For reusing the ADT sensors that's a bit complicated depending on what was installed, when, etc. I'm going to assume it's a home alarm, if not you can probably ignore me! ๐
If all the sensors are hardwired you could maybe go with Konnected.
If they are wireless and it's older it might be a Honeywell Vista series alarm, ADT re-branded them as SafeWatch Pro as far as I am aware. Vista series alarms have 2 options that are available that I am aware of. 1 is an EnvisaLink 4 by Eyez On and the other is a DIY ESPHome based option called esphome-vistaECP. There is also Alarm Decoder, but they seem kinda dead now and all their stuff is sold out.
For reusing the ADT sensors that's a bit complicated depending on what was installed, when, etc. I'm going to assume it's a home alarm, if not you can probably ignore me! ๐
If all the sensors are hardwired you could maybe go with Konnected.
If they are wireless and it's older it might be a Honeywell Vista series alarm, ADT re-branded them as SafeWatch Pro as far as I am aware. Vista series alarms have 2 options that are available that I am aware of. 1 is an EnvisaLink 4 by Eyez On and the other is a DIY ESPHome based option called esphome-vistaECP. There is also Alarm Decoder, but they seem kinda dead now and all their stuff is sold out.
If it's a rebranded DSC PowerSeries the EnvisaLink 4 also works on it and the same person who made the other ESPHome project for Vista alarms has one for the DSC PowerSeries called esphome-DSCKeyBus
Aside from those I am unsure what all ADT has sold/rebranded over the years. Some stuff appears to maybe be Z-Wave, but unsure about all of it?
I am using esphome-vistaECP personally and once I got it setup it's been working flawlessly!