RMS of acceleration signal

bryhoyt

I would like to configure my MetaWear sensor to only report an infrequent "average" (i.e. RMS value) of the high-frequency signal over a period of time.

For example, I would like it to record acceleration at a high frequency, say 400Hz, and calculate the RMS value over a period of 1 second, without reporting the intermediate values via bluetooth. Only the 1-per-second RMS value should be reported. I assume this would dramatically improve battery life, since the biggest drain on the battery is the radio comms.

Is this sort of thing possible with the data processing API?

Eric

off hand, I don't see why it wouldn't be possible.

bryhoyt

Ok. I can't figure out any way to do this on the MetaWear board using the data processing API.

How would I go about doing this using the Android data processing API? What API is used in order to accumulate data before processing and sending?

Eric

The one named "accumulate" would be a good start:
https://mbientlab.com/androiddocs/latest/data_route.html#accumulate

You can also apply a low-pass filter over the data as well:
https://mbientlab.com/androiddocs/latest/data_route.html#low-pass