Intercept alarm pir signal via esp32

Hi all,

Apologies if this has been asked before, but I’ve not found it when I searched.

Would anyone have tried to capture triggers from a hardwired pir currently attached to a house alarm?

Currently I have a fibaro universal sensor attached, which was connected to my old Vera plus, which I no longer use. I’ve not been able to connect this to home assistant, so looking at easier options, for monitoring the pics.

I’m not looking to automate the alarm in total, just monitor the pirs, at this point.


I use Konnected Pro to monitor each circuit connected to my manual alarm system. The circuits are wired PIRs and wired door sensors. Since Konnected is an ESP32 it wouldn’t surprise you to learn that there are quite a few threads on DIY options using ESP32.

First you need to work out how the PIR is powered and wired for detected state. Following is first thread that comes up when I do a search

Thanks Julian,

I’m ok, I think with the monitoring, I’m looking for guidance with the physical connections.

The pir currently has 12v feed, which I’m thinking of putting through a wago block, to connect all 12v feeds. It then has the trigger wire, which I’m thinking of feeding the gpio connector. I’m wondering if I need a trigger port too, to feed a positive signal through to the alarm box.

I came across a similar post which looked similar, but they omit how they connected it all up.


Perfect. It is what happens in your old system. BUT read specifications of each device to check that is the correct voltage

What is the voltage? GPIO is limited to 3.3v. Do you have a multimeter?

What I did was leave the wires in place on the alarm system and connected into the relevant circuit directly. That way I am monitoring the triggers at the same time as the alarm system. When you say “port” I am not sure I understand what you mean.

I think you need to tap into the other threads as there people are at the coalface of alarm systems.