Dsc Serial Protocol
The IT-100 communicates with the application with a serial cable from an on-board RS-232 interface. DSC recommends. 2.4 Command Protocol.
I am trying to understand this protocol that my DSC 1555 alarm uses between the base and the keypad, but issue is its propriatary of some sorts. There was another thread about it on this forums but it ended prematurely with the guy just checking one bit for stay or away mode.
From what I know about this protcol so far the clock line runs at 1kHz with 50% duty and oddly enough only does so for 41.6ms then it stays high for 5.4ms and starts all over again. The data line seems to transistion on either the falling or rising edge of the clock (or in the middle), which led Kortuk of chiphacker.com to belive that it is NRZ encoding which I'm not sure of yet but here are some OLS dumps of the data and clock lines hopefully with teamwork we can figure this out.
I'm pretty sure the data is the same as whats listed in the PC5401 pdf below just sent via some weird protocol, all I really need help with is figuring out whats a 1 and whats a 0. From there I'm confident I can figure out the rest. Thanks for your time :D
0 is the Data line, 1 is the Clock
Dsc Alarm Serial Protocol
DSC OLS Dump
ECP Patent
PC5401 Dev-PDF
Previous AVRFreaks Thread
Dsc Rs232 Protocol
When [Doug] moved into his new house, he found an old alarm panel set up — but it had no monitoring service any more. Not wanting to pay a monthly fee to have it setup, he decided to try interfacing an Arduino with the system in order to push events to the net!
The cool thing is he was actually inspired by another similar project we shared on Hackaday a few years ago entitled Bending a Home Security Control Panel to Your Will. But that project only showed you how to interface the Arduino with the keypad — [Doug] went the extra mile and interfaced directly with the control board for more features.
He’s using an Arduino Uno and an Ethernet breakout board to hook it up to the network. This allows him to send text messages to himself when the alarm system is armed, disarmed, or triggered. All the code is available on GitHub in case you also have a DSC 1550 alarm system.
Dsc Serial Protocol
It’s a pretty slick hack, so don’t forget to check out the video after the break.