Angle vs. magnet on samsung multipurpose sensor


(Luigi Semenzato) #1

I am playing with the multipurpose sensor to detect forgetting the garage door open.

I started by setting the device to “garage door” which detects changes in the sensor orientation (horizontal vs. vertical). This proved to be unreliable: a large number of orientation changes were not reported, or the reports were lost.

Then I changed it to use the magnet sensor, and the reliability went up to 100%, so far.

Why the discrepancy? I have difficulties coming up with a sensible explanation. I have also noticed that the device reports temperature changes as well. This morning it’s been raining heavily and the line of sight between the hub and the garage goes through some rain. The log shows that the temperature change reports have stopped (and in fact the ST app thinks that the device is “unavailable”). Yet when I drove away, the OPEN and CLOSE events were reported correctly.

To add to the confusion, I experimented with moving a Sylvania Smart plug (Zigbee) close to the sensor, to improve its range. I actually don’t know if this was useful or not, because I don’t know if the network will reconfigure on its own or how long that takes. It’s clear that the Multipurpose sensor can reach the hub on its own, but not reliably—thus figuring out any improvement is a lengthy proposition.

I just thought of something. This is an old swing-up door. The magnet sensor triggers at the beginning of the opening, the angle sensor triggers in the middle. The door motor works lightly when the door is almost closed, and a lot harder halfway during the opening. More current = higher EMF interference… agh. But this still doesn’t explain why I stopped getting temperature events.


(might be my fake name?) #2

I don’t know when you were testing it as a garage tilt sensor, but last week ST acknowledged that they were having "orientation " issues with ST multipurpose sensors. Those issues have since cleared up.


(Luigi Semenzato) #3

Just my luck eh? I was testing mostly last week-end (8 days ago). I did some testing yesterday too, but not that specific test (checking for angle events while mounted on the garage door).

It’s still strange that the temperature events have stopped and the device is listed as “unavailable”, but it managed to report this morning’s open and close events. Is it possible that the Samsung engineers decided that those events are more important and it’s worth spending extra energy on them?


(might be my fake name?) #4

I would turn off “device health” too. There are known false positives with that. Search the community here and you’ll see that "device health” is inaccurate.


(Luigi Semenzato) #5

Thanks. I haven’t been checking the “device health”, unless it is somehow related to the “unavailable” status. Maybe the hub expects pings every so often?