SRB2 off in OpenBCI, how to process it in txt/csv files?

skiria8 · February 2018

I'm trying to read in Matlab the raw data collected with OpenBCI. In OpenBCI I turned SRB2 Off as I don't use a common reference. The signal I visualize is as expected.

However, when I read the saved data from the txt/csv file, I cannot get the same signal (even after applying notch and 1-50Hz bandpass, the same configuration in OpenBCI). How should I process the data to disable SRB2?

I only use 3 electrodes for EMG data. Bias in the forefront, N1+ and N1- on the cheek. One of those acts as reference.

wjcroft · March 2018

Skiria, hi.

What happens when you exactly follow the tutorial steps for collecting EMG / EEG / ECG as shown in the tutorial?

http://docs.openbci.com/Tutorials/01-Cyton_Getting Started_Guide#cyton-getting-started-guide-v-connect-yourself-to-openbci-3-connect-your-electrodes-to-your-head-and-body

Does the txt file produced this way, look ok in Matlab? If so, then perhaps you don't need to alter the default board settings.

William

pushtheworld · March 2018

There is a possibility that your filter parameters are different which could produce a different looking signal.

skiria8 · March 2018

Thanks so much for the responses. I finally figured out the problem. The signals were correctly collected but the filter I was using in Matlab was not filtering correctly. After correcting it, I got a similar signal.

SRB2 off in OpenBCI, how to process it in txt/csv files?

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