secplus VS elkm1

For Chamberlain brands [0] there is some research that shows that their rolling code system (Security+ and Security+ 2.0) is quite easy to decode/decrypt [1]. This feature is supported in the flipper firmware, but is restricted (you can't create a custom remote, only clone is supported) without custom firmware. However, I'm sure you could decode a raw capture file if needed in a pinch.

[0] https://chamberlaingroup.com/our-brands

[1] https://github.com/argilo/secplus

A gentle reminder that the Security+ and Security+ 2.0 RF protocols have been reverse engineered (https://github.com/argilo/secplus). While they are not the most secure thing in the world, you can build a custom RF transmitter (remote) that is network connected.

Having done some research into Chamberlain's products, I don't recommend anyone to use them if they have the choice.

This is not an attempt to break the RF Security+ encryption that this, and other garage doors utilize. That has already happened. https://github.com/argilo/secplus

Here is the rolling code project: https://github.com/argilo/secplus

ratgdo looks really nice! I've been controlling my garage door via dry contact on my Elk security system [1] and monitoring the door status via a separate rolling door reed sensor. [2] But from following the ratgdo link, I learned that my "Security+ 1.0" garage door opener has a RS-232 interface with a protocol that will tell you about door status and obstructions. That's better!

I just clicked the buy link on the ratgdo thing to support the nice, well-documented open-source [3] project. In truth though I have the right hardware sitting around here already, so I might just use that depending on how long the "back ordered" status lasts...

[1] There's a Home Assistant integration for the Elk M1 Gold with some Python library; I also have my own WIP Rust library for interacting with it here: <https://github.com/scottlamb/elkm1>

[2] something like this one: https://www.amazon.com/Gebildet-Security-Rolling-Magnetic-Ap...

[3] docs at <https://paulwieland.github.io/ratgdo/> but the actual code is in a separate repo at <https://github.com/ratgdo/esphome-ratgdo>

I own one. It's good but not perfect. Some complaints:

* The protocol has a lot of oddities. E.g. it sends out spurious "fully armed" messages when it's actually in the process of arming [1] so a good integration has to debounce these. (The one built into Home Assistant doesn't, last I checked. It just reports weird states. iirc it will even say "arming" long after the panel is fully armed.) The command to disarm remotely only works if the user whose code is supplied is configured in a particular way. (Can't find the reference for this right now.)

* The remote programming tool is a flaky VB.NET app. The protocol for this part isn't documented, although I've reverse-engineered part of it.

fwiw, I have a work-in-progress Rust crate for talking with the Elk. It can be used as an alternate Home Assistant integration via MQTT. [2]

I can definitely see the appeal of rolling your own. One problem though is that I think when talking to an alarm company, the panel is supposed to be certified in some way, which would be a significant barrier for a hobbyist design.

[1] https://www.elkproducts.com/forums/topic/spurious-armed-full...

[2] https://github.com/scottlamb/elkm1