Too Long; Didn't Read
A DevOps engineer who loves automation, programming and electronics decided to build a sensor for the front door. He wanted to be able to detect whether the door is open or closed. After a heavy research session that left my head fuzzy and spinning, I finally had enough information to start planning how the design would work in practice. The basic door and window sensors use a reed switch and act just like a light switch, except these switches use magnets to control whether they are on or off rather than using a human finger. For my system I decided that a normally closed sensor would be the better choice.