[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 the microcontroller era today, Arduino is more than just a tool to accomplish hobby tasks. There is actually a close relationship between microcontroller technology and home security, since you can ...

Moderately priced Passive Infrared PIR Sensor modules are now widely available. By using these readymade and pre-configured PIR sensors, even an average electronics hobbyist can construct his/her own ...

(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. PIR ...