Spikes in the LIS2DH12 accelerometer raw data

[soundarya1]

Spikes are present in the data coming from the LIS2DH12 accelerometer when placed in a casing, but when it is in the open there are no spikes. Attached is an image of the 3 axis data plotted from the accelerometer when placed on the table with casing and rotated. I have also added another plot of the same device on air (no movements). Please advice how to mitigate this issue. Thanks.

 

 

 

[Federica Bossi]

Hi @soundarya1 ,

Welcome to ST Community!

Can you give us more details about your casing? Is it possible that it is in contact directly with the top of the LIS2DW12?

[soundarya1]

Hello @Federica Bossi,

The casing/enclosure has no direct contact with LIS2DW12. It only encompases the entire device. There is nothing else placed above LIS2DW12. 

 

[soundarya1]

Also, the casing is ABS casing, there is 5mm+ of space present between the casing and LIS2DW12. 

[Federica Bossi]

Hi @soundarya1 ,

When you put the LIS2DH12 in the casing and it doesn't rotate, what do you see? can you share a graph?

In addition, can you write me your settings? ODR, FS, BDU...

[unsigned_char_array]

Could be vibration. Have you rotated at different speeds? What is the spectrum of the spikes? Perhaps the enclosure has a certain resonance frequency that causes issues.

Also the data looks like it's a modulo of the real data. It overflows/wraps around. You can see that around t=1250 the x and y values slowly cross the boundary and then wrap around. If you remove the overflows from the data does it still have spikes? Or is it bouncing around 0.0/0.8?

Can you attach a csv file of the raw data? (integer not floating point)