[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 ...

An automatic toll gate system using Arduino revolutionises traditional toll collection by eliminating manual intervention.

I recently had to build an infrared close proximity sensor that could tell if something was dropped in a parcel delivery drop box. After some searching, I ended up using a microcontroller and a piece ...