If you’ve always wanted to try to build an Arduino project, this may be a great way to start. Matt Williamson built a tiny, Arduino-based motion sensor that will SMS you when something moves by your ...

We’re still not sure exactly how [connornishijima]’s motion detector works, though many readers offered plausible explanations in the comments the last time we covered it. It works well enough, though ...

Let me introduce another simple microcontroller-based do-it-yourself circuit that detects motion and excites a light source in a flash. The “snooper” here is an ordinary passive infrared (PIR) motion ...