I wanted a door lock sensor so that i can see if the door is locked. Our door has three bolts and two of them come out of the door and hook into the frame:
This is known as a ‘driepuntssluiting’ in the netherlands.
I wanted to make use of the fact that the hook moves downwards when the door is locked.
I placed two combined dip switches in the frame and connected them to a low power MySensors compatible switch node.
Parts i used:
I glued together two switches and added a small plastic plate to the levers. I placed them inside the frame like this:
The switch node is placed on the inside of the frame like this:
I connected the node to my MySensors gateway and if the state of the lock chenges, a MQTT message is sent to Mosquitto and it’s picked up from thre by Home assistant.
The node runs a couple of weeks now and it’s pretty stable. It works very reliable.