Retrofitting alarm system to detect when siren/alarm sounds

Hi guys, wondering if anyone’s done his before - I’m thinking this is a fairly simple premise - I just need to know when my alarm sounds when I’m not home so I don’t need to rely on subscription services or neighbours.

Basically, I’m thinking that something will need to be wired in parallel for the wires which connect to the siren (assuming that it sends a charge when motion is detected and no key is pressed). Device detects connected circuit, sends packet (bluetooth? http? 433Mhz?) to OH bus and I simply script a rule to send an email or similar.

Ideas welcome :slight_smile:

Edit: I think z-wave binary sensors may be an interesting way to approach this.

That is exactly one of the use cases for this nice little device. But keep in mind they need to be mains powered, even if the manual states you can operate them via battery (9V battery was drained empty after 2 days in my case …)

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The Fibaro Universal Sensor is designed exactly for this purpose. It will run off 12VDC which most alarm systems run on, and can be wired in to parasitically monitor two sensors, i.e. siren and a PIR. I have two in my alarm panel monitoring the various PIRs around my place.

Can also add up to four DS18B20 one wrote temperature sensors to each one for temp monitoring.

Great little devices!

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thanks - I was looking at the Fibaro and as you state it has 2 sensors + 4 temp

when you say that - wouldn’t you still need 2x 12VDC power supplied if you’re putting in 2 Universal Sensors into the box? I don’t think you can piggy back the DC sources can you?