How do I jump out of an endless loop in App Designer?

Hi!

I created 3 buttons with App Designer to control a stepper motor, where

Button 1: Moves forward

Button 2: Moves backward

Button 3: Stops everything

Now, I tried to realize it with an endless loop, so that if Button 1 is clicked, it will move forward endlessly. My callback functions for button 1 and 2 then look like this:

app.check = 1;
app.check = 0;

while app.check = 0
    %some functions to move the motor
    if app.check = 1
        break
    end
end

Here I set an app property app.check. This should be set to 1 whenever a push button is pressed to then jump out of a previous loop via the if line.

Now, as it is an endless loop, pressing the button won't change the value of app.check, as this task is only queued and won't be set until the endless loop ends.

And exactly this is my problem. Is there any other opportunity, to just let callback 1 run until something else is pressed?

Much regards and thank you for reading!

Answer 1

[Geoff Hayes]

Hieu - try putting a drawnow or pause in your while loop so that it can be interruptible (which should allow the push button callback to execute and so change the state of the check variable).

[Hieu Philip Hoang]

Thank you very much! "drawnow" before the if works

[madhan ravi]

+1