BMI088 accelerometer noise too high

I am migrating our design from the BMI090L to the BMI088. Both part datasheets state an accelerometer noise performance of 160 ug/sqrt(Hz) for X/Y, and 190 ug/sqrt(Hz) for Z. I am observing significantly higher accelerometer noise for the BMI088 as shown in the plots below.

The parts are mounted on identical host boards and use the same configuration: GYRO_RANGE_2000_DPS, ACCEL_RANGE_24G, and ACCEL_DATA_SYNC_MODE_400HZ. I am using the latest drivers for both parts.

If i remove the line bmi08a_load_config_file(&dev) from the BMI088 set up code then the accelerometer noise performance is improved significantly as shown in the plot below.

I suspect there is an issue with the BMI088 driver.

Best reply by FAE_CA1

Hi,

We are able to reproduce the high BMI088 accel noise issue by following your code. And we found the root cause in your code.

Basically you should place "bmi08a_load_config_file(&bmi088);" right after the "bmi08a_soft_reset(&bmi088);" and then configure the accel. Now you place "bmi08a_load_config_file(&bmi088);" at the end so that the accel configurations above will be lost or get reset. Therefore, the accel noise level is high. We have verified that once the load config file line of code is below the soft-reset line of code and above those accel configurations, the accel noise level is low.

Thanks.

View original

8 replies

Resolved