[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 ...

Tired of spending countless hours manually cleaning your pool? You're not alone. The tedious task of pool maintenance has long been a source of frustration for homeowners, but modern technology has ...