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Inside a $1 radar motion sensor
llar radar motion sensor(Electronics) (Wireless communication and power) I recently got some cheap RCWL-0516 microwave motion sensors, mostly because I was wondering how China managed to make a radar for under a dollar: Getting one working was quite easy, I just connected the VIN pin to 5 volts, GND to ground, and added a 1 uF decoupling capacitor on the 3V3 pin. When someone moves within ~5 meters, the OUT pin goes up to 3 volts for 3 seconds.
Jun 28, 2024 ( Electronics) ( Wireless communication and power)I recently got some cheap RCWL-0516 microwave motion sensors, mostly because I was wondering how China managed to make a radar for under a dollar: This trace is actually enough to figure out what the frequency the radar is using: While the laptop was moving, there were 8 peaks, meaning that the round trip path length changed by 8 wavelengths. I suspect the ring structure at the back is just to prevent oscillation at other frequencies, many very similar sensors don’t have one, or just use a solid ground plane.
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