Experience interfacing old alarm and Piface?

Post Reply
User avatar
EdddieN
Posts: 132
Joined: Wednesday 16 November 2016 12:31
Target OS: Raspberry Pi
Domoticz version: 3.5877
Location: Scotland
Contact:

Experience interfacing old alarm and Piface?

Post by EdddieN » Monday 03 April 2017 13:34

Hello there

I'm trying to use the PIR detector from my old alarm to use them as motion detectors on the Piface. I have measured the voltages and it looks like 6Vdc so probably should be ok.

Has anyone done something similar before? Just thinking whether I need a signal splitter or I may just join the signals.

Any crazy feedback is welcome :D

Jan Jansen
Posts: 140
Joined: Wednesday 30 April 2014 20:27
Target OS: Raspberry Pi
Domoticz version: Stable
Location: The Netherlands
Contact:

Re: Experience interfacing old alarm and Piface?

Post by Jan Jansen » Monday 03 April 2017 17:33

The maximum voltage on the input pins is 3.3V. You can use a small circuit like download/file.php?id=188 to protect your piface.

User avatar
EdddieN
Posts: 132
Joined: Wednesday 16 November 2016 12:31
Target OS: Raspberry Pi
Domoticz version: 3.5877
Location: Scotland
Contact:

Re: Experience interfacing old alarm and Piface?

Post by EdddieN » Monday 03 April 2017 17:50

Thank you!

I did look for documentation re the Piface for max input, all I could see is 5Vdc with optional pull ups to 3.3Vdc

User avatar
EdddieN
Posts: 132
Joined: Wednesday 16 November 2016 12:31
Target OS: Raspberry Pi
Domoticz version: 3.5877
Location: Scotland
Contact:

Re: Experience interfacing old alarm and Piface?

Post by EdddieN » Monday 03 April 2017 23:04

Ok, for my setup it looks like I need to put the inputs in tristate mode (external pull up).

Haven read the Piface.conf documentation... there's nothing that mentioned it.

Is there any way to do this?
With WiringPi it was possible to use tristate

Post Reply

Who is online

Users browsing this forum: No registered users and 1 guest