Sampling and Fusion rates

[j_perezdelarray]

I would like to confirm if the following configuration of sampling and running rates are ok.  According to the sensor fusion manual (p.45) it should, but would like to confirm.

We'rebasically looking to increase the 6DOF fusion rate to improve output values. Let's assume there's no power budget.

Would the following configuration work?

- FXLS8471Q + FXAS21002 at 400Hz ODR, 

- Software sampling rate of 1600Hz: (oversampling and averaging sensor outputs to minimize noise effects)

- Fusion rate of 400Hz.

If we wanted to increase the filter rate above the sensor sampling rate, would it still work?

Thank you,

[shubhadippaul-b]

Hi,

The configuration that you stated should work, however based on my discussion with michaelestanley, you may want to consider the following points:

• Sampling at Rates higher than the Sensor's ODR for digital sensors would not yield any benefits. For your configuration, you will simply get 4 identical samples before every new sample.
• Polling a digital Sensor for Data at significantly higher rates than it MAX ODR may introduce noise.
• Running your Filter at rates higher than the Sensors ODR would mean running it on the same data set. This again may not yield benefits unless there is sigma-delta (some parameter which changes at every cycle).
• Reading Samples at 400Hz form 2 Sensors configured at 400Hz ODR and Running Fusion at 400Hz should be fair implementation. However, you may need to optimization your UART usage to free up enough resources to cater for the increased Sensor Data and Algorithm loads.