ESP8266 Community Forum

- Mon Jul 30, 2018 11:24 am #77489 Hello,

I have an “old alarm system” (about 15 years), which has wireless motion sensors and wireless siren… (http://www.antifurtologisty.it/S310-22I.htm 1 - I cannot find an english version of it)…

The brand has now been bought by Hager (https://www.hager.com/) and it has since dismissed…

Nothing wrong with the system, it has a cantral with incorporated siren, keypad, and Phone connectors (I can manage the system via phone too - wired to the home phone line)… all the sensor (including an external siren( are wireless)…

I was wondering if it is possible to retrofit the system and make it “smart/connected” so I can see status/manage the system itself with my mobile…

I have done some researches on the system and nothing much could be founded... for now I have found some simple example on how to use dome electrical connections that are in the central system unit:



The only example that make sense to me is EXAMPLE # 3, in order to “read” the system and detect if is is ON or OFF… in this case I would connect somehow Output Relay 2 to the Arduino (someone suggested me a NodeMCU that could talk with a RPi3-openHAB) and the system would know the status of the alarm…

Anyone can help me understand what are the EXAMPLE #1 and #2 for?


I am here trying to look for help and try to understand how to use the existing connection on my alarm system central unit, in order to make the all system "smarter"...

Questions:

1)How do I monitor I/O from Alarm System Central Unit? (what I am guessing is to connect the existing electrical contacts (as per picture OUTPUT relay 1, OUTPUT relay 2 and auto-protect INPUT) to an arduino/nodeMCU device and see what's goign to happen when I arm the alarm system, when I disarm it and when the alarm detect an intrusion... the problem is that I would not have a clue how to get thin info out of the overall system....

2) how can the I/O contacts be smartly used in an automation/smart project?

3) is that true that a NodeMCU would be the best option?

4) which pins should I use in a "standard NodeMCU" ?

I am an absolutely newbie in this world and therefore, please be patience with my silly questions

Thanks All

Ivan

- Mon Aug 13, 2018 4:00 am #77710 I modified an old security panel with an esp8266.

The instructable at https://www.instructables.com/id/Securi ... r-ESP-12F/ might give you some ideas.

However, my case was for a wired alarm unit rather than a wireless one so not directly applicable.

You need to think what smarts you want in your case. The possibilities seem to be
1) Monitoring of on/off status via relay 2
2) Monitoring of alarm status via relay 1
3) Possible expansion of alarm sensors by exploiting self-protection input.

Monitoring of the on/off status and alarm status are fairly straightforward. One can connect the common (c) to 0V on the MCU and say the NC to a GPIO pin. This also needs to be pulled up with say a 10K resistor to the 3.3V on the MCU or you could use the built in internal pull up on GPIO pins (using pin mode INPUT_PULLUP) providing the wiring is kept reasonably short. While the relay output is in its normally closed state then the GPIO pin reads 0 (LOW). If the relay opensit reads high.

The examples using the self protection seem to indicate that it can be used to detect tampering to the wiring to the siren unit. E.g. if the wiring in the example is tampered with (cut through) then the pins between the self-protection pins are also broken and this is detected. If this is the case then there will probably be a default wire link installed between these terminals.

If that is what they are being used for then one can probably use this as a way to expand the system by controlling a NC relay contact into those terminals.

Choice of which GPIO pins to use is pretty free; you just have to match the code to which pins you use. It is best to avoid GPIO0 and15 (D 3D8 on NodeMCU) as this can conflict with start up booting.

NodeMCU is good fro development. You can also use it for deployment but personally I prefer to use ESP-12 modules for that to keep size down if space is tight.

- Thu Oct 29, 2020 7:01 am #89250 This may be of interest. I created a project to add additional ‘smart’ functionality into a thirty year old (1993) but fully functioning (and reliable) alarm system.
https://github.com/blaniosh/alarm/wiki