Get close enough to this raven and you’ll set off the PIR sensor, which triggers lighting ... This bird’s brain is an Arduino Nano, which is protected from the 12V supply with a boost converter.

As an example, [Circuit Valley] has an IKEA Vallhorn motion sensor for a teardown, it’s as you might expect, a passive infrared sensor (PIR) sensor coupled with a Zigbee interface. Inside the ...

(Passive InfraRed sensor) A device used to detect motion by receiving infrared radiation. When a person walks past the sensor, it detects a rapid change of infrared energy and sends a signal.