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Calibration / Taring Sensors to 0 (Quaternions)

Alecl17Alecl17
in Android
Is it possible to force the sensors to register at 0 initially? Using NDOF even after calibrating by using figure 8 like motions the sensors still don't have the same values in all orientations. For example, one sensor will be the negative of the other. (Sensor 1 = 0.98 and sensor 2 = -0.98). I've tried IMU_PLUS as well but there seems to always be some difference between both values.

I'm trying to compute the angle between two sensors as they move... but in order to do that, I would need to set their default position to 0.

Comments

  • Alecl17Alecl17
    Okay, so it seems that if I connect the sensors to the meta-base app, and then re-run my app again using IMU-PLUS, the sensors work perfectly. What am I missing in my application that causes the difference in values after a while?? Do I need to use a teardown function or something to remove the boards prior to closing?
  • Alecl17Alecl17
    The final thing to add here... IMU-PLUS is supposed to take the relative orientation from where the device is when it is initially connected correct?

    In my application, It doesn't always do this. If I got into the metabase app > Diagnostic > Reset both sensors, and then try my app again, everything is working as intended.

    If I run my application and close it, next time I reconnect to the sensors it seems to remember their position from the first time I've connected them in my app.

    What exactly is happening in the Metabase app when i reset the sensors... If i can make sure that this process occurs before beggining to collect my data, then it would work perfectly.
  • EricEric
    edited February 2018
    https://mbientlab.com/docs/metawear/android/3/com/mbientlab/metawear/module/Debug.html#resetAsync--
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