[ladyada] has a freshly-published and amazingly thorough tutorial on passive infrared (PIR) motion sensors. Most often seen in security floodlights and automatic doors, in creative hands these sensors ...

IR sensors rely on an emitter (IR LED) and a detector (photodiode or photoresistor) to measure infrared light and convert it ...

Motion sensing is the detection of the change in position of an object relative to its surroundings or vice versa. There are many kinds of motion detector methods: infrared, optics, radio frequency, ...

The new Thread- and Matter-enabled Aqara Motion and Light Sensor P2 came out Tuesday for use with HomeKit and other smart-home platforms, the company said. “In the rapidly expanding global market for ...