Matlab App Designer does not respond after running for ~15min

Hello,

I am relatively new to Matlab and I'm trying to use several sensors to measure temperature, pressure etc.

Therefor I use the Arduino Mega2560. In the Arduino IDE I read out the measured values. In Matlab App Designer I use the Serial-API to get the values.

In the app the measured values are displayed in diagrams and can be saved after pressing a button.

After running the code for about 15-20 minutes the program doesn't respond any more, e.g. pressing a button does not cause any action any more. Additional I am not able to close the window at all.

I need to execute those actions, because the measurement has to run for about 20 minutes and than I have to stop the code, so that the values get stored in a file.

Thanks! I hope someone can help me :)

Here is my code: (for only one sensor for easier understanding)

function startupFcn(app)            
            % Arrays for saving values            
            vals1 = [];                         
            saveButton = 0;
            % Initalizing Diagrams
            app.UIAxesTemp.XLim = [0 100];
            app.UIAxesTemp.YLim = [0 70];        
            % variable to check if any values are in the arrays already
            valuesInArray = 0;
            % variable to see if values should be saved already             
            savevalues = 0;
            % variable to see if a file alrady have been saved
            filesaved = 0;  
            % variable to claim which sensor should be read
            neededSensor = 0;
             
            % variables for getting time
            t1 = now;
            t11 = datevec(t1);
            % Initializing Serial-API
            delete(instrfind({'port'},{'COM7'})); 
            s=serial('COM7', 'BaudRate', 9600, 'Terminator','CR'); 
            fopen(s); 
            
            while app.StopProgram.Value == 0
               %Read data
               data = fscanf(s);                                 
               temp = string(data);
               t2 = now;
               t22 = datevec(t2);               
               time = etime(t22,t11);

               if regexp(temp, "[0-5] {1,}[0-9]{1,}.[0-9]{1,}") %format of output of Arduino IDE
                   % sensorNr: the number of the sensor, from which the
                   % value is coming
                   sensorNr = cast(extractBetween(temp, 2, 2), 'double');
                                                             
                   value = cast(regexp(temp, '([0-9]{1,}.[0-9]{1,})', 'match'), 'double');
                   
                   switch neededSensor
                       case 1
                           app.Sensor2TemperaturinCEditField.Value = value;
                           hold(app.UIAxesTemp, 'on');
                           s2 = plot(app.UIAxesTemp,time,wert,'xm');
                           if saveButton == 1
                               vals1 = [vals1; value];
                               valuesInArray = 1;
                           end                                                      

                       % case 2,3,4 etc. (for more sensors)
                           
                           saveButton = app.SpeichernButton.Value;
                   end
                   
                   %needed sensor count up (doesnt matter for this problem)
                   
               else
                   disp("No data found.");                   
               end

               fileName = app.FileNameEditField.Value;

               %Look if there are values in the Arrays, if the saveButton
               %is deactivated again and if the file hasn't been saved yet.               
               if valuesInArray == 1 && saveButton == 0 && fileSaved == 0;                                      
                   finalData = [vals1]; %other arrays for more sensors
                   writematrix(fin, strcat('C:\Users\[...]',fileName,'.xlsx'));
                   fileSaved = 1;                   
               end               

               pause(0.1);

            end        
            close(app.UIFigure);

        end

Answer 1

[Michael Van de Graaff]

You have an fopen but no fclose. that's generally not a great idea in my experience

Is fopen even supposed to be used in this context?

[Anna Lübbers]

Hello, thanks for your answer.

I have now changed the serial function to the serialport function, because the serial function is outdated. I will retry the program tomorrow to see if the problem is still there.

[Anna Lübbers]

I think using serialport solved the problem. So I didn't have to use fopen anymore either.

[Anna Lübbers]

Hello, unfortunately, serialport did not solve the problem. Yesterday I had suspected this because the program ran fine for 30 minutes. Today, however, the program has again stopped responding after about 15-20 minutes. It did output the measured data. But the values could not be saved, a diagram, whose borders should change over time, did not expand anymore and the buttons did not react to a click. Do you have any other ideas why this problem occurs?