This project is designed to allow you to connect an Arduino-like device to your Honeywell (Ademco) security panel and "listen in" for key events. This project is an implemenation of reverse engineering the Ademco ECP keypad bus.
Web based front-end at: https://github.com/TANC-security/
YT video playlist: https://www.youtube.com/playlist?list=PLd8PQg3ICYP5eQcQP\_Dx9Q2uO97RlXmbC