High current consumption of BNO055

[mmurty]

Hello,

We are developing a wearable device which contains the BNO055 part.

I am presently experimenting with it and noticed that the suspend mode current consumption of the device doesn't match with the datasheet. The device datasheet mentions 40uA as the maximum current consumption whereas practically measuring it I get it around 80uA. I don't suspect the driver as I am using the driver provided by BOSCH on this github page: https://github.com/BoschSensortec/BNO055_driver and I follow all the steps demonstrated in the bno055_support.c file.

Please help me out with this.

[kgoveas]

Hi,

I will forward your concern to our dev team and get back to you when I have an update.

Regards,
kgoveas

[Alan]

here I measure the result is   39.4uA in suspend mode,  12.28mA in normal mode. 

• software : Development Desktop 2.0
• hardware:  App2.0 board + BNO055 shuttle board.   

          VDD/VDDIO 3.3v , PS0, PS1 Low,  nBOOT_LOAD_PIN High,  COM3 High

let's see if we can review your hardware schematic.

[mmurty]

Hello,

Thanks for your reply and sorry for my late reply.

I am attaching the schematic of my device. The pin states seems to be same as you mentioned. (Note: R17 and R18 are not installed on the board).

The sensor is being powered up from a 2.8V regulated source.

[mmurty]

Hi,

On our latest boards, I see the current consumption to be going around 160 uA in suspend mode. Just to make sure that I measure only BNO055 current I remove the ferrite L3 (as per the schematic in the previous post) and attach a current meter.

Also to make sure that there are no board level issues, I also measure current consumption on the Atmel BNO055 Xplained Pro board. On the Xplained Pro board the current consumption is around 196 uA. Current on Xplained pro board is measured by removing the 0 ohm resistor R113 and attaching a current meter in series.

I am also attaching pictures of current readings taken on both the boards for your reference.

Seeing this it seems to be a firmware issue to me hence I am posting my initialization sequence:

     1. Change operation mode to config.

     2. Remap Axis.

     3. Set output units and data format.

     4. Change operation mode to NDOF.

     5. Set power mode to suspend.

The clock source selected is internal RC oscillator.

Please comment on this.