My home alarm provider have retired all products they made before 2018 in favor of their new lineup. They now push hard for "upgrading" to their new system, to which of course no sensors of previous generation are compatible, so you have to buy everything again.
The new system also comes with a new, less buggy app. The previous app wasn't bug free even when they stopped updating it. So you would need to spend hundreds of dollars to upgrade all sensors and panels just to get a bug free app.
Or would you?
When I purchased the system in 2016, they knew what a mess their app was, so they sent two remotes for free.
Now in 2020, it is time to solve the problem of a buggy app by making our own.
It is very simple and it always works instantly. Three settings corresponding to 3 buttons of the remote.
I opened one of the remotes and put an ESP8266 Wemos D1 mini's 3v supply to it. Then I soldered optorelays on the button pads on the remote to be controlled by the D1. I put everything in a old tea jar, which happened to have a glass top. The diameter of the glass was almost the same as a Neopixel wheel, so I glued that underneath the glass for status indication etc.
I spray painted the jar white, and the lid is now glued to the base because of the paint :( so I can't get any pictures of the hookup.
The setup remembers the last command sent to it, and the apps (Wife also uses the app on her phone) therefore know the current alarm status. Everything is sent and saved over Firebase.