Home Alarm PIR signal question

Thread Starter

Zaplady

Joined Oct 17, 2012
11
The pir is designed for a specific panel that uses positive loop detection, the transistor pulls the nc terminal to ground via a 100 ohm resistor when no detection is present, then when it detects an heat source like a person, it removes the ground and goes open circuit.
Thanks for this Dodgydave. I am assuming that it is possible to detect this happening on NC at the alarm box. Would it be possible for someone to explain how I could detect this on the wires coming from the NC terminals remotely with a micro controller or something similar?
Thanks again for all the help so far.
 

Dodgydave

Joined Jun 22, 2012
9,911
Yes, just put a 100k resistor from the NC terminal to the micro 5v supply, and take the NC terminal to the micro sense pin, common both negative supplies together, so when the pir detects the micro pin will go high.


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Thread Starter

Zaplady

Joined Oct 17, 2012
11
Thank you very much Dodgydave . My problem is solved.
I have drawn up a fritzing sketch for the next person who looks this up on the internet.
Reading the output of a Petite 101 using an Arduino

Thanks again to everyone who gave up their time to read my post and think about my problem. It is much appreciated.
 
Great thanks this looks to be just what I need , I have been having the same issues with the a similar model of alarm - basically PIRs are in place from an old ALarm and I want to reuse them via Arduino rather than installing new 'smart' ones
 
Thank you very much Dodgydave . My problem is solved.
I have drawn up a fritzing sketch for the next person who looks this up on the internet.
Reading the output of a Petite 101 using an Arduino

Thanks again to everyone who gave up their time to read my post and think about my problem. It is much appreciated.

THanks for posting this, it looks exactly what I want but have been unable to get it operational - I am just not seeing the voltage change for the PIR motion. If I short it I can see that or if I break the circuit but not the PIR - have tested against multiple PIR and I dont think they are broken because they pick up my movement and light the LED - I jus dont see anything on arduino voltage change,

Can you offer any advice ?
 
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