This voltage can be read by an Arduino digital input and then the Arduino can act upon it. The PIR Motion Sensor on the left is made by Parallax and sold by Radio Shack. The one on the right comes ...

It’s a fairly simple project, too: just hook an Arduino Uno up to a motion sensor and an electronic switch called a relay, then plug in your fan, and you’re good to go. If that sounds ...

All you need is an Arduino, a motion sensor, a few wires and headers, and the code provided at the site below. Hit the link to see step-by-step instructions on how to put it together.

[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 ...