Bosch BNO055

[Hadrien_Menu]

Hello,

We are currently facing a BNO055 issue.

We want to use BNO055 to monitor absolute angular position of a device (could be in any position).

In order to save batterylife, we are doing the following (after proper calibration of the chip) :

Calibration

Loop :

            set BNO055_OPERATION_MODE_CONFIG

            set BNO055_POWER_MODE_LOWPOWER

            wait 10 seconds (here power consumption about 180uA) 

            set BNO055_OPERATION_MODE_CONFIG

            set BNO055_POWER_MODE_NORMAL

            set BNO055_PAGE_ID_ADDR

            set BNO055_OPERATION_MODE_NDOF

            monitor BNO055_CALIB_STAT_ADDR

                        untill the 4 values sys, gyr, acc, mag = 3

            read quaternion

            extract yaw

            display yaw

If we are doing this loop without seeing BNO into suspend mode, result is fine, and angle reported is OK.

If we put the BNO in suspend mode, as described in the loop, despite the sys is set to 3 (means mag as find the north), the angular value reported is always « reset » to the almost same value.

It looks like setting the BNO in suspend mode is affecting calibration.

Could you please advice?

Thanks for your support.

Br,

[FAE_CA1 · Accepted solution]

Hi,

Thanks for your inquiry.

BNO055 has sensor fusion running inside when accel, gyro and mag sensors are in normal mode. When BNO055 is in suspend mode, all sensors will be in suspend and the sensor fusion will stop running too. The sensor fusion results such as Euler angles, quaternions, etc. will remain unchanged.

Thanks.