Matt16
Matt16
About
- Username
- Matt16
- Joined
- Visits
- 55
- Last Active
- Roles
- Member
Comments
-
Would this work as an opto isolator? https://www.amazon.com/Gikfun-OPTOCOUPLER-PC817C-Arduino-AE1143/dp/B01JG8EJVW/ref=sr_1_7?crid=3NTFRVVIH30VV&keywords=opto+isolator+arduino&qid=1670701703&sprefix=opto+isolator+arduino,aps,84&sr…
-
Hi William, Could you explain briefly some of the reasons for your suggestions? * You say keeping the trigger signal within the biosignal voltage range "helps" the compression. How exactly does it help? What issues might I face if I don't st…
-
Maybe with high-frequency stimulation?
-
I've heard from other researchers that they needed shielding with OpenBCI, so I am curious in which circumstances one does or does not need shielding.
-
Ah I understand. Maybe the stimulus box will have to have multiple layers.
-
Thanks for your feedback as always.
-
Actually, I meant just wrapping the Arduino in foil. It is physically separate from the OpenBCI.
-
For now, I will try redoing the experiment with an eye mask on. Do you think that not seeing peaks there would be a good enough verification?
-
Hey William, Despite this issue I am seeing a very high peak at the expected frequency for my SSVEP experiment and want to move forward. I see these high peaks both for flickers generated from the Arduino and flickers generated from an .mp…
-
Yes, that's correct. I don't know why my sample rate is perfect sometimes and not other times. But I largely suspect it has to do with the bluetooth connectivity.
-
The 190Hz is from dividing the number of samples from the time elapsed. There is no packet loss in the GUI. I am ignoring the timestamps. Please see the conversation on slack I had here: https://openbraintalk.slack.com/archives/C01053V5W6N/p16659…
-
The samples came in at around 190Hz, which explains why the peak is slightly below 12Hz. This is a bluetooth issue which I have discussed with others that affects Macbook users.
-
I just saw crystal clear SSVEP for the first time from my own recording! And that was from a computer screen video stimulus, so there's no possibility of it being caused by the arduino (it was unplugged).
-
I just went to check the EEG Setup guide again to make sure I didn't miss anything. Turns out I missed the point about switching from differential mode to REF mode. After switching all 4 of the switches, my signal looks amazing. In the OpenBCI GUI I…
-
The OpenBCI board is on my desk next to my computer and monitor. Yes, there are power cords around. Maybe this is the issue. Here is the test you are asking for. The arduino is disconnected and off. I start closing eyes right when the stream star…
-
Sorry for the miscommunication. By "everything is good", I just meant that I had corrected the mistake in a previous post where I previously had reported the wrong data.
-
Now what I am wondering is: 1. Does my data look relatively normal, or are there atypical noise patterns? 2. Which, if any of these would be logical steps to take? - Creating some sort of EMF shielding around the Arduino and/or somehow the Op…
-
Note that I made a mistake earlier and mixed up some data. I edited the post a few minutes after posting it. Everything is good as of now.
-
Finally, I took your advice to do an SSVEP experiment with the Arduino disconnected. Here, everything is the same as the experiment above except: * The arduino is disconnected and turned off * The 12Hz stimuli is from a video on my computer sc…
-
Next, I have a new SSVEP recording. I programmed the Arduino to do sinusoidal stimulation like you suggested (it was way more comfortable to look at). Like with the closed-eye alpha test above, the power spectrum is only useful when the bandpass fil…
-
I have recorded a closed-eye alpha test directly from OpenBCI GUI. All 4 electrodes were around Oz and impedance was below 50 for all of them. The data is here: https://drive.google.com/file/d/19iKIgrWK8e3rsp0mBPAEv88feInV-GCO/view?usp=sharing Th…
-
Hi William, Thanks for the ideas. The previous threads that you mentioned first, am I correct that those are specifically regarding issues with flicker stimuli coming from a computer monitor? If so, I think that this type of issue is avoided b…
-
Link to data and code
-
Wow, thanks as always for the help William!
-
Hi William, Thank you, your suggestion worked completely! The new OpenBCI board I got did not come with a second dongle (I don't think they come with dongles, right?) But I found another lying around that I purchased previously. Simply switchi…
-
Just did and they figured it out. All I had to do was leave "Mac Address" blank. I mistakenly thought mac address and device name were the same. It works now. Thanks again.
-
I'm guessing this is not the issue since I get the same error even if I run with sudo?
-
Wjcroft, I'll head straight to slack if the solution is not obvious to you. Thanks for your help.
-
Another step in the right direction, thanks! The correct one seems to be /dev/cu.usbmodem11 Now rather than hanging, I immediately get an error: [2021-12-20 15:11:24.307] [board_logger] [debug] use dyn lib: /Users/matt/miniconda3/envs/eeg/lib/p…
-
Oops, I forgot all about that. Ok, I used ls /dev/tty.usb* and the result was only a single line: /dev/tty.usbmodem11. So I replaced COM3 with that. Next, I used "Ganglion-C97F" (from OpenBCI GUI) as the default value for mac-address (is that the r…