Physical keypad for alarm

Hi everyone. I am currently implementing at home an alarm system to interface with home assistant, and I have chosen to rely on then using wired sensors. I will then have the sensors that will communicate with the konnected control unit that will transmit the states to Home Assistant. I’m using the alarm_control_panel with mqtt.
my question is: if you want to use a physical keypad to be mounted on the wall, how can I do it? the need would be that it detectes the status of the alarm (away, home, disarmed) from Home Assistant, and that it recognized the codes entered and then communicated the activation of the mode or deactivation to Home Assistant. is there any way? thank you

I dislike as it’s wifi based and to me this is a significant weakness for alarm and security duties. It’s too bad it didn’t have an ethernet port or I would have purchased already…

what would you suggest as an alternative? I’m renovating the whole house, so I have a reduced budget, I find konnected an excellent low-cost option. it obviously depends on what you want to protect, not having Picasso at home a type of low-cost alarm for me would be great, even wired so as to lower the cost of wireless devices and have a choice not bound to the manufacturer

An rpi with the sensors connected to gpio pins. A bit of code to tie in to mqtt.

Yes, that works well. You can run HA on it if you like; or if not convenient you can use hasslink to join the to your primary.

Anyone know of a WIRED physical keypad for an alarm? Ideally one that talks MQTT…my zigbee keypad just randomly flaked out on me which I just can’t handle for an application like this. connected to an esp32 with ethernet and control it all with esphome.

This Aliexpress link is broken. What is the name of the device?

Sorry three years later, I have no idea.

Possibly something like this

Also see Matrix keypad — ESPHome

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Thanks. It was a long shot … I’m glad you are still around!

I know it’s an old thread, but in case anyone else is still asking the same questions (as I was when I found it)…

  1. I am also unimpressed by Konnected, though I do believe they have an Ethernet option these days. Still I think it is expensive for what is essentially a kit of parts without an enclosure, based on ESPHome. You might as well make your own ESPHome solution.
    I am doing just that. My board will replace the PCB in an existing Scantronic 9651 box, so the wiring can be just transferred across. It will have an ESP32, Ethernet module, and an I/O expander, so up to 16 zones / anti-tampers and two or more outputs are easy and works well without the keypad.
    Even if you do not already have a Scantronic alarm system, you could do worse than pick up a second-hand box on eBay for a tenner.

  2. I just started a new project to reverse-engineer the Scantronic 9940 keypad, replicate the comms protocol and make it into an ESPHome Custom Component. The keypad could then be part of solution 1, or be used stand-alone.
    Even if you do not already have a Scantronic keypad, you could do worse than pick up a second-hand one on eBay for a tenner. However, do not rush out and buy one on the assumption that I will succeed – it’s a challenging project and has a long way to go yet.

Scantronic 9651 Hardwired Alarm Replacement Board
Scantronic 9940 Keypad Interface

Incredible timing - that we both pick up on a three year old thread only a fortnight apart. Was just looking into you notes, you’ve really given this some solid thought. About to turn in for the night, but eager to have a good read of your thoughts tomorrow!

Thanks for your interest. Work is ongoing.

With an oscilloscope I can see that it is a serial protocol a little like I2C but without the ACK bit and running at just 2kHz with Vcc voltage levels – nominally 12V but more like 14V on my sample alarm controller using the original power supply (that makes sense because there is a 12V backup battery, which would go up to about 13.8V).

I am building two line drivers with P82B96 bus interface chips following Philips application note AN460 figs 4 and 7. Either one can be used in the final solution.

To reverse engineer the protocol, I plan to connect them back to back between the sample control and keypad. The one with optocouplers (fig 4) separates Tx and Rx so I can see traffic in both directions. I will then use four channels of a cheap logic analyser to get more info on the protocol in both directions. I do not know yet, for example, whether the master or the slave clocks responses.

It could take a while, but watch this space and project KELLY on my GitHub pages!
… and please share any info you find :slight_smile:

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Just ordered a few WT32-ETH01 boards and a bunch of components to give it a crack… From the look of things you’re light years ahead of me, but if anything pops up I’ll def pass it along. Absolutely following on Git… Hope you at least got yourself a half decent coffee! :wink:

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Caffeine is my main fuel supply. Thanks. :+1: :crazy_face:

Are you building a full Scantronic 9651 hardwired alarm replacement system? If so, check out my project HARVIE in which I tried several solutions, including a successful one based on the WT32-EH01 (solution 2).
However, to integrate the keypad (project KELLY) onto the same board, more usable I/O pins will be needed, so I am now going for solution 6, which uses an EPS32-WROOM combined with a USR-ES1 Ethernet module.