BNO055 SYSTEM ERROR | RESET ISSUE

[rohitsoni]

HI Bosch Team,

We have deployed around 350 devices in the field and around 70 of the devices shows some BNO055 related issues. The behaviour is quiet strange. The device is powered on all time. The axis map resets automatically. We set it to AXIS_MAP_CONFIG 0x21,AXIS_MAP_SIGN 0x2 and after a while these config parameters set to AXIS_MAP_CONFIG 0x24,AXIS_MAP_SIGN 0x0. Again we hardreset it by pulling the reset pin low for atleast 1 second and we also set the RST_SYS bit to 1 in SYS_TRIGGER and hold for 1 second again and access the device.

Hard reset does the following job:

SetMode(BNO_RST,1);
 PinWrite(BNO_RST,0);
 delay(100);
SetMode(BNO_RST, INPUT_PULLUP);
 delay(500);
 setMode(OPERATION_MODE_CONFIG);
 delay(25);
 write8(BNO055_SYS_TRIGGER_ADDR, 0x20);
 delay(500);

After that too, We get System initialization error (case 2) in SYS_ERR register. I have seen on your forum about issue with i2c reset and that expects the external crystal after reset. However we have external crystal populated on the boards.

I have attached the circuit diagram for reference . Any immidiate help would be highly appreciated. 

Regards,

Rohit Soni

Wavenet Solutions

[rohitsoni]

Here is the circuit diagram for reference. Forgot to attach in the last case.

[o_o]

Hi Rohi,

Regarding the soft-reset and crystal issue:
There is a known issue due to the absent or damaged crystal connected to the microcontroller. This is documented by the microcontroller manufacturer at http://ww1.microchip.com/downloads/en/DeviceDoc/80000747B.pdf in chapter 1.5.7.

We will in time publish a new BNO055 firmware that fixes this issue, but for the time being we do not recommend using the reset. In case you want to reconfigure the BNO055 to known register values without a power cycle, I recommend that you write to each register the value of your configuration instead of performing a reset.

With regards to axis remapping, this is not an expected behavior. Could you please provide steps to reproduce the issue? Potentially also capture a datalog using a logic analyzer.

o_o