How it works: When something triggers the sensor, the Arduino records that moment as triggerTime in Line 23, and compares it with the current time based on conditions in lines 26, 29, and 34.

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 ...

A passive infrared motion sensor is used to detect the motion of the user’s hand in front of the clock. While all kinds of clocks and clock radios are available out there, few are motion activated.

You'll definitely need some gear for it—the Arduino for one, but also a PIR motion sensor, not to mention the (cleaned and rinsed!) Raid Power Sprayer motorized spray bottle.

Therefore, the 9V signal is then lowered once more using a voltage divider circuit. When the PIR sensor is triggered, it activates the timer circuit. The timer circuit is driven by a 555 timer.

Makers and developers looking for a motion sensor Arduino Shield, are sure to be interested in this new ICU-Duino which has been created by Patrick Thomas Mitchell based in Ottawa, Canada.

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 ...