Use gpiozero to read the state of the magnetic reed sensors on the doors and control the doors via relays connected to GPIO pins
Use paho-mqtt to publish MQTT status messages and subscribe to command messages
The door contacts are GE Overhead Panel Door Magnetic Contact
The relay board is found on eBay. Search for 4-Channel Optic-Isolated Relay Module H/L Trigger 3.3V-5V Arduino / Raspberry PI
topic = stat/garage/NAME
payload = {"state": "STATE"}
topic = cmnd/garage/NAME
payload = open or close
sensor garage_north:
- platform: mqtt
name: "Garage North"
state_topic: "stat/garage/north"
value_template: "{{ value_json.state }}"
cover garage_north:
- platform: mqtt
name: "Garage North"
device_class: garage
state_topic: "stat/garage/north"
command_topic: "cmnd/garage/north"
payload_open: "OPEN"
payload_close: "CLOSE"
state_closed: '{"state": "closed"}'
state_open: '{"state": "open"}'
qos: 1
retain: false