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 ...

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 ...

Many close-proximity motion detectors use the classic, widely available passive-infrared (PIR) approach, which is effective but has limited sensitivity and adjustability, and can’t “see” through ...