The CNET home security editors have tested out every major home security system over the years. We haven't listed every single one here, since some, such as AT&T Digital Life, are no longer available.

It also remains one of the most user- and budget-friendly alarm systems you can buy in the home security market ... an optional professional monitoring service called Ring Protect Plus for ...

Cheap 120db 12v peizo siren - $3.50 Arduino nano clone - $2.50 Power mosfet - $1 PIR motion sensor - $2 Perf board $1 The arduino in there to provide a bit of smarts during power on and alarm states.