A friend of mine whom uses Vera and some other home automation program told me about this hardware called alarm decoder. Supposedly it allows anyone with a honeywell or ademco alarm systems. I have an old school protection one alarm system in my home I would love to be able to utilize if possible through HA.
I am using it. I got it to work in HA for me, as a rest sensor (for what I need it). It is unfortunate that HA does not have an integration for this device as they do for Envisalink. If this is a deal breaker for you, consider other options for example I got it to work perfectly with OpenHab.
I am using the AD2PI version of the device.
I am using AD2PI on a pi zero, connecting to my network, and accessing it over the network from my Home Assistant instance on my Docker. It has been stable as hell for months without so much as a reboot.
The Alarm decoder GIThub site hasn’t been updated in 4 years and the Nutech web site has an expired cert and doesn’t show the hardware product any more. Looks like it’s no longer an option.