I am confused about the sample rate values that I can use for my IMU and the configuration mode of it as well. In the documentation it states that the data output rate is 100Hz, so I understand that as the maximum sample frequency I can use, but it also states that the default bandwidth frequency (which cannot be changed in fusion mode) of the accelerometer is 62.5Hz, which doesn't makes sense because the Nyquist sampling criterion must be respected: Bandwidth = 1/2 Fs.

For my project I am obtaining data with the callback function each 8ms (2 * 62.5Hz), The data seem ok, but I still want to understand how the sampling rate and the bandwidth work in this sensor to be sure if I change my sampling rate, I won't end up out of the limits of the sensor and with erroneous data.

 

Take a look at the datasheet of the BNO055: https://raw.githubusercontent.com/Tinkerforge/imu-v2-brick/master/datasheets/BNO055.pdf

Pages 26/27 for the accelerometer default configuration and page 31 for the sensor fusion data rate.

I don't know how this works exactly with the 100Hz vs 62.5Hz, unfortunately the sensor fusion algorithm that Bosch uses internally is proprietary.