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!

Want to set up a home security system, but don’t want to pay a monthly fee to a security company? Techradar has a detailed do-it-yourself project for a connected alert system using Raspberry Pi.

TK has combined a PIR with an Arduino to create a smart safety light for the house or workshop. Follow along as this gets built out into a more extensive project.