I would like to connect an Activ8 PIR sensor (http://www.responseelectronics.com/downloads/13649193548IR110_Activ8_DT_eng.pdf) to my PiFace inputs.
I'm powering the PIR sesnor from an externalk 12v supply. This powers the sesnor and the relay coil. The PIR has a normally closed relay, which is opened when motion is sensed. I managed to get this working (without the piFace board) just checking for an input_value on GPIO pin 12 and using the 3v output directly from the Pi to power the circuit. I'd like to move this to the piFace using the inputs on the piFace.
How would I do this? I assume this is a similar pattern to this one https://www.element14.com/community/people/ge0rgej/blog/2013/09/08/5--piface-digital-emulator . But it's not clear to me how to power the switched realy circuit ito the sensor and how that circuit should be cxonnected to the input ports inorder to detect when the circuit is open using digital_read(0) in my python code.
Any help appreciated.
Many thanks