Connect PIR-700 sensor to RPI2

[blackout08]

I have an existing alarm system in my house that never worked since we moved in. I wanted to connect all the door sensors and 2 motion sensors to a RPI.

To start, I grabbed one motion sensor, a PIR-700, which has 4 wires connected as follows (images attached):
1. Black - Port 5
2. Red - Port 6
3. Green - Port 18
4. Yellow - Port 19

https://imgur.com/huNLO7Y
https://imgur.com/klsdla3

I assume I can connect the ground and power (5V) wires to the sensor from the rpi but I am not sure what to do for the green and yellow.

Any help would be appreciated.

[pcmanbob]

Hi.

No you can't just connect 5V to your alarm panel from the pi,

The alarm panel is designed to work at nominal 12V, so the pir sensors would not work at 5V,
the door switches will have termination resistors again designed for 12V operation.

To use the pir sensors you would need to provide 12V DC to the terminals +/- and then use the N/C terminals like any other switch connected to your pi.

To use the door switch wiring is complicated due to the long wiring runs, you would probably need to remove the termination resistors and then again use the switches like any other switch connected to the pi, but due to the long cable runs they may not work correctly at 3.3v.

So you would need to run them at a higher voltage and have an interface circuit at the pi gpio as the gpio can't have any voltage higher than 3.3V connected to it.

You may be better using 12V for all the existing alarm wiring/pir's and then have opto isolators between the pi gpio and the wiring to interface at the correct voltages.

[blackout08]

Hi.

No you can't just connect 5V to your alarm panel from the pi,

The alarm panel is designed to work at nominal 12V, so the pir sensors would not work at 5V,
the door switches will have termination resistors again designed for 12V operation.

To use the pir sensors you would need to provide 12V DC to the terminals +/- and then use the N/C terminals like any other switch connected to your pi.

To use the door switch wiring is complicated due to the long wiring runs, you would probably need to remove the termination resistors and then again use the switches like any other switch connected to the pi, but due to the long cable runs they may not work correctly at 3.3v.

So you would need to run them at a higher voltage and have an interface circuit at the pi gpio as the gpio can't have any voltage higher than 3.3V connected to it.

You may be better using 12V for all the existing alarm wiring/pir's and then have opto isolators between the pi gpio and the wiring to interface at the correct voltages.

Thanks pcmanbob. I noticed my error in my ways last night when I realized what I was doing. Much appreciated.