If you’re looking for a basic—extremely basic—DIY security system, take a look at X-Sense. The company, best known for its range of smoke detectors, offers a bare-bones system that works fairly well and costs next to nothing.
The X-Sense Home Security Kit is available in two versions: There’s the $130, 5-piece kit reviewed here, which includes a hub, motion sensor, two door/window sensors, and a remote-control key fob. An extra $40 will get you X-Sense’s 8-piece kit, which adds an additional motion sensor and two more door/window sensors. The only additional sensor type that works with the system is its Wi-Fi Smoke Detector, which is sold separately.