LIS3DHTR ''noisy'' output

Rob1 · ‎2016-11-01

Posted on November 01, 2016 at 10:14

I'm trying to get an LIS3DH accelerometer working and I have a question about the output data.

It seems to be very ''noisy''. I have the board with the accelerometer on a flat table.

I've set the data rate to 100hz and 2g fullscale , high res mode on.

The data seems to jump all over the place. If I tilt the board fully one direction I get about 16000 counts

and fully the other direction I get about -16000 counts, which seems to be about right.Still very noisy

around the main reading.

when it is flat on the table I get anywhere from +128 to - 128 counts. Counts change in increments of 16.

Is this normal behavior?

Cheers

Neddie

Miroslav BATEK · ‎2016-11-02

Posted on November 02, 2016 at 16:41

The output data are 12bit, left justified.

You have to divide the raw data by 16 (shift right by 4). For 2g range the sensitivity is 1mg/LSB so you will get directly the value in mg.

The noise of +-128 counts means +-8mg which is in line with the datasheet.

Best regards.

Miroslav