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Signal Processing

Posted: Sun Nov 29, 2015 8:12 am
by tamulev2
Hi!

I have just started using OpenVibe and for my small project I have to build a box, which takes processed signal of Alpha wave range and issues the notification as the trough of the signal is found. The problem is that I don't have any idea how matrix, which is signal input in my box, looks like, how do I access particular data inside, how does that data look like? Is there an easy way to distinguish trough and issue notification? The way I imagine that is to obtain data in chucks which correspond to alpha wave frequency process the data and find trough which is probably some negative value in matrix. Moreover, once that is found I can use Stimulation listener to send notification to other software (Lab View). Does that sound reasonable?

Thank you very much and have a nice day!

Wishes,
Laurynas

Re: Signal Processing

Posted: Mon Nov 30, 2015 10:57 am
by nfoy
Hi,
You might want to have a look at and get inspiration from the scenario neurofeedback.xml located in dist/share/openvibe/scenarios/bci-examples/neurofeedback.
This scenario shows how the get the beta power from brain signals.
For communication with external applications, I suggest you to look at the TCP Writer box for instance.

Re: Signal Processing

Posted: Wed Dec 02, 2015 7:42 pm
by tamulev2
Hello,

Thank you so much for your advice, the TCP writer is going to be really useful. I am developing a new algorithm at the moment and rebuilding solution every time takes ages is there any other way I can test/observe the changes in my code? Thank you very much and have a nice day.

Best wishes,
Laurynas

Re: Signal Processing

Posted: Fri Dec 18, 2015 6:39 am
by tamulev2
I figured out the build set up. Now I have been struggling with TCP writer, which seems to write data to specified port but it is encoded and I cannot obtain it as I am trying to perceive data using LabView which gives me ton of errors. I have not encountered protocol communication before so maybe you know any helpful simple examples how to extract the information written by TCP writer? Thanks .

Re: Signal Processing

Posted: Fri Dec 18, 2015 12:49 pm
by jtlindgren
The first step is to look at the documentation of the box in box documentation section of the openvibe web doc, and the associated example code bundled with openvibe source code, see in applications/examples/openvibe-to-tcpip/.


Cheers,
Jussi