Here is an ultra simple Arduino Night Alarm project wired around a handful of inexpensive and easily available components. One advantage of using Arduino as a security system is the flexibility!

PIR sensor 18 Articles 2023 Halloween Hackfest: Quoth The Raven, “Caww!” October 31, 2023 by Kristina Panos 5 Comments ...

The actual circuit is just a piece of perfboard, a large, old relay from Sparkfun, and a PIR sensor [Greg] picked up last year. Whenever the PIR detects movement, the Tiny85 activates the fog ...