how to set exposuretime in appdesigner with EditField?

Hi,

I am trying to change the exposure time with an Edit Field, but I am problem accessing the camera properties wihin the app.

For example I define the camera properties as 'scr', then I set Camera Exposure and other properties when the camera starts.

        % Code that executes after component creation
        function startupFcn(app)
            clc
            delete(imaqfind);
            
            % Create video object
            imaqreset % resettar videoiput
            app.VidObj = videoinput('gentl', 1, 'Mono12');
            
            % camera properties
            scr=getselectedsource(app.VidObj);
            
            % setting the exposure time
            scr.ExposureTimeAbs = 100000; % us  100 ms = 100'000 us
            

But then I want to add some kind of editable field (like EditField) where I can enter a number that will set the exposure time of the camera. Like, ..

            function ExposureTimemsEditFieldValueChanged(app, event)
            value = app.ExposureTimemsEditField.Value; % in ms
            % 100 ms = 100'000us; 1 ms = 1000 us
            % camera properties 'again'
            scr=getselectedsource(app.VidObj);
            scr.ExposureTimeAbs = value*1000; % anges i us 
            disp(['The exposure time was changed to ',num2str(value),' microseconds'])

However, the scr does not "exist" here as it is not a global property. I tried to add it as a global object, bu it didnt like the app.scr everywhere. So I call the scr again with getselectedsource function. Nothing seems to be happening though.

How can i change the exposure time "again" so it will change?

I have tried to change the exposuretime here with code above, but it seems to be nothing happening.

Answer 1

[Hope Q]

I suggest adding some diagnostic statements to assure that you have the desired source object and that is supports the ExposureTimeAbs property. I'm working on a simliar project that sets the FrameRate property.

You can also create an app property for the selected source that you don't have to keep calling getselectedsource().

For example:

app.videoCam = getselectedsource(obj.VidObj);

propertyList = set(obj.videoCame,'FrameRate'') % gives options for FrameRate