LTE-M Beacon Accelerometer - Z Axis 'too sensitive'?

LTE Beacons
1

Hello,

I am testing several LTE-M Beacons , particularly their accelerometer feature, and seeing while moving the beacons by hand on my desktop that the Z axis value seems to be consistently much higher than expected compared to the actual movement compared to the values reported for the X and Y axes.

The behavior is identical across all the 10+ LTE-M Beacon devices I have - for example, moving the device (oriented on the desk such that the cloud icon is facing directly away from me) suddenly forward results in a reasonable X axis acceleration value, however I also receive a 1.0 or higher Z axis reading without the LTE-M beacon moving appreciably in the Z axis direction (up).

I am wondering if other users are seeing similar behavior with the Z axis values reported much higher than expected given the actual movement occurring, and also if the Estimote engineers could investigate whether there may be an issue with the LTE-M Beacon firmware causing the reported Z axis accelerometer values to be higher than they should be.

Thanks!

2

What does it mean it is much higher? 1.1g, 2g, 10g? Can you provide some numbers? Have you changed default accelerometer settings?
If the surface you are moving your beacon on is not perfectly level (orthogonal to gravity vector and parallel to accelerometer die) then a sudden movement in X/Y axes will translate to acceleration in Z axis (caused by inclination). Also vibration caused by movement on non-smooth surface may induce some acceleration on Z axis.

3

Hello! Thanks for responding - Upon further thought, I realize that I was not considering that at all times a G force of 1.0 is exerted on the device on the Z axis if the device is oriented upright on a flat surface - My original thinking was that the device would report G force factoring out this 1 G.

So I can simply subtract the 1.0 G force (unless the beacon is in space or on the moon :slight_smile: ) to get the Z acceleration change value I was looking for.

So I do not have an issue - and the accelerometer values I am getting are fine.

Thanks!