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Visitor II
February 3, 2020
Solved

Strange G value?

  • February 3, 2020
  • 3 replies
  • 1138 views

Hello, I just got a STEVAL-MKSBOX1V1 a few days ago, and had a problem on trying the accelerometer with the ST BLE Sensor APP. When I keep the sensor's Z axis up or down, the APP shows consistent +1g or -1g. However, when I put the sensor's X/Y up or down, it always shows alternately +/- 1g values. Why? Please refer to the following screen shots.0690X00000BxtxFQAR.jpg0690X00000Bxtx0QAB.jpg0690X00000BxtwbQAB.jpg

    This topic has been closed for replies.
    Best answer by Eleon BORLINI

    Hi @BLin.1​ , did you create an app with Expert view? And did you maybe activated more than one "accelerometer" sensor?

    You should select only one, differently the graph will show the data from both acceletometers going up and down between -+1g

    Regards

    3 replies

    Explorer
    February 3, 2020

    > ... with the ST BLE Sensor APP.

    I don't know that application, but their seems a disagreement between the sensor values and their interpretations in the app.

    The data are either normal noise (around 0.0g), or saturated values.

    BLin.1Author
    Visitor II
    February 7, 2020

    Thank you for the comment. Do you think it's a sw issue? I've also sent a e-mail to the contact address of this APP. There is no response so far...

    Explorer
    February 7, 2020

    I have MKI109 (sensor baseboard) with a MKI137 module (magnetometer). The ST-supplied "unico" application is showing proper proper values.

    I don't know the MKSBOX and supplied app, but Unico allows me to sample raw data, and save them to file.

    Perhaps the BLE Sensor APP can do the same, and you can review the raw values manually, if the make sense (what I expect).

    Reviewing the currently ongoing threads on this forum, it does not look like ST does very extensive testing with it's free apps. For what reasons soever.

    ST Employee
    February 7, 2020

    Hi @BLin.1​ , did you create an app with Expert view? And did you maybe activated more than one "accelerometer" sensor?

    You should select only one, differently the graph will show the data from both acceletometers going up and down between -+1g

    Regards

    BLin.1Author
    Visitor II
    February 10, 2020

    You are right. After disabling one of the 2 accelerometers, the problem is solved. Thank you.