Inconsistent frequency when streaming at 50hz.

kkflf

Hi

I am using MetaMotion R with firmware version 1.3.3.

I am using the following two gradle dependencies for mbient:

compile 'com.mbientlab:metawear:2.5.9'
compile 'com.mbientlab.bletoolbox:scanner:0.2.0'

I am streaming both accelerometer and gyroscope at 50hz.

I have performed multiple tests by streaming 30-45 min data.

I have discovered that I am only streaming about 40hz instead of the 50hz.

You can see my mbient specific code here:

http://pastebin.com/20p80bF1

I am trying to revise how I stream the data, so I looked at the documentation and tutorial once again.

It looks like the documentation and tutorial are using two different ways of streaming. What is the difference?

Documentation:
https://mbientlab.com/androiddocs/latest/data_route.html#stream

Tutorial:
https://mbientlab.com/docs/apis/java/template-app/

Kind regards
Kristian

Eric

A new Android APi was relased 2 weeks ago, tutorials are in the process of being updated   

At the very least, you need decrease the max connection interval as outlined in this section:

https://mbientlab.com/androiddocs/3/advanced_features.html#high-frequency-streaming

It is for API v3 but the values / process is the same as API v2.

kkflf

I have tried to update my code to comply with the new API version 3.

I know that the tutorials are not out yet, but I wanted to try it out and see if it solved my problem.

You can see the code regarding mbient here:
http://pastebin.com/QhdHwtb7

I am trying to create streams for accelerometer and gyroscope at 50hz. But the Log.i() is not posting anything, so it seems like they are not actually streaming.

I have tried to call readDeviceInformation() and it print the following, so I know the sensor is connected properly.
{manufacturer: MbientLab Inc, serialNumber: 004F20, firmwareRevision: 1.3.3, hardwareRevision: 0.1, modelNumber: 5}

Eric

You need to start the data producers and creating acc/gyro routes should be coded by chaining tasks.

https://github.com/BoltsFramework/Bolts-Android#chaining-tasks-together

https://mbientlab.com/androiddocs/3/accelerometer.html#acceleration-data

kkflf

Thanks

I can now stream with both sensors again.

Is there a onDisconnect event trigger? Such that you can enable led or logging if the sensor disconnects?

Eric

https://mbientlab.com/androiddocs/3/settings.html#handling-disconnects