The sensors in question are from an old GM Interlogix security system. The sensors themselves sit on doors or windows. They use magnets and a reed switch to sense if the door or window is opened.

But if you live in a typically dry area, this motion sensor light could be a good fit. Although this light is hardwired, the Ring Floodlight is anything but old school. Download the Ring app and ...

this DIY motion trigger for a DSLR is a quick and easy build, and probably loads more fun. The BOM on [Jeremy S Cook]’s build is extremely short – just a PIR sensor and an optoisolator ...

Prior knowledge needed: ECEA 5340 Sensors and Sensor Circuit Design and ECEA 5341 Motors and Motor Control Circuits. Understand how to specify the proper pressure, force, strain, position, motion, ...