GUI red circle indicating connection

I have serial connection. I would like to have a green circle blinking in the screen while connection is on and a red circle while connection is off.

do i need to use axes for that?

Answer 1

[Baltam]

Personally I would do it with axes yes. Below an example of green and red circle depending on parameter x.

x = [0 1];
for i =1:numel(x)
      rectangle('Position', [0.0 0.0 1 1], 'Curvature', [1 1], 'FaceColor', [x(i) 1-x(i) 0]) % with x = parameter
      ax = gca; 
      % remove tick labels
      set(ax,'XTick',[]),set(ax,'YTick',[])
      % make lines of the axes white --> invisible on white background
      set(ax,'XColor',[1,1,1]) , set(ax,'YColor',[1,1,1]) 
      % make axes square to get round circle
      axis square
      pause(0.5)
end

Kind regards,

Baltam

[Daniel]

what is x? how do i link this to axis?

[Baltam]

x is your variable. In your case wether the connection is on or off. You should make axes in your GUI and implement code in your GUI code that checks if the connection is on and then update the axes by updating the variable 'x' first.

[Daniel]

thanks. it works. follow up question: what if i want to make it blink? i know i can make it appear and disappear, but i want this operation to happen while other code is running. is this an interrupt situation?

[Baltam]

I believe you need something like this and adjust the function to make it change the color of the circle to white. I never used it before so good luck. I also read if you are doing heavy caculations the timer will not do its function in the background but it will do its task whenever some time is available.

    t = timer;
    t.ExecutionMode = 'fixedRate';
    t.Period = 1;
    t.TimerFcn = @(~,~)disp('1s elapsed');
    start(t)

Good luck,

Baltam