Reuse old house alarm PIRs for new security alarm

Thread Starter


Joined Feb 28, 2018
I need some help please ! The house already has a number of PIRs wired in throughout the house, these all work fine but I want to make this a 'smarter' arrangement and access the PIR outputs via an arduino board - that I can subsequently link into a home automation alarm set up I have.

I am not an electronics expert but have done quite a bit of research including following this thread and setting up the same circuit

but having done that my problem is I am no detecting the PIR triggered motion - ie when the NC circuit goes open. If I physically break that circuit I see the output go high but I am not seeing anything or the PIR triggered motion.

Is my problem linked to the properties listed here nc circuit pir sensor&f=false

In that I get high for a break in circuit , I get low for a short, but I am not seeing the impact of the PIR triggered change ?