The best sensor you can use to detect an intrusion is the Passive Infrared (PIR) Sensor. The PIR Sensor detects the motion of a human body by the change in surrounding ambient temperature when a human ...

While PIR sensors can be used with Arduino and other microcontroller boards, those best-suited for hobby use are smart enough to perform simple tasks without any programming.

Present consists of just a PIR sensor and Arduino in a 3D printed enclosure to snap onto your monitor. ... His goal was to use PIR sensors to detect when a person is moving nearby.

The sensor shown here is essentially two plates mounted side-by-side, attached to an Arduino Nano using the Capacitor library which uses just two pins, one digital and one analog.