Cyton data stream, 'Packet dropped!' from OpenViBE

JuanPGJuanPG Argentina
edited February 2019 in Cyton
Hi,
I'm working with OpenBCI a few months ago in Windows 7. I never modified any code on the board and i have always the same problem: testing the Cyton with a know signal (sinusoid), the data has lost packets.
First, acquiring through OpenBCI GUI and analyzing data, these losses appears:

image

Then, testing with OpenVIBE & OpenBCI, the problem is highlighted in the acquisition: 'Packet dropped!':

image

I have already changed the latency time settings and the transfer sizes according to the tutorial of OpenBCI, and the problem persist. I have also tested different ports and different hardware configurations for sampling, but isn´t solve.
What can this fault be caused or what can I prove or modify for solve this problem?
Thanks for the space!

Comments

  • wjcroftwjcroft Mount Shasta, CA
    Juan, hi.

    One thing to try would be to rule out the possibility that there is radio frequency noise / interference in the area in which you are running your experiments.

    Try moving to another room or building where the conditions may be better. It's also advised to keep cell phones, power supplies, power conduits away from the immediate vicinity of the Cyton / dongle. 

    You can also change the radio channel that Cyton is using, which might move away from a noise source,


    Regards,

    William

  • JuanPGJuanPG Argentina
    Hi, William.

    Thanks for your quickly response. I will try with this in the next days, and comment the results.

    Regards,

    Juan.
  • wjcroftwjcroft Mount Shasta, CA
    Another thing to check in the CSV output from the GUI: do you see the sample index / packet counter advancing sequentially one step at a time? Or are there gaps?
  • JuanPGJuanPG Argentina
    In the CSV exist missing indexes. I see, for example:

    0, 1, 2, 4, 5, 7, 8, 11,...

    Any idea?

    Thanks!
  • JuanPGJuanPG Argentina
    I tested with different channels and the result is the same: the indexes jump as i said before.
    Aproximately loses at a rate of 50 samples per second (sampling at 250Hz) in any of the channels.

  • wjcroftwjcroft Mount Shasta, CA
    Thanks for checking the CSV, that verifies the packets are being lost. Did you try my previous suggestions? Does your laptop CPU resources available to service the dongle? Another thing you can try is moving the dongle closer to the mainboard.
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