Sensitivity on ST MultiSensor


(Ed) #1

Guys

Was wondering if you can help as I don’t have a spare ST multi sensor to test.

I plan to install a multi sensor on a flap configured as a garage mode (ie without a magnet). The flap position is normally vertical. When the flap is opened, it’s at most 30-45 degrees from vertical. Is it enough to register a change (acceleration) within the device?

Does it need to be purely horizontal to register any change? Thanks.


(Eric) #2
  • I expect 30degrees is enough but I don’t know the minimum.

  • acceleration property is not the same as angle/orientation property which seems to drive opened/closed status. Acceleration DOES indicate if the sensor is “active”.

  • so I expect no, it does not need to be “purely” horizontal (to indicate opened). “Nominally Vertical” orientation seems to be the default position to indicate closed.


(ActionTiles.com co-founder Terry @ActionTiles; GitHub: @cosmicpuppy) #3

The accelerometer measures 3-vectors of G-Force, including actual gravity towards the center of the Earth (aka, “down”). Even miniscule changes in the orientation of the sensor (eg, 1°… yes, 1 degree) is more than sufficient for it to register a change in the orientation.

It is up to the software (the Device Type Handler and/or SmartApp) to define what levels of vector delta represent an open vs closed door.

This is the tremendous advantage of an accelerometer based sensor instead of a less expensive (but quite functional) enclosed ball bearing tilt-sensor.

Dig up the applicable source code to find out what parameters have been set to define delta orientation.


(Ed) #4

I’ll be using Rule Machine. Will check code. Many thanks @ero4444 and @tgauchat.