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HHP.1
Associate
March 29, 2023
Question

1. what is the Inaccuracy of the data sampling rate? 2. What is the correlation of temperature with data accuracy?

  • March 29, 2023
  • 3 replies
  • 1010 views

0693W00000bh7PlQAI.pngI am using LIS2DTW12 MEMS,

1. I configured this sensor in continuous mode.

2. Set the FIFO threshold to 16 samples.

3. Selected ODR register value is 100.

4 Selected Low power 1 mode.

Expected:

Periodic interrupt from FIFO must happen every 160ms. But I am getting FIFO interrupt at ~158.4ms.

Could you please explain the cause of this time drift and how to fix it?

Note: our operating temperature range is -5 to 60 degrees C.

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    3 replies

    Federica Bossi
    Technical Moderator
    April 12, 2023

    Hi @HHP.1​ ,

    Welcome to ST Community!

    Looking at the data, a FIFO interrupt at 158.4 corresponds to measure an ODR of about 99Hz.

    We measure the ODR accuracy only on characterization data and so we can't guarantee min-max values in production but measuring 99Hz instead of 100Hz is acceptable according to our data.

    In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.
    HHP.1
    HHP.1Author
    Associate
    April 13, 2023

    Hello @Federica Bossi​ ,

    Thank you for your response.

    Is there any way to accumulate this frequency drift?

    Can you give detailed information on ODR accuracy in terms of %error?

    Federica Bossi
    Technical Moderator
    April 13, 2023

    Hi @HHP.1​ ,

    A drift over time is not expected.

    I can't give you detailed information because ODR Accuracy is not a tested parameter in production but according to characterization tests on a limited samples of data you can consider approximately up to 10%.

    If my reply answered your question, please click on Select as Best at the bottom of this post. This will help other users with the same issue to find the answer faster

    In order to give better visibility on the answered topics, please click on 'Accept as Solution' on the reply which solved your issue or answered your question.