Arduino support package send two value at the same time to different port

I need to trigger EEG and fMRI at the same time by a visual stimulation I wrote in matlab. I can use the arduino support package to trigger trigger to the EEG system sychronzing the visual stimuli and EEG recording, but I also need to trigger the fMRI scanner. I am thinking connect two arduino boards to my computer via different ports and send two triggers to two ports respectively and simultaneously. How can I do that?

I wrote the code below to synch EEG and visuals stim.

P.S. the visual stim were writen using the VisualStimulus toolbox version 1.0 by Michael Beyeler.

a = arduino('com3','uno'); % Create an adrduino object

f = figure; f.WindowState = 'maximized'; % max the figure window

for deg = (0:7)*45

blank = GratingStim([300 500],'k',20,deg,[1,1],0.1);% generate a blank pic

blank.plot % plot the blank picture

grating=GratingStim([300 500],'k',20,deg); % generate stimuli

writeDigitalPin(a,'D4',1) % write to EEG to start recording

grating.plot % plot the stimuli

writeDigitalPin(a,'D4',0) % write to EEG to end recording

end

clear a % delete the arduino object

Answer 1

[Pratik]

Hi Fan,

As per my understanding, two arduino boards are to be connected to a computer via different ports and two different triggers are to be send to the ports separately.

This can be achieved by creating two Arduino objects. "parfevalOnAll" can be used to run an initialization on each worker that creates an arduino object and stores a reference to it .

Please refer to the following MATLAB Answer which shows how to identify a worker:

www.mathworks.com/matlabcentral/answers/30294-identifying-lab-id-within-a-parfor#answer_38822

Also, please refer to the documentation of "parfevalonall" for more information on running function on all workers in background:

https://www.mathworks.com/help/matlab/ref/parfevalonall.html

I hope this helps!