Matlab GUIDE - Change color while loop is running?

Hi,

I'm trying to simulate a low battery scenario in matlab using GUIDE. I was wondering how to get the GUIDE to pop up with a green box (representing an LED), run a loop, then the "LED" turns red once the loop gets to a certain point.

I'm able to do this once I press a pushbutton, but how can I simulate this without pressing the button? Here's what I have:

if true
% --- Executes on button press in pushbutton12.
function pushbutton12_Callback(hObject, eventdata, handles)
% hObject    handle to pushbutton12 (see GCBO)
% eventdata  reserved - to be defined in a future version of MATLAB
% handles    structure with handles and user data (see GUIDATA)

battery=50
  for time=1:100
      while battery>0
      battery=battery-2
          if battery<20 && battery>0
          set(hObject,'BackgroundColor','red')
              set(handles.Screen,'String','Low Battery. Plug in Charger')
          else
          end
      pause(0.1)
      end
  end

end

Any ideas on how I can do this?

Thanks for your time.

Answer 1

[Joseph Cheng]

So.... you can use timer which if used properly you can accomplish what you want.

Code to get you started %i inserted this into the openfnc portion

     tic;
      handles.timer = timer(...
          'ExecutionMode', 'fixedRate', ...       % Run timer repeatedly
          'Period', 1, ...                        % Initial period is 1 sec.
          'TimerFcn', {@update_display,handles}); % Specify callback function
      % Update handles structure
      start(handles.timer);

my update_display looks like this

function update_display(hObject,eventdata,handles)
    elapsetime = toc;
    if round(elapsetime) ==10 
        set(handles.pushbutton1,'BackgroundColor','y')
    elseif round(elapsetime) ==20 
        set(handles.pushbutton1,'BackgroundColor','r')
    end

10 and 20 are in seconds... with this you actually use your pushbutton12 that you've already wrote... I think... I'll leave it to you to figure out how to stop and reset the timer.

if you want a better example of timer you can go see refresh gui data display

[thebasher]

Much appreciated, I would have never considered the timer...Thanks so much for your time and help.

Answer 2

[Image Analyst]

Well, how would you like to start the simulation running?

[thebasher]

When the GUI pops up, right after I hit run. I want to loop to start "draining" the battery. So at first, the LED is green, then after a few seconds it'll turn red.

The code I put above does it at the press of a button, but I'd like it to run automatically.

I hope I made sense.

[Image Analyst]

You can put the code in the OpeningFcn to start it running as soon as the GUI is launched. You don't need a timer, unless you want to. You could do it like you had it, with pause(). Though a timer frees up your GUI to do other things if you want other things to happen while your simulation is draining the battery.