GUI_5.0.2 Serial Port
nejemia
argentina
in OpenBCI_GUI
Dear All.
Extremely happy and excited to try the new version of GUI 5.0.2.
However, I need a piece of advice on how to connect to my CYTON using a direct Serial connection since I am no longer using RFDuino dongle.
The previous version allowed me to use (for instance) COM10 and worked, but with this version, I can't.
If you can help me to add the option of using any COM port will be very appreciated.
Also, if I need to run the GUI from processing IDE, please let me know which version and what new libraries I must to add in order to run the 5.0.2 version and also to compile a stand alone code for my colleagues.
All the best.
Nelson
Comments
@nejemia Glad to hear you are enjoying 5.0.2. This is now a great version to build off of!
This is a relatively easy fix. We are only displaying com ports with a matching cyton dongle product name. You can tinker with the code here to make sure your option shows up:
https://github.com/OpenBCI/OpenBCI_GUI/blob/8aa963350f6702e2bcfb5c95db3080148fa0e0f7/OpenBCI_GUI/ControlPanel.pde#L591
Re: libraries
- Simply clone 5.0.2 from Github and copy all libraries to Processing/libraries folder.
If you really want to be a rockstar, use the developer setup that we use! VSCode is much better than the Processing IDE, and you can view multiple tabs side-by-side. Here is the link:
https://github.com/OpenBCI/OpenBCI_GUI/wiki/Developer-Setup
Hope this helps!
RW
Thank you !
It is working now.
However, I can't export the application to run in stand alone mode.
See the problem:
Can't post image nor file....
Maybe try restarting Processing?
Yeap. Restarted and working like a swiss watch.
Question. Per Texas Instruments, the ADS chip 1299 SRB1 pin is connects to ALL the Negative INP of the channels.
Why then the GUI offers the connection of SRB1 for each channel? It seems to be a "non-sense". A shingle button for toggling SRB1 ON/OFF will be perfect.
This is confusing.
I agree SRB2 can be assigned to any Positive INP of each channel but SRB1?
Well, just curiosity.
Nelson, hi.
The default configuration settings used by OpenBCI on Cyton, connects SRB2 as a 'bus' (reference lead), to all INxP pins (IN1P, IN2P, ..., IN8P). This then allows the INxN pins to act as EEG channels. SRB1 bus is by default NOT used or connected.
William
Hi William.
Yes, this is clear.
However, lets assume I want to use INxP as the electrode input while connecting all the INxN as a reference electrode.
This can be accomplished disconnecting SRB2 from all INxP inputs, and connecting the Reference Electrode to SRB1.
The interface has 8 switches for SRB1 but Texas Instruments states that SRB1 is common to all INxN inputs.
So, the question is: why the GUI offers 8 switches to connect SRB1 while actually one is required to make ALL the INxN common reference electrode?
Do I explain myself, sorry for my poor grammatical skills... Would it be in Spanish, my skills are notably better.
PD. Next question will be about BIASes.
Why even bother?? Just invert the signal in software.
You probably have a valid point regarding the GUI Cyton hardware settings page. But very very few people need or use the SRB1 feature. Mentioning Richard @retiutut. I assume turning on ANY of the SRB1 switches, is the same as turning them all on. Likely this was just done to simplify the user interface operation.
Well, let's say I chain the INxN to the INx+1P in order to make a sequential Bipolar Montage. Using SRB1 instead of SRB2 I can change from Bipolar Montage to Referential Montage just changing this BIT. So using SRB1 as Reference electrode is quite interesting, much better than using SRB2... So, the question is: according to manufacturer, SRB1 is controlled by MISC1 register and putting a "1" routes ALL the INxN to SRB1, so, why the GUI shows one switch per channel to connect INxN to SRB1 while all INxN are routed to pin SRB1 at once when setting MISC1 register? It is misleading, a single button would be required to route ALL the INxN to SRB1 pin.
I get your question. Richard may be able to answer. I continue to feel that SRB2 default works great for 99.99% of OpenBCI users. Those that need to use differential channel montages (like bipolar), just turn off SRB2 for those channels. The reason the firmware was setup this way, is that using SRB2 as default reference gives more flexibility in how the channels are configured. Even through SRB2 buses the INxP pins.
BTW, I changed the default in the firmware. Now, default for me is SRB1 off, SRB2 off and NO BIAS. But SRB1 actually is very powerful. SRB2 seems very interesting for selecting any electrode as BIAS. In reference to hardware, I saw you have BIAS_IN and BIAS_OUT connected together and the BIAS external filter network composed of R5 and C1 are at the output of the BIAS pin.
According to manufacturer, this is a mistake, the filter network should be between pin 62 and pin 63 of the ADS1299.
So, BIAS can not be used as it is with the CYTON. That is the reason I set BIAS OFF for all channels as default, not having BIAS available makes the board propense to interferences.
Please, correct me if I am wrong on that.
I believe that Joel Murphy (the Cyton designer), was trying to follow circuit examples used in the TI development board. So you might check that out to see what was used. The idea with Bias injection is to try to counter mains interference with a 180 degree out of phase component. In EEG, I've heard that it makes sense to place Bias/Ground on the midline, to more evenly reach both hemispheres. Many EEG caps (such as Electro-cap) have an electrode position at AFz, which frequently is the Ground point.
Yes. The design is based on TI dev board. I think the error was introduced on the PCB design due to a mistake in the .sch drawing.
It is important for all the people using the CYTON to double check if the mistake is there because trying to use the BIAS function with the configuration resulting from this mistake will give unexpected results, and more than this, noise can not be eliminated.
Please, double check this and let me know. If no BIAS is used at all, then, no problem, but I don't know how this abnormal configuration can affect the functioning of the ADS1299.