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    BNO055 Sensor behavior with horizontal rotation

    BNO055 Sensor behavior with horizontal rotation

    Established Member

    Hi Everyone,

    1. As we are a product based company, We purchased BNO055 Sensor Dev kit for our development, and we are evaluating it for our requirement.
    We found an observation that, when the sensor is an horizontal rotation(say 90 degree in heading ) and if usb dev kit is unplugged and plugged, and opening Bosch Development Desktop UI again means, we are getting 0 degree in heading information when we are in relative and absolute modes (IMU plus and NDOF )
    2. As per datasheet, it should have some difference in it's heading information, but we didnt see any difference in both the modes. and seeing only 0 degree after power on, even if it is already in 90 degree position.

    So please provide your support to overcome this issue.

    Thanks in Advance,
    Uma Maheswari.G

    19 REPLIES 19

    Occasional Contributor

    Hi Sir:

        Regarding calibration, please see my following comments:

        1. Before installed to your product, ACC calibration can be finished first, if no bending stress, it will not be needed to calibrate again.

        2. It is easy for GYRO to calibrate, only keep sensor still and wait a few seconds, calibration will finish.

        3. But MAG calibration is hard to finish, three-dimensional space is necessary. Use calibration software with standard 'figure-of-eight movements to do the hard iron calibration and compensate for distortions affecting magnetometer readings, or with the help of gyro, at least your device slope 30 degree to finish it , which way is smart calibration software with 'natural-use movements'.

        So if when the magnetic field is changed, Mag calibration have to do in order to ensure to get the correct data.

        If need the absolutely orientation, NDOF mode should be chosen, if don't care the start orientation,only need relative change, IMU mode can be chosen.



    Established Member

    Thank you sir for the reply. it is very useful.

    we are in the process of evaluating BNO055 to use in a way which is consuming less power and provides stable output irrespective of the magnetic field.

    here is our queries.,

    1. Is it possible to use gyro in low power mode? if yes, which registers to be used for configuration( no datas available in the datasheet)
    (in the datasheet you mentioned with out accelero, low power mode is not possible. in your UI Ver there is an option to select gyro in low power mode)

    2. In the datasheet you are mentioning write possible only in config mode -> but exception is interrupt registers and operation modes.
    so i am trying to switchfrom IMU mode to Gyro only mode with out soft reset (without entering into config mode) .But i am getting error as write failed with error code(0x03) is it possible to switch between operation modes when the sensor is streaming i,e out of config mode.
    if yes, how i need to switch between operation modes with out soft reset. 

    3. In Gyro only mode with out writing any gyro configuration with your default configuration, the power was somehow low from IMU mode.
    But if we configure any values in the gyro config registers or even with the default values which you provided only write operation triggered itself consumes power more than 10mA which is nearing IMU mode.
    Then what this operation modes in gyro configuration registers like advanced power save option? where it will be useful to reduce power consumption.

    Please clarify our queries.
     it will be more useful if you reply with details

    and also it will be useful for us to get single person contact for more detailed technical queries.

    Thanks & Regards,
    Uma Maheswari.G

    Occasional Contributor

    Hi Sir:

        Please see my comments:

       1. Gyro in low power mode is unavailble. Single Gyro, bmg160 has its own low power mode, but in BNO05,  it is possible to use single gyro in low power mode.

            Recommend you to know BNO055 low power mode, with any motion interrput to switch power mode.

       2. If you switch operation mode, it is necesary to enter into config mode to switch them.


       3. Like 1 what I said, if you want to save power consumption, you can choose any motion feature.



    I believe the magnetometer sensor need to be recalibrated every power off. Reusing calibration data only works for ACC and GYRO sensors.

    I also experience the same issue.

    Established Member

    Hi Jet, 

    Thank you for your reply. it was really helpful for our further analysis.

    i am doing soft reset to come out of suspend mode and collect the position data in IMU mode.

    when doing soft reset, most of the time sensor got stuck. and not coming out of the reset function.

    Here is the array in UART we are sending for soft reset operation - {0xAA,0x00,0x3F,0x01,0x20}
    we will wait for transmit flag set for the successful transmission of  each byte.

    but for this reset operation we are not receiving transmit flag set from the microcontroller after sending 0x20. 

    this is happening very frequently. and no idea what could be the reason.

    Please help us to resolve the issue.

    Thanks & Regards,
    Uma Maheswari.G