Delay function to slow down while loop

Hey guys. I'm new to MATLAB and I've got a question to ask. I am currently doing up this UI which includes a code which is shown below.

% --- Executes on button press in Start.
function Start_Callback(hObject, eventdata, handles)
% hObject    handle to Start (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)
global s brightness a t;
t = 0.1
a = 1;
readasync(s);
while (a == 1) 
  brightness = str2double(fscanf(s, '%s', 8));
  set(handles.brightness, 'String', num2str(brightness));
  disp(brightness);

     if brightness < 87
        if brightness < 44
           fprintf(s, '%s',1);
        else
           fprintf(s,'%s',2);
        end
     else
        if brightness < 130
           fprintf(s, '%s',3);
        else
           fprintf(s, '%s',4);
        end
     end
     if(a==0)
         break;
     end  
    pause(1/10);
  end

As you can see, I am currently using a pause function to delay the while loop. However my mentor in college suggested that I use tic toc instead of pause to delay the loop. I do not know how should I go about with it. He has given me this function but I do not know how to implement it. Any advice?

   function delay(t)
   tic;
   while toc < t
   end
   end

Answer 1

[Walter Roberson]

pause() is the better choice. It gives a chance for other things to happen, and it gives up control of the CPU so it does not need to run as hot. Using tic/toc requires continuous computation. Please see https://en.wikipedia.org/wiki/Busy_waiting