The presented schematic shows how to build a simple PIR motion sensor. PIR sensors allow motion sensing, it is almost always used to detect whether someone has moved in or out of the sensors range.

Recently, I exhausted my stock of common passive infrared (PIR) motion sensor modules and was looking for a new one to play with. I searched the web for a small type with self-contained electronics.

I set up my $25 WyzeCam v2 with the PIR Motion Sensor and Sensor Bridge accessory to catch some hummingbirds feeding. I can't use video motion detection because the feeder is constantly swaying in the ...