stream selct, blocking a stream, display ASCII, time stamp

[barten6]

Hi there,
getting more and more into the secrets of OV, I still have some open issues - I don't find answers for them in the documentation:

• 1. how can I select 1 Signal stream out of 2...4 for further processing (for instance if I Need to Switch back and forth between an acquisition Client and a GDF file Reader) by using the kbd-stimulator ?
  2. does any box or combination of boxes provide the functionality of simply Switch between letting through or blocking a Signal stream ?
  3. is there any box or combination of boxes that allows to Display an ASCII-text, coming from USB, in a seperate window (not in the log manager !) in real time Operation ?
  4. how would you insert a time stamp, coming from USB, during recording by the GDF-writer ?
  5. is there any box or combination of boxes that converts signals to Stimulation and vice versa ?

I would appreciate any Feedback..
rds
Peter

[jtlindgren]

Hello Peter,

For 1, 3 and 5, I am afraid these would need some coding. Sometimes when people want to get some custom, specific functionality quickly, they do with it the python box, writing a small script for the purpose. However, it could be difficult to get python based visualizations work on windows and openvibe, so I'm not recommending this for the text display. In any case the last one should probably be done with an external application, as stimulus displays in general. This will allow them to run at their own pace and not be limited by the speed or frequency or the real time capabilities of the processing loop of designer.

About 2, isn't it possible just to use the stream switch box with two outputs, thinking of the other output as a sink or a null?

For 4, this should probably be done by making a small external application that sends this time stamp as a stimulus to the acquisition server. The GDF writer should then insert this stimulus to the file.

http://openvibe.inria.fr/send-stimulati ... on-server/


Happy hacking,
Jussi

[barten6]

Hi Jussi,
thank you for your reply!
Concerning issue #4 : very good idea, thanks again!I'll try it out tomorrow.
To #1, 3, 5: I'm surprised- those functions are really not very digressive, and you find them in much less sophisticated systems such as BrainBay... maybe that someone already worked on that for OV...?
To #4: Yep, I agree! The bad thing is, that I didn't find out so far, HOW to send stimuli of different kinds (i.e. stim_A, stim_B etc) to the acquisition server... are you aware of a tutorial which clarifies the basic idea of this?
All the best
Peter