Apart from this device being able to connect via Home Assistant to provide all the intelligence, what I really like is that it just attaches to most existing dumb garage door openers. Most door openers have two connectors intended to wire to a switch on the wall to open or close the door (many installations never have such a wall switch fitted, but usually the openers have that ability already). If that fails, you can still connect this directly to a spare remote control.
The other clever thing comes in with the positioning of the device so that both the car is below it, and the garage door when it is in the fully open position. The ultrasonic sensors are able to measure the distance to the floor, the car roof, or the garage door when it is open. That distance then indicates accordingly whether the garage is empty of the car (you are out and the door is closed), whether the car is inside and the door is closed, or whether the door is open.
It seems the easy way to use this remotely would be to use OpenGarage’s cloud service with the token, but means depending on that service being there. The other way is to rather connect and manage it from Home Assistant running on your home network, which will give you full control over it – this is a little more complicated but can also offer you even more automation based functionality.
The device costs about US$50, but wait, there is more… It could also be repurposed quite easily for doing similar things with say water tank levels, where the relay could activate or deactivate a pump for example. So, don’t think of this as only for garage doors.