connecting Processing GUI to an external hardware via serial port

Xp0Xp0
edited March 2018 in OpenBCI_GUI
For a couple of weeks I have been looking through other projects in which control of external hardware using brainwaves was achieved, most notably Chip's hexbug and shark projects:  http://eeghacker.blogspot.com/2014/06/controlling-hex-bug-with-my-brain-waves.html 
I have been using the ganglion board and a device running windows 10 which does not appear to link as smoothly to the board as a Mac can. 
Using the Ganglion as a COM port to be used with arduino code did not appear to work, 
so I ended up turning to the Processing GUI which appeared to be the means of connecting to the board which worked. The Processing IDE appears to be the best means towards customizing what you can do with the boards output, most prominently in the widget's ability to be fully modifiable (for example the Focus widget) not to mention it can be linked to an arduino or other external hardware connected via serial ports.

My question is, how would one go about stream recorded data in real time from the GUI to an external wired device via serial port on windows?




Comments

  • retiututretiutut Louisiana, USA
    In the current GUI, use the networking widget set to Serial data format. Fill in the data of your desired serial port and stream live or recorded data.
  • Xp0Xp0
    Wow. Thanks for the info! Cannot believe linking the GUI to serial was that simple.

    Now, it is to my understanding the baud rate for an arduino which I'm using should be around 9600, this doesn't not appear to be an option on the current widget, any suggestions on how to modify that?
  • retiututretiutut Louisiana, USA
    That was the only other thing I was going to mention: Baud rate. 9600 is on the slow side for Arduino (reference) , but I would stick with one of the rates offered by the OpenBCI GUI because the communication rates play nicely with how data is processed on the hardware level on Ganglion and Cyton. I would recommend editing whatever code you are using with your Arduino to increase the Baud rate.
  • Xp0Xp0
    Additionally, is there anyway to manipulate data being streamed from OpenBCI GUI to the arduino so that the arduino itself can generate an output? Im a little lost in terms of how I can do anything with streamed data with arduino IDE (i.e. Measured alpha waves give value "true" which can be taken by arduino code which then outputs a desired function)
  • retiututretiutut Louisiana, USA
    That involves programming within Arduino IDE and then uploading to your Arduino device.
  • wjcroftwjcroft Mount Shasta, CA
    edited March 2018
    @Xp0, hi.

    Generally, experimenters do their signal processing on the laptop, since it has much advanced signal processing capabilities and libraries. Then send various 'commands' of your own devising to the Arduino over the serial port. 


    William

  • Xp0Xp0
    Sounds like an interesting concept. 
    Would you care to elaborate?
    My end-game here is to be able to manifest measured EEG using the ganglion into physical hardware, a task which seems well achievable with something such as an arduino.
    I have experience coding in the arduino environemnt so the fact that the OpenBCI hardware / software is arduino compatible was fantastic.

    By signal processing the data, do you mean sending the streamed data to other programs which then send outputs to arduino code?
    Or is there a method to create a value directly in the processing code that can be sent directly to arduino code which acts on a "command" given?

    Thank you for your help.
  • retiututretiutut Louisiana, USA
    edited March 2018
    The networking widget does send the information directly to the Arduino over serial.

    @wjcroft is correct, a laptop running any number of programs will process signals better than whatever you can write in Arduino.

    As previously stated, you need to program the Arduino to perform an action regardless of where a signal is processed. Creating a new value within the OpenBCI GUI involves creating a widget. There are resources available on creating a widget and all code for the OpenBCI GUI is open source on Github.
  • wjcroftwjcroft Mount Shasta, CA
    There are multiple ways to do this. I believe Chip in his hexbug and shark projects, modified the GUI to (for example) place thresholds on the values in the FFT bins. So if he was detecting alpha, he would be watching the FFT bins from 8 to 12 hz. Once those crossed a certain level for a sustained period of time, he would then send a serial command to the Arduino that was controlling the hexbug or shark.

    A more flexible approach with rapid prototyping can be done with VPL, Visual Programming Language environments such as BioEra, LabView, OpenViBE, Max / Puredata, etc. These frameworks let you setup chains of signal processing elements such as filters or ffts, thresholds, and provide feedback. Some of these VPLs support output to serial ports or calling external functions written in Java or C; which could then output arbitrary text commands to a serial port. For example if you were trying to control an LED (on the Arduino) to turn on or off, the serial commands might look like "L0" or "L1".

  • Xp0Xp0
    Thank you so much. I'll work a bit the concepts and see how that turns out.
  • Zimmerman99Zimmerman99 Connecticut
    Hello! I understand that late, I apologize. But who can be useful again. I’m sending data from a com port via the ethernet using Serial over Ethernet. And it is possible to analyze and intercept data in real time using software to analyse serial port. I have been using them for a long time and I have enough of their functionality.
  • Xp0Xp0
    Hello Zimmerman99,

    I actually ended up using a similar software myself to analyze serial data a couple of months back. Good recommendation nonetheless!

    For any users interested in connecting their OpenBCI to an arduino via serial port (usually its to test out the focus widget as that is a decent starter project),
    the networking widget must be connect to serial com port which the arduino is on. If you are connecting the focus widget, the GUI literally sends the string
    "true"
    or 
    "false"
    over the serial port. 
    In case that wasnt clarified to any folks newer to neurotech, that is what the focus widget sends.

    Onwards,

    The serial over ethernet communication looks very interesting, I'll make sure to try that out with the BCI in the near future!

    I'll make sure to make a more complete explaination on getting the arduino to read longer strings and act on them in a later post


    Happy New year folks!

    ~ XP0





Sign In or Register to comment.

© Vanilla Keystone Theme 2026