Psychtoolbox KbQueueXXX functions in Ubuntu

Dear members

I am having a very difficult time using KbQueueXXX functions (i.e., KbQueueCreate, KbQueueStart, KbQueueCheck, KbQueueRelease) to record key presses, kept bumping into errors while following some pretty old step-by-step instructions (e.g., Source One and Two listed at the very end of this post).

I tried to read through the psychtoolbox documentations but still confused with the information presented.

Some very basic questions such as

e.g., should I call

PsychHID('KbQueueStart', device) 

or

KbQueueStart(device) 

to look for keypresses?

I was also wondering whether there is any working demo scripts or more recent sources/ tutorials that I can learn from.

Thanks in advance!

My script:

%%create the Queue device and specify the allowed keys 
device =7; 
keys=[45 46];
keylist=zeros(1,256);
keylist(keys)=1;
KbQueueCreate(device,keylist);

    ...
        
KbQueueStart(device); % look for key presses within a specified time limit
    while TimeOut == 0
       [pressed, firstpress] = KbQueueCheck(device); %check response 
       if pressed
           if        firstPress(45)>0
               ...
                TimeOut = 1;
                break

           elseif     firstPress(46)>0
               ...
                TimeOut = 1;
                break
           end
       elseif TimeInLoop > 10
               ...
                TimeOut = 1;
                break
       end
    end
KbQueueRelease(device);

Error msg presented :

Error using PsychHID
Usage:

[keyIsDown, firstKeyPressTimes, firstKeyReleaseTimes, lastKeyPressTimes, lastKeyReleaseTimes]=PsychHID('KbQueueCheck' [, deviceIndex])

Error in KbQueueCheck (line 61)
  [pressed, firstPress, firstRelease, lastPress, lastRelease] = PsychHID('KbQueueCheck', deviceIndex);

Error in myscript (line 465)
           [pressed, firstpress] = KbQueueCheck(device); %check response

References

Source One

http://cbs.fas.harvard.edu/science/core-facilities/neuroimaging/information-investigators/matlabfaq

Source Two

ftp://ftp.tuebingen.mpg.de/pub/pub_dahl/stmdev10_D/Matlab6/Toolboxes/Psychtoolbox/PsychDocumentation/KbQueue.html

the principle seemed to be

1. KbQueueCreate: create a list of keys
2. KbQueueStart: start “waiting” for keypresses
3. put KbQueueCheck: put this in a while loop to look for specific key presses
4. KbQueueRelease : end the “wait”

Software environment

ubuntu 20.04.1 LTS

matlab 2019b

psychtoolbox 3.0.17