Eliminate phantom acceleration with SmartThings Multisensor

#1

1) Give a description of the problem
The SmartThings multisensor acceleration sensor is notorious for phantom alerts. I have one resting on top of doorbell chime. I’d like to change the trigger from ‘acceleration changes’ to something like ‘any of the x,y, or z axis changes by a value of 100 or more’. If I choose x axis in Webcore there are comparisons for absolute values, but not for deltas so I can’t figure out how to set a minimum value.

How do you recommend to detect a change of 100 or more in any direction?

2) What is the expected behavior?
Detect acceleration but ignore the phantom events.

3) What is happening/not happening?
The sensor is notorious for detecting acceleration that isn’t there. Would like to add a threshold.

**4) Post a Green Snapshot of the piston!

doorbell piston anonymized
doorbell piston anonymized.png1178×696 39.4 KB

#2

I don’t know if this will help you or not, but I hated the phantom acceleration alerts too.

This is what I have done. With this piston (the second half of the piston), Essentially, two acceleration events have to happen within moments of each other to send a notification.

You_Doodle_2017-11-09T22_18_34Z
You_Doodle_2017-11-09T22_18_34Z.jpg1178×808 377 KB

#3

Thanks, I saw your post as well. Did this actually work for you? After reading your piston I looked at my phantom events which seemed to go inactive after 2 to 4 seconds, while my real events would go inactive after 4 to 5 seconds. With the overlap it didn’t seem like it would be reliable. I don’t really have a second instance of going active in my case.

#4

Reply, to keep me alerted on this thread.

I would love to find a way to use the multi on a skylight, to determine a trio of positions: closed, vent, open. The skylight apparently moves too slowly to even register, but I’m not convinced that’s the case…, so I’ll keep an eye on this thread, and see if any useful ideas pop up.

#5

I think I might give up on this one. Not only the phantom acceleration but I have horribly inconsistent results with it sometimes not turning on the second light (Dimmer 1 above), or not turning off Switch 9 ever. Scheduled events just aren’t reliable on this piston. I’ve tried fixing by setting cancellation policy to never, run the events asynchronously, etc.

#6

After a lot of trial and error the turn off events seem to work now that I’ve disabled command optimization on the piston. I can’t find many posts or documentation on what this does. Any doc pointers?

Have also changed my acceleration sensor triggers to activate when out of range on x or y axis. Will report back to this thread after sufficient time to determine if it eliminates the phantom activations.