how can I avoid the time series with glitches irregularly spaced ?

Hi, the link is my a EEG data by 1000Hz sample rate, but it has a time series with glitches irregularly spaced, I want to avoid it because it influence the data processing, who I help me to avoid the glitches, or who can tell me why it will product the time series with glithces irregularly spaced??? Thank you!


Comments

  • wjcroftwjcroft Mount Shasta, CA
    Your photo link does not work. Try posting on Google Drive.

    re: glitches with Wifi Shield, are you using UDPx3, that is the most reliable and fastest.

  • wjcroftwjcroft Mount Shasta, CA
    Glitches on your time series seem to be happening a bit more than every .1 second. What protocol are you using, tcp, udp, or udpx3?

    Are you sure your firmware is up to date on all microprocessors (shield, mainboard, etc.)
  • Yes, I am sure the firmware is up to date because I just bought the new shied and mainboard on May, I use the TCP protocol, can you give me idea which protocol is the best? I need avoid the glitch on time series by 1 second for 10 times like.

  • wjcroftwjcroft Mount Shasta, CA
    "re: glitches with Wifi Shield, are you using UDPx3, that is the most reliable and fastest."
  • Thank you so much !! let me try.
  • Sorry, I got your ideas and try it, but it still give me the glitches, do you have any other ideas for avoid the glitches?


  • wjcroftwjcroft Mount Shasta, CA
    This is a Cyton with Wifi Shield? How well does the Cyton work with OpenBCI_GUI? Is it possible that your glitches are being introduced by the software you are using? Have you tried WITHOUT the shield, with the GUI. Then adding the shield with the GUI? Are the glitches showing in the GUI window?
  • Yes, it is a Cyton with WiFi Shield, if I take off the WiFi Shield and use the Bluetooth model, the glitches will lost. But the sample rate is only 250Hz, it is not enough to me. I also try different GUI and OpenBciHub release, the glitches is the same, but when I look the data by GUI window data stream, I found that it has not the glitches, so I want to know how you to do that, do you use any filter ?

  • wjcroftwjcroft Mount Shasta, CA
    I don't understand your statement:

    "I also try different GUI and OpenBciHub release, the glitches is the same, but when I look the data by GUI window data stream, I found that it has not the glitches, so I want to know how you to do that, do you use any filter ?"

    You say that the GUI time series widget "has not the glitches." But before that you say "...the glitches is the same...".

    Which is it? Are you using LSL? How are you producing your graph? Are you sure the glitches are not introduced with your graphing or interface to the LSL library?
  • retiututretiutut Louisiana, USA
    edited July 2019
    There has been an open issue on GitHub for some time. It is extremely difficult and now marked as "in progress". This is why there is a disclaimer on the WiFi shield.


    @profeell You can avoid these glitches by not using the WiFi shield. If you get packet loss using Cyton+Dongle, it will still show up as a "noise spike" until the above issue is resolved. There is more packet loss with WiFi shield, so you get more "noise spikes".
  • Thank you, I got it. But I need 1000Hz sample rate data, if I take off the WiFi shield, how can I get the 1000Hz sample rate data. The 250Hz sample rate is not enough to EEG researching, so I hope you can solve the problem, even you made new Wifi shield board with new chip. If you can launch new product for solve the problem, I would like to buy it. Sorry my English is no good, but I hope your product will be better and better. 

  • retiututretiutut Louisiana, USA
    Thank you for your comment. We are working on this issue, new products, and ways to improve the user experience.
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