Connecting the Raspberry Pi to the real world
Did I overlook it, what I miss is the wiring diagram of your interface. My special interest is with the digital I/O. Thank youHans
You didn't miss it. I actually never created a complete drawing - just pieces. If you go farther back in the blog you should find most of the sections covered separately. There are some good tutorials on the web, such as this one:http://elinux.org/RPi_Tutorial_Easy_GPIO_Hardware_%26_Software
I have a piface running a similar project and my door switches work great but my motion sensors are triggering every few seconds... I left the inline resistor there from the original alarm panel. Any ideas why my sensors might be going bonkers? The LED on the front of them seems to respond to motion correctly.
First I would verify that they really are triggering when they shouldn't. I did this by connecting the one I had trouble with to a multimeter that had a tone output option when a circuit was closed. It's easy enough to create something to do the same thing.If they are triggering, but the duration of the trigger is very short, then you could filter that out in software by requiring the trigger to last some minimum time before considering it actually triggered. If the false triggers are actually just transient spikes from somewhere, then this filtering should work. I had to do this with the sensor at the end of my drive way. It has over 350 feet of unshielded cable run outdoors, so it isn't surprising that it picks up some noise.
Very nice posting, thank you. Have a look at projects.privateeyepi.com/home on how you can hook up your alarm system to a an alerting system and web based dashboard control.