Arduino interface with First Alert Professional FA130CP

Goal: I want to use my wishield with an arduino to ultimately have an internet enabled alarm interface.

I have a First Alert Professional FA130CP controller installed in my house. I have 1 existing keypad. I purchased a new one to basically take apart and look at the hardware used for communication between the controller and the keypad unit. I haven’t had a chance to take it apart yet. I know that there are only 4 wires, Data In, Data Out, +12V and Ground. I suspect that the communication is simple RS232. At this point I can’t find any information on the communication protocol used between the keypad and the controller. Does anyone have any experience with how an alarm controller communicates with the keypad or any suggestions on how i should go about determining the communication protocols?

Attached are the User’s Manual and Installation Manual for the FA130CP. (It has several alarm reporting protocols listed, SESCOA/Radionics, Ademco Low Speed etc but I think that is referring to the communication over the modem to the alarm monitoring service.)

FA130CP Users Manual.pdf (884 KB)

FA130CP v2 Installation Manual.pdf (730 KB)

FA560KP Alpha Installation Guide.pdf (41.7 KB)

Start with a DMM measuring the voltages, then a scope looking at the signal ...

First Alert is basically Ademco. I am going to try and do the same thing with my Ademco alarm system, but haven't had time to wire up the circuit and do some testing. In a nutshell, the communication protocol is patented and is based on some sort of RS232. Check this link out for a bunch of information and help. What you want to do is NOT simple. The arduino, while very, very cool, is not going to help at all with this. The circuit is separate and you will need to write code such as VB.Net or C++ or the like. Anyway, here is the link.

http://www.diysecurityforum.com/index.php?topic=10480.0#top

Good luck!

Tom