I’ve been looking for something like this for a while, as there are many interesting automations I could do with it, but haven’t managed to find any reasonable solutions without a lot of DIY.
I’ll describe one such automation and how this would solve it for context.
I manually open/close my garage door quite frequently. I would like to detect “vehicle has left the garage” and automatically close the door when that occurs.
How this product would work:
I would position a retroreflective patch about 2 ft off the ground near the entrance to my garage. The dual IR emitter/sensors would be positioned on the other side, with 1 or 2 inches of distance between the two sensors horizontally.
The sensor would detect a break in the first beam, then the second beam when the front of the car moves through the door. The sensor would detect a restoration of the first beam, then the second beam when the rear of the car moves through the door.
Based on those events, my home automation system can determine (1) an object passed through the door, (2) the direction the object passed through the door, and (3) the object did not reverse partway through passing.
Q&A:
Q: Why two sensors over one?
A: I want the additional information provided about direction two sensors can provide
Q: Why Retroreflectors
A: This prevents the need to have a power source on both sides of the connection. This would not work well as a battery powered solution due to continuous consumption, so running only a single power brick is appreciated.
This is a very interesting idea… reminds me of some RFID work I did in the past with directional readers.
I can see a lot of uses if its accuracy is adequate - occupancy counting / tracking, etc.
[The RFID project I worked on (over 20 years ago) was for patient elopement detection and equipment tracking/loss prevention. It started with ‘where are all the IV poles’? ]
Most of my house is ZWave devices (20 of them being Zooz), which is my preference. I would not be opposed to something based on other local protocols like ESPHome, Zigbee, or Thread.
Battery powered would be great, but, I think the break beam consumes too much energy for battery. So this would probably have to be line powered.
So I just did almost this exact same thing. Currently, the garage door is automated with a ZEN-17 device. It can “press the button” to open or close the garage door, and also has a circuit attached to a contact switch so the HA software knows if the door is opened or closed, all connected to a HA system..
When leaving the house, the HA software opens the garage door and after a set time, automatically closes it as well, unless I’m literally leaving the garage at that exact moment, when the door’s safety sensors kick in, stops the closing action, and opens the garage door.
But what I WANTED to happen was to have the door actually close after I actually LEAVE the garage. So ordered a pair of IR sensors from Amazon and connected it to the Zen-17 to the 2nd sensor input. From there, back in the HA software, I set up a trigger to close the door once the sensor is turned ‘on’. That trigger is normally not enabled… and only becomes enabled when I actually leave the house, not just when the garage door is open.
So:
garage door open
new trigger enabled
car starts to leave the garage, turning the sensor OFF
once the car clears the sensors, the sensor turns back on and
the trigger fires, closes the garage door, and automatically un-enables the trigger.
There is a similar set of events for when I come home, and once the car is fully in the garage, the door automatically closes…
The new sensors are mounted close to the garage door opening, about 3’ off the ground. Once lesson I learned was to put the transmitter for the new sensor on the opposite side of the garage door as the transmitter for the garage door safety sensor…
The new sensors are mounted close to the garage door opening, about 3’ off the ground. Once lesson I learned was to put the transmitter for the new sensors on the opposite side of the garage door as the transmitter for the safety sensor
]