[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 ...

In this tutorial we will use a Passive Infra-Red (PIR) sensor as an input to trigger a LED. A PIR sensor works by detecting heat as an object passes by it. Plug the micro: bit into the GPIO shield.

The PIR motion sensor consists of 3 pins-VCC, GND, and the Data Output Pin. VCC is the power pin of the module. Out is the data Output pin of the module.it goes high when motion is detected. GND is ...

Living objects with a body temperature above 0°C emit heat as infrared radiation, also known as thermal radiation, which is invisible to the human eye. PIR sensors, designed for this purpose, can ...