Help understanding SODAQv3 Accelerometer lectures

ONE
1

Hello!

I’ve been testing the SODAQv3. So far I have the following doubts regarding the accelerometer. I’ve been using these library: https://github.com/SodaqMoja/Sodaq_LSM303AGR

  1. When configuring the accelerometer with FS 16g, and putting the SODAQ board pointing to the center of the Earth, the Z axis is between 0.6g and 0.7g. What are these values? Shouldn’t it be 1g? In all the other cases we tested (2g, 4g, 8g) it was 1g.

  2. When configuring the accelerometer with FS 16g and Low Power Mode, the sensitivity should be around 187.58 mg/LSB (±7%) according to the datasheet. Does this mean that between each lecture of the accelerometer, we should expect a difference equal or bigger than 187.58 mg/LSB (±7%)? I mean, is it possible to have a difference of, for example, 50mg/LSB between 2 lectures with that configuration?

Thanks

2

@marianofino,

We have replicated the issue.
We are working on a fix, there should be a fix published before the end of next week.

Best regards,
Jan

3

Thanks for the reply @Jan .

The issue you are working on is related with my first or second question? Or both?

4

@marianofino,

  1. We updated the library.
    We are still waiting on for a reply from ST to implement some final changes.
    Let us know your results with this version.

  2. The higher the g the less accurate the sensor will be.
    Each step is for 16g 187.58 mg/LSB with a correction from -7 to +7 %

Best regards,
Jan

5

Hello @Jan

I can confirm that, from our tests, both issues seem to be solved. However, now we are facing another issue regarding reading weird accelerometer values. I’ll update the message here once I create a new topic.