Ganglion to BrainBay

ElliotMElliotM United States
in Ganglion
I have downloaded BrainBay (master) from GitHub (4/21/2019) and a fresh install of OpenBCI (which apparently includes the OpenBCI Hub). Although there is no Hub application at the location specified in the BrainBay settings, the Hub is open because I launched the OpenBCI GUI so BrainBay seems to be able to find and connect with the Ganglion. In a simple design I am able to see values in the Oscilloscope, and they change when I touch electrodes, however they do not represent anything sensible. Without touching the electrodes I see a sawtooth wave with an approximate period of 1Hz. When I touch any of the electrodes the values kind of drift up and down but remain in a sawtooth. I have gold cup electrodes connected to the Ganglion at D_G, REF and 4. All the switches for the electrodes have been set to the down position.  

Would someone please post working step by step instructions for connecting the Ganglion to the new BrainBay release for Ganglion? The OpenBCI instructions page seems to refer only to the older connection method for a different board. 

Comments

  • wjcroftwjcroft Mount Shasta, CA
    Elliot, hi.

    Chris is going to upload a new 2.3.2 installer shortly. The current 2.3.1 installer does not show the correct default location for the Hub. That setting in Options / Applications Settings should read:

    C:\Program Files\OpenBCI_GUI\data\OpenBCIHub\OpenBCIHub.exe

    Which is where the Hub lives. The old location shown was the case for earlier Hubs.

    As far as your sawtooth, my only hunch is that you are seeing some kind of weird interference between the OpenBCI GUI connecting to the Ganglion, simultaneously with BrainBay? I don't see any sawtooths here. I suggest closing the GUI while you are running BrainBay. BrainBay will then start it's own copy of the Hub. And after exiting, it will leave that Hub running in the background.

    What dongle are you using? BLED112 is recommended.

    Regards,

    William

  • wjcroftwjcroft Mount Shasta, CA
    Until the 2.3.2 shows up on the releases page,


    See this issue for a drop-in brainBay.exe (you can copy over the 2.3.1 exe) that handles Ganglion connections a bit more smoothly.



  • ElliotMElliotM United States
    I'm using a BLED112 from OpenBCI. 

    I am already using that .exe b/c I downloaded master from GitHub today and that file is 4 days old. 

    I updated the HUB location in BrainBay settings, closed everything, unplugged/replugged the USB dongle and restarted BrainBay. The Hub started automatically and the rest of the results are the same. 

    Do the Impedence tests do anything? Mine are all red. 

    Here is a screenshot: https://ibb.co/m5JRJm2. The sawtooth is more regular when I launch the design, then after touching an electrode it gets more irregular, however it continues to have an abrupt vertical movement every second or so. 

    BTW: my readings in the OpenBCI GUI are clean. 
  • wjcroftwjcroft Mount Shasta, CA
    I don't understand "I downloaded master". Why not just use the installer / setup that is on the Releases tab? The installer exe does a number of steps. Are you building BrainBay from source? 

    Have you tried connecting a shorting lead between channel and reference or plus and minus channel? That should produce close to zero uV. (Actually more like 13 uV due to DC offsets in the front end.) 

    In terms of your design, you can connect the Ganglion directly to the Osc. (Without the multiplier.) Then right clicking on the used Osc pin, you can set the scale, per pin.

    When was this Ganglion purchased? The fact that the GUI sees this just fine, must mean your BrainBay installation is not correct. What OS are you using? What is the installation directory for BrainBay?

    Thanks,
  • ElliotMElliotM United States
    I downloaded master from GitHub for this very reason. The release is 13 days old and master is 4. I did not know that anything else was done during installation. 

    The Ganglion is brand new and delivered this week. I am using Windows 10. I installed in D: and I adjusted the Hub reference in BrainBay to be the correct location in D:

    I separated my wires so they are not a ribbon. That may have helped. 

    I haven't connected a shorting lead. Is that the same thing as throwing the switch for the channel? 

    I removed the multiplier and adjusted some settings in the oscillator. Maybe there is some 60Hz noise or something. I am trying to get a nice clean ECG reading like I can get in OpenBCI GUI. My original oscillator settings were providing static (vertical lines as the values swung way above and below the display range). so I added the multiplier. The default oscillator settings are: drawing interval: 1, display gain: 100. I seem to be getting more valid readings by adjusting the oscillator settings to 5 and 1, but it's not a clean QRS wave. 

    What do you see with just one channel connected and the default oscillator settings?  

    I'll try unintalling BrainBay and reinstalling then replacing the .exe. 

  • ElliotMElliotM United States
    edited April 2019
    I have had some luck with a modified EEG design. Can anyone describe how to display the raw EEG signal for a channel in a BrainBay oscilloscope panel (so it looks like the OpenBCI GUI Oscilloscope)? 

    Here's a pic of a design I modified from the sample designs. This is a single channel forehead EEG (with D_G and Ref channels attached to the earlobes, the Ganglion switches in the *down* position). The left oscilloscope is the Alpha, the right *should be* the raw values coming off the oscilloscope. I'm not sure why the raw oscilloscope values seem to be oriented around -900 uV. I must have something misconfigured.  

    Here's the oscilloscope in OpenBCI GUI:
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