BNO055 MAG_DATA is shifted no offset value when not move in NDOF mode.

[T_Kozaki]

Hi everyone,

Please tell me a workaround or what to do!

BNO055 is used in OPERATION_MODE_NDOF.
I know NDOF mode has offset in MAG_DATA by other sensor.

But...
When BNO055 does NOT move for a 10 - 20 seconds,
MAG_DATA is shifted no offset value(unexpected value).
And give shock to BNO055, return offset value(expected value).

I want to anytime keep MAG_DATA to offset in NDOF mode.

----- exsample ----
x: -9.0
y: 57.0
z: 9.0

don't move....

x: -17.0
y: 95.0
z: 15.0

give shock BNO055

x: -9.0
y: 57.0
z: 9.0

[Vincent]

I'm not able to reproduce this issue when using NDoF mode. 

If you don't move the device for long time, the magnetic data will keep drift or just change to one value like without offset? 

At the same time,  do you see heading drift also? 

Please double check if you have big magnetic distortion around the sensor during sensor run time. 

[T_Kozaki]

Hi Vincent,

Thank you for your answer!

I accept you aren't able to reproduce.
I want to find something different between you and me.

I answer your questions
Can you come up with something an different??

>If you don't move the device for long time, the magnetic data will keep drift or just change to one value like without offset?
Yes.(Please see following reprocedure data)

>At the same time, do you see heading drift also?
I checked an EUR_Heading data. answer is No.(it means no drift EUR_Heading data)

>Please double check if you have big magnetic distortion around the sensor during sensor run time.
I still confirm that this issue happen in stable magnetic field.

--- I reproduce again ---
IMU is not move in following procedure.

1.boot in AMG mode(not offset by fusion mode)
x: -49.0
y: 45.0
z: 41.0

2.write program for NDoF mode and reboot.(still not offset by fusion mode)
x: -49.0
y: 46.0
z: 42.0

3.give shock imu(offset by fusion mode)
x: -29.0
y: 28.0
z: 25.0

4.about 15sec later(not offset by fusion mode)
x: -48.0
y: 45.0
z: 41.0

5.keep this value continued for more than 5 minutes after that.

[Vincent]

I saw a reboot in step 2. 

Normally,  sensor is power cycle to CONFIG mode,  then change to proper working mode manually by user. 

If you select NDoF mode, then reboot,  you need to configure it as NDoF again.  Hope you are not miss the steps.

PLease also print out the magnetic calibration status.  If the calibration status changes from 3 to 2 or even 0 when the magnetic data changes,  then it is caused by magnetic distortion.

[T_Kozaki · Accepted solution]

Sorry for my late.

And I understand this issue's reason.

This phenomenon was the behavior before calibration.

It does not occur after calibration.

I am solved with this

Thank you for your kindly support!