” is irrelevant. you need to talk about what runs the processing, not what eventually uses the information to flip some lights. the usual arduinos don’t even have the power to ingest video.

If it’s just motion and not specific gestures, I might consider skipping the camera altogether and try something more basic. I’m thinking of the type of sensor used in automatic faucets or paper towel dispensing systems. I think IR LED + detector, but I’m sure there are other ways. I imagine that would be pretty inexpensive.

If you want to use a camera, then I agree that looking into background modeling would be a good place to start.