Unlike infrared optical sensors that use an LED transmitter and IR receiver, the PIR emits nothing. As its “passive” name suggests, it responds only to infrared energy radiated by the object being ...

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.

A few weeks ago, Aqara was in the news with the release of its new P2 motion sensor. I am a big fan of motion sensors for smart homes as they allow for some pretty rad automations based on who’s in a ...