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!

Present consists of just a PIR sensor and Arduino in a 3D printed enclosure to snap onto your monitor.

The code is an Arduino project for the Digispark Attiny85 to turn on a light source when the PIR sensor detects something. Note that after powering the PIR sensor module, it needs about 10 to 60 ...

The important bit on this wireless sensor, the PIR sensor, connects with three pins – power, ground, and out. When the PIR sensor sees something it transmits a code the base station where the ...