I'm looking for a way to positively identify the presence of a car in a garage.
The purpose is: (1) if the car is present inside the garage, and (2) the humidity is high OR rain has been detected [have to figure that last one out], then (3) turn on a fan to dry the car and floor until (4) the humidity goes below a set value or a timeout expires.
I don't want to build my own circuit board, but I am willing to adapt a component (e.g., a different mount).
I'm looking at a Tuya "SmartZigbee Ultrasonic Liquid Level Water Tank Monitor Sensor", pictured below. I think this should work with a ceiling mount (the monitoring distance is sufficient to detect the floor versus a car), although I think I'd have to rig a different mount since I believe the flange-side is where the transducer is located (hence the unit is upside down for a ceiling mount).
Does anyone have experience with this type of unit and integrated it with Hubitat (driver available)?
I have worked with ultrasonic level transmitters inu work. The flange is normally on top of a vessel flange. The electronics are above the flange. The sensor is inside the flange facing down.
This type of device measures the distance from the flange to the reflective surface. In your application, the top of the vehicle or the floor.
Suggest that you look at the mm-wave presence sensors. They use the same frequency as the radar level transmitters
I’m using an ultrasonic sensor to detect if my car is in the garage or not. Works great.
When I was looking for a solution to detect when my car is in the garage, I didn’t find a subtitle sensor. I want with ESP32 in Home Assistant.
It wasn’t that hard to get it up and running but if you find a good working sensor that you can integrate directly into HE, let me know.
I will then replace my ESP32 solution. I want as much as possible directly integrated in HE.
I bit the bullet and ordered 2 of the Tuya "SmartZigbee Ultrasonic Liquid Level Water Tank Monitor Sensors", pictured above, before the tariffs hit the previously exempt low value mailed exports from China.
I'll report back if I can make them work with Hubitat and for my application.
I'm not sure presence sensors fill the bill: would a stationary car generate a different signal than a stationary floor? In other words, do the presence sensors report a detected distanceperiodically?
Not sure how a tilt sensor on a string detects the presence or absence of a car, unless the car disrupts the string/sensor from vertical when parked in the garage (i.e., I'm picturing your implementation as an electronic version of a tennis ball on a string, typically used for indicating proper parking position).
As a follow up, I mounted two of these ultrasonic sensors on my double garage ceiling using heavy duty hook and loop strips. They are working quite well for my purposes.
I originally tried to precisely measure the distance between the sensors and the garage floor, and got pretty close. But after I activated the sensors, I realized that they themselves could determine their own distance by whether the nominal value I used resulted in a negative number. For example, I put in 2.9m and both units were registering -0.1m. Accordingly, I adjusted the installation height parameter to 2.91m and they generally register 0m when a car is absent. Note that they actually have a resolution of about half a centimeter.
Last note, in order to increase the WAF, I covered the orange shell of each sensor with white electrical tape. If I get ambitious, I will carefully spray paint them white.
I transferred my 2 MoreyAlec (Tuya TS0601 based, _TZE284_kyyu8rbj is the source) ultrasonic sensors to a new hub (C8-Pro) located in my garage. Since then, both units have been reporting a Level of 188 -- which is an impossible value.
The logs just corroborate the Current States value of Level:
2025-07-17 04:10:30.333 PMinfo
Distance Sensor - Ultrasonic - Garage North level is 188 %
The installation Height is correct (ceiling to floor of my garage), and the Liquid Depth in this clip is correct (distance from ceiling to my car). Driver is "Tuya Zigbee Tank Level Monitor".
Any thoughts on how to resolve this anomaly?
Platform Version: 2.4.2.131
Hardware Version: C-8 Pro
Have you tried pairing the liquid level sensor again to your C-8 hub (without removing it)?
Is the Ping() command returning numeric round-trip-time values? Make sure the driver is the latest version, it was updated in April this year.
The Level percentage value is calculated and reported from the sensor itself, so the only reason for reporting a value over 100 that I can think of is if some of the configuration parameters were not accepted correctly.
After I posted, I re-paired my south unit 3 times in a row, and it now seems to be behaving -- RTT of 156, Level = 53% (which is correct for the distance from the ceiling to the south parked car).
I didn't re-pair the north unit, which was reporting RTT, but I did change the driver to Device and cleared everything, then changed back to the Tuya Zigbee Level Monitor. When I checked a couple of hours later, RTT was 256 and Level as 56% (which is correct for the distance from the ceiling to the north parked car).
The driver is ver. 3.4.0 from 2025-04-25.
So it seems (for now) to be resolved, and was likely an internal config problem as you noted.
