Issues with Breaking while loop in Appdesigner.

I need to break while loop - which reads a sensor value - I want to break the while loop when pushbutton is pressed.

I tried using "Tag" handle in pushbutton to break the loop - it breaks loops before pushing the pushbutton.

Error:

Error using matlab.ui.control.Button/get

Unrecognized property Value for class Button.

Error in IRgauge/ReadDistanceButtonPushed (line 36)

stop_state = get(app.CLOSEButton,'Value');

Error using matlab.ui.control.internal.controller.ComponentController/executeUserCallback (line 382)

Error while evaluating Button PrivateButtonPushedFcn.

Code for reading sensor in appdesigner "Code View"

        function ReadDistanceButtonPushed(app, event)
            CommPort = serialport('COM30',9600);
            while 1
                R = readline(CommPort);
                R = str2double(R);
                app.DISTANCEGauge.Value = R;
                drawnow();
                stop_state = get(app.CLOSEButton,'Value'); % to break infinity loop
                if stop_state
                    break;
                end
            end
        end
        
        % callback function breaking infinity loop
        function CLOSEButtonPushed2(app, event)
          close all; clc; delete(instrfind);
        end

[Mario Malic]

Try this,

function ReadDistanceButtonPushed(app, event)
    CommPort = serialport('COM30',9600);
    while 1
        R = readline(CommPort);
        R = str2double(R);
        app.DISTANCEGauge.Value = R;
        drawnow();
        if app.CLOSEButton.Value; % to break infinity loop
            break;
        end
    end
    % Clean stuff here
    close all; clc; delete(instrfind);
end

[Ameer Hamza]

The problem is that the push button in MATLAB does not have a property named 'Value', so the statement

app.CLOSEButton.Value

will cause an error.

[Mario Malic]

I have to work on this part of carefully reading the whole question. That's correct, push button does not have the Value property. The better solution would be State Button, which has one, thus having only one button on UI.

[Ameer Hamza]

I agree, state-button seems more suitable for the thing OP is trying to do.

[Franck paulin Ludovig pehn Mayo]

@Ameer Hamza hello , please could you have a look on the link below.

https://de.mathworks.com/matlabcentral/answers/1625350-how-to-get-mouse-position-without-a-click-event-on-appdesigner

Answer 1

[Ameer Hamza]

Try the method in the attached app.