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KDeli.2
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June 19, 2023
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iNEMO IMU LSM6DSOW: Pedometer Settings and low accuracy on the Step Counting

  • June 19, 2023
  • 1 reply
  • 1621 views

Hello, 

I am using ST’s LSM6DSOW sensor for the Step Counting of my project that’s a Wristband. 
The device is worn on the user's wrist. 

The settings that I am using for the Pedometer are as follows:

  1. Enabling the Pedometer Algorithm: PEDO_EN = 1 
  2. Enabling the Pedometer false-positive rejection block and advanced feature block: PEDO_ADV_EN = 1
  3. Initializing the Pedometer Step Counter: STEP_DET_INIT = 1
  4. Enabling the False-positive rejection feature: FP_REJECTION_EN = 1 
  5. Configuring the Pedometer Debounce, the accepted values are 0 to 255. 

During the testing of different Pedometer Debounce values it has been observed that:

  1. Compared to other devices (such as Apple, Garmin, etc.), the step count shows a deviation of approximately 20%. The tests were conducted with our Wristband worn on the same hand as the other devices.
  2. Our device does not count a small number of steps (e.g. 5-10) but only registers larger movements. Is this behavior related to the Debounce setting?
  • How does the Pedometer Debounce work? 
  • Do you have to suggest us some value for the Pedometer Debounce that will give the best possible accuracy? 
  • Do you have any suggestions or adjustments for the LSM6DSO sensor to increase the accuracy of step counting without using GPS or any additional sensor?

Thanks, 
Konstantinos 

 

    This topic has been closed for replies.
    Best answer by Federica Bossi

    Hi @KDeli.2 ,

    1. Our device does not count a small number of steps (e.g. 5-10) but only registers larger movements. Is this behavior related to the Debounce setting? Yes
    2. How does the Pedometer Debounce work? The step detector functionality generates an interrupt every time a step is recognized. In case of interspersed step sessions, 10 consecutive steps (debounce steps) have to be detected before the first interrupt generation in order to avoid false step detections (debounce functionality).
      The number of debounce steps can be modified through the DEB_STEP[7:0] bits of the
      PEDO_DEB_STEPS_CONF register in the embedded advanced features registers: basically, it corresponds to the minimum number of steps to be detected before the first step counter increment. 1 LSB of this field corresponds to 1 step, the default value is 10 steps. The debounce functionality restarts after around 1.2 s of device inactivity.
    3. Do you have to suggest us some value for the Pedometer Debounce that will give the best possible accuracy? around 10 steps is the suggested value
    4. Do you have any suggestions or adjustments for the LSM6DSO sensor to increase the accuracy of step counting without using GPS or any additional sensor? If you are using Unico GUI take a look to our video tutorial here and to our manual.

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

    1 reply

    F
    Federica BossiAnswer
    Technical Moderator
    June 23, 2023

    Hi @KDeli.2 ,

    1. Our device does not count a small number of steps (e.g. 5-10) but only registers larger movements. Is this behavior related to the Debounce setting? Yes
    2. How does the Pedometer Debounce work? The step detector functionality generates an interrupt every time a step is recognized. In case of interspersed step sessions, 10 consecutive steps (debounce steps) have to be detected before the first interrupt generation in order to avoid false step detections (debounce functionality).
      The number of debounce steps can be modified through the DEB_STEP[7:0] bits of the
      PEDO_DEB_STEPS_CONF register in the embedded advanced features registers: basically, it corresponds to the minimum number of steps to be detected before the first step counter increment. 1 LSB of this field corresponds to 1 step, the default value is 10 steps. The debounce functionality restarts after around 1.2 s of device inactivity.
    3. Do you have to suggest us some value for the Pedometer Debounce that will give the best possible accuracy? around 10 steps is the suggested value
    4. Do you have any suggestions or adjustments for the LSM6DSO sensor to increase the accuracy of step counting without using GPS or any additional sensor? If you are using Unico GUI take a look to our video tutorial here and to our manual.

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

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