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• I have a problem with the stability of the connection between the dongle and the cyton board. When I measured EEG for 120 seconds twice, I noticed packet losses for 4 and 11 times respectively. The experimental setup is shown as the image (IMG 372…

  in Distance between Cyton board and Dongle of Ultracortex Mark Ⅳ Comment by Hiroki June 2020
• Oh I'm sorry. I'll check that.

  in impedances, less with pressure; what is normal range? [resolved] Comment by Hiroki April 2020
• Hi William, Thank you for the thread about the impedance ranges. I understand that the range around < 100 - 200 kOhm is good. And > 2000 - 3000 kOhm is not appropriate because the OpenBCI GUI often displays RAILED when the impedance is hi…

  in impedances, less with pressure; what is normal range? [resolved] Comment by Hiroki April 2020
• It is difficult to find a way to reduce the impedance. * I and subjects feel pain when the spiky electrodes touch the skin. * Replacing with the comb electrodes does not solve this pain. * When I rotate the electrode parts to make the electro…

  in impedances, less with pressure; what is normal range? [resolved] Comment by Hiroki April 2020
• Hi William, You are right. Our engineer was wrong. After I switched back the setting to wireless (the original bluetooth), no problem occurs. Thanks.

  in How to avoid packet losses (Cyton, Windows) Comment by Hiroki February 2020
• Actually, my collaborator ( electrical engineer ) did the hack. He connected the dongle and Cyton board as shown in the image: * GND(dongle) to GND(Cyton) * Rest(dongle) to RFRST(Cyton) * Rx and Tx with each other. Actually I use about o…

  in How to avoid packet losses (Cyton, Windows) Comment by Hiroki January 2020
• Errors occur even after a few minutes after the start of recording. The driver version is 2.12.28 and is the current newest: https://www.ftdichip.com/Drivers/VCP.htm The packet losses occur if I use Bluetooth wireless connection.

  in How to avoid packet losses (Cyton, Windows) Comment by Hiroki January 2020
• Oh, yes, sample.channel_data is raw data, not band-pass filtered. I use cyton.py to read EEG data, so sample.channel_data is a list of raw amplitudes at unit uV. I'll add a narrow band-pass filter (31.2Hz +- some Hz) to my code and try again.

  in How to measure impedance using Cyton serial command protocol Comment by Hiroki January 2020
• Hello, The source code of GUI: float impedance = (sqrt(2.0)*dataProcessing.data_std_uV[Ichan]*1.0e-6) / cyton.get_leadOffDrive_amps(); // Subtract the 2.2kOhm resistor impedance -= cyton.get_series_resistor(); My python source code is: imp…

  in How to measure impedance using Cyton serial command protocol Comment by Hiroki January 2020
• Hi William, You might add [resolved] to this thread title but is not resolved. Can you provide additional information?

  in How to measure impedance using Cyton serial command protocol Comment by Hiroki January 2020
• Let me confirm the calculation. I think I should send 'z 1 0 1 Z' to cyton since I use N pin to measure, is this right? After I receive the EEG data, I should multiply the data with -1, since the data is negative upper, is this right? When I turn…

  in How to measure impedance using Cyton serial command protocol Comment by Hiroki January 2020
• What I want to know is, yes, the correlation of the signals from the dry OpenBCI and another wet EEG device. Now I'm doing experiment using wet EEG. My experiment is to measure an ERP. If the OpenBCI can capture the same ERP, I want to replace th…

  in dry vs wet electrodes, quantitative noise & signal quality comparisons Comment by Hiroki June 2019
• I'm looking for research that compare the correlation of the signals simultaneously obtained by a OpenBCI and another research/medical grade wet EEG. I found a paper that compare the amplifiers and shows the signal correlation is very good. htt…

  in dry vs wet electrodes, quantitative noise & signal quality comparisons Comment by Hiroki June 2019
• Hi William, ( Thank you for the reply every time I asked ) My first question is for the Cyton board, not for the Daisy board. Again, does the Cython board do the other *unnecessary processes* over raw EEG data at the limited bluetooth channel?…

  in Daisy averaging of the live stream EEG data from the Cyton board Comment by Hiroki May 2019
• Thank you.I'll use SRB2, BIAS2, and IN1N, and invert the signal.

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki December 2018
• Thank you so much for the explanation.But I'm not familiar with electrical engineering,  I couldn't read the circuit. Let me confirm the function of ADS1299. I read 9.3.1.2 Analog Input and 10.2.2 Detailed Design Procedure of the data sheet. …

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki December 2018
• I moved the electrode of the right ear clip from AGND to BIAS.http://bit.ly/2LnaZAL I measured the auditory evoked potential again, but the waveform is similar to the previous one. http://bit.ly/2CjJV2p I'm struggling with this problem...

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki December 2018
• Ooops I might mistake to connect the right ear clip to the wrong pin. I think this is wrong ( the most right electrode )?. http://bit.ly/2ECSKGW

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki December 2018
• I connected each electrode to ... N1N, N2N???I took a picture -> http://bit.ly/2Bu0zej Is this correct? I referred to http://docs.openbci.com/Headware/01-Ultracortex-Mark-IV to connect electrodes. I'm not sure what is SRB2.

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki December 2018
• Hi, Several months ago, I posted about the polarity of openBCI. I wonder that the polarity might be upside down. When we hear sounds, the auditory evoked potentials are elicited. https://escholarship.org/uc/item/704339ms https://www.ncbi.n…

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki December 2018
• This is another but similar question related to this thread's question.When I do the experiment, I arrange the position of electrodes and conditions between the electrodes and the skin so that the EEG amplitudes at the resting-state measured by the …

  in How to measure the contact quality between the electrodes and the head skin Comment by Hiroki October 2018
• Hi William, Maybe the problem is fixed. I checked the channels and found both channels are set to 20. I changed the one channel to 1 and left the other 20. When I run my program on two PCs at the same time, then I got no error! Thanks a lot!

  in research with 20 EEGs simultaneously in 1 room / record to SD card or Wifi? Comment by Hiroki October 2018
• Hi William, When I use two Cytons, I could not connect to Cytons from my python program. The setting is follows: - PC #1 -> bluetooth dongle #1 -> Cython #1 - PC #2 -> bluetooth dongle #2 -> Cython #2 There are two identical s…

  in research with 20 EEGs simultaneously in 1 room / record to SD card or Wifi? Comment by Hiroki October 2018
• I purchased 2 headsets and 2 cyton boards.Can I use them simultaneously in one room? If the bluetooth signals interfere with each other, how far should I place them?

  in research with 20 EEGs simultaneously in 1 room / record to SD card or Wifi? Comment by Hiroki October 2018
• I wonder that the polarity ( plus and minus ) might be opposite.Does the cyton board's plus mean the conventional EEG's plus?

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki September 2018
• Hi, I have a problem with a bandpass filter. I use a FIR filter with numtaps = 101 and cutoff frequencies 2.0 to 35Hz. The reason of 35Hz is to eliminate 50Hz power supply noise, and 2.0Hz is to eliminate the DC offset and slow DC drift. I can …

  in IIR or FIR filter, order / ERP polarity ? Comment by Hiroki September 2018
• Hi William, The cause was very simple. The first sample is always 0 and the subsequent samples have large numbers, as a result, PSD was strange. When I omitted the first 0, the result was as expected. Thank you.

  in Neurofeedback, OpenBCI Boards, and general getting started Questions & Thoughts Comment by Hiroki September 2018
• I also checked the packet_id(sample ID).It was incremented one by one and there was no warning message, so I think there was no packet(sample) loss.

  in Neurofeedback, OpenBCI Boards, and general getting started Questions & Thoughts Comment by Hiroki September 2018
• Hi, Yes, I'll apply a bandpass filter. I understood that the raw data contains a DC offset of ADS1299 as you mentioned. What I want to say is, the PSD of raw data from OpenBCI_GUI is as expected, even if it contains a large DC offset, while t…

  in Neurofeedback, OpenBCI Boards, and general getting started Questions & Thoughts Comment by Hiroki September 2018
• The images seems to be broken.Here are links to images. https://drive.google.com/open?id=1h6CWPwoKgv4_UFCIWSFuRR28dwiP-rUo https://drive.google.com/open?id=1tibaZg7YwLQfyABfR-AKqZCJ0zgUwprs https://drive.google.com/open?id=11ZTJFSHUEaUapdl4l6z8…

  in Neurofeedback, OpenBCI Boards, and general getting started Questions & Thoughts Comment by Hiroki August 2018
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