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Getting Started with the Multiple Device Demo

DarilbiiDarilbii
in Android
I am new to the mbient system and am currently trying to implement a project utilizing multiple (5-7) metawear systems at the same time. I think the Demo described in (http://projects.mbientlab.com/using-multiple-connected-metawears-with-android-api-v1-3/ ) would be very useful to implement this, however the demo doesn't seem to work using Android Studio. Does any have any solutions to this? It appears because the demo was not created using Gradle.

Comments

  • EricEric
    That project uses a very early version of the API, which is long outdated.  

    The simplest solution of course would be to wait for the project to be updated however, I'd suggest building a simple app yourself.  There isn't any special trick to using multiple MetaWear boards with the same app; you simply call getMetaWearBoard multiple times with the MAC address of the boards you want.
  • sonalideosonalideo
    We have tried to connected to multiple devices at once with getMetaWearBoard with different mac adresses. It works fine in the beginning with up to 3 devices but after a while they stop streaming/downloading logs. With 5 devices it goes even faster until some of them stop sending data if it at all is possible to connect to all of them.

    Any other specific things that needs to be done? We have been running on different android tablets with android 4.4.2 and 5.1.1. How many boards in parallel have you been able to run on Android with streaming?
  • EricEric
    How fast are you streaming data from the boards?  You need to scale down the data frequency accordingly if you are collecting data from multiple boards.
  • sonalideosonalideo
    Have done some test now with accelerometer streaming at 10 Hz. Apparently it's the hardware/android version that sets the limits here. Some data from simple tests that can be useful for others:

    * Lenovo 7600F. Android 4.4.2: 2 devices usually. Can sometimes connect to a 3rd. More devices results in connect returning in failed connect immediately.
    * Lenovo yoga tablet 2, Android 4.4.2: 4 devices usually. Sometimes can connnect to a 5th. More devices failure immediately
    * DragonBoard 410c, Android 5.1.1: 6 devices connected, however sometimes devices stop streaming when reconnecting to them..
    * Samsung galaxy s6 edge Android 5.1.1: 6 devices working good (was the maximum available for me to test on)
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