FreeBSD and controlling an alarm via relay

Luiz Otavio O Souza at
Tue Jul 5 01:59:19 UTC 2011

On Jul 4, 2011, at 7:39 AM, Achilleas Mantzios wrote:
> Hello, sorry for the cross-post but i believe this question might seat in both lists.
> I am the guy who had the done the old 1.23.3 zoneminder port some years ago, and i am thinking of installing/testing
> the new 1.24.4 port, submitted by bsam at
> Besides the basic functions, i am thinking of re-using some old techniques by which i controlled 
> the home alarm via a NC/NO circuit (basically it was an enhanced door contact), 
> driven by an old zyXel modem,  which in turn was driven by a small perl program driving the com port, and 
> which was called by a deamon reading zoneminder shared memory info directly.
> That way i could trigger the alarm system getting into alarm state, whenever zoneminder detected motion,
> in a fully controlled and programmatic way.
> Now i am thinking of re-doing this, a little bit more modern, if possible. I was thinking of some relay board
> (instead of the old modem), possibly ethernet controlled (to get rid of all the obsolete com port programming),
> and such. Also i will scrap the old NO/NC solution (circuit embded in the door contact), and i wil use instead a new 
> dedicated wireless transimter i bought (same brand as the alarm system), which is also NC/NO and receives
> two inputs and corresponds to two zones. So i am thinking of assigning 2 cameras as two disctinct zones
> in the alarm system.
> That is the rough idea. What would you guys have to recommend (regarding the relay?). I do not plan to use
> this relay for power/lights on/off and such, at this stage it will function solely to drive the alarm transimtter,
> (which in turn will drigger an alarm to the central alarm control panel)

If you want to go ethernet -> gpio, i think the routerstation (or routerstation pro) is one good option. The routerstation (not the pro version) works with 12v~24v (12v is kind common for alarm systems) and has 7 available GPIO pins (which works as inputs and outputs - you can connect relays, switches, leds, lcds, i2c and spi devices).

GPIO pins can be easily controlled from userland with gpioctl(8) or with a small C program with the appropriate ioctl()s (or even using the led(4) framework).

Please take a look at for more detailed information.

Both boards works _really_ fine with -current.


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