Why I am not receiving serial data from arduino? I am using app designer

Hi, I am trying to use this GUI with serial data from arduino, but when I run it nothing happens.

classdef dinvu < matlab.apps.AppBase

    % Properties that correspond to app components
    properties (Access = public)
        FlightInstrumentsFlightDataPlaybackUIFigure  matlab.ui.Figure
        PiperPA24ComancheFlightDataDisplayLabel  matlab.ui.control.Label
        Time000secSlider       matlab.ui.control.Slider
        Time000secSliderLabel  matlab.ui.control.Label
        ClimbIndicator         Aero.ui.control.ClimbIndicator
        HeadingIndicator       Aero.ui.control.HeadingIndicator
        TurnCoordinator        Aero.ui.control.TurnCoordinator
        Altimeter              Aero.ui.control.Altimeter
        ArtificialHorizon      Aero.ui.control.ArtificialHorizon
        AirspeedIndicator      Aero.ui.control.AirspeedIndicator
        Image                  matlab.ui.control.Image
    end

    
    properties (Access = public) 
         a % Saved flight data [time X Y Z phi theta psi]
        animObj % Aero.Animation object
    end
    

    % Callbacks that handle component events
    methods (Access = private)

        % Code that executes after component creation
        function startupFcn(app)
         
           close all;
           clc;
           delete(instrfindall);
           NumMues=10;
           y=zeros(1,NumMues);

           delete(instrfind({"Port"},{"COM4"}));
           micro=serial("COM4");
           micro.BaudRate=9600;
           warning("off","MATLAB:serial:fscanf:unsuccesfulRead");

           fopen(micro);

            % Load saved flight status data
            savedData = fscanf(micro,"%s");
            a = strsplit(savedData, ',');
            yaw = str2double(a(7));
            yaw(yaw<0) = yaw(yaw<0)+2*pi; % unwrap yaw angles
            
            
            % Create animation object to visualize aircraft flight dynamics corresponding with saved data over time 
            app.animObj = Aero.Animation;
            app.animObj.createBody('pa24-250_orange.ac','Ac3d'); % Piper PA-24 Comanche geometry
            app.animObj.Bodies{1}.TimeseriesSourceType = 'Array6DoF'; % [time X Y Z phi theta psi]
            app.animObj.Bodies{1}.TimeSeriesSource = str2double(a(1));
            app.animObj.Camera.PositionFcn = @staticCameraPosition;
            app.animObj.Figure.Position = [app.FlightInstrumentsFlightDataPlaybackUIFigure.Position(1)+625 app.FlightInstrumentsFlightDataPlaybackUIFigure.Position(2) app.FlightInstrumentsFlightDataPlaybackUIFigure.Position(3) app.FlightInstrumentsFlightDataPlaybackUIFigure.Position(4)];
            %app.animObj.updateBodies(app.a(1,1)); % Initialize animation window at t=0
            %app.animObj.updateCamera(app.a(1,1));
            app.animObj.show();

            


        end

        % Value changing function: Time000secSlider
        function Time000secSliderValueChanging(app, event)
            

           delete(instrfindall);
           NumMues=200;
           y=zeros(1,NumMues);

           delete(instrfind({"Port"},{"COM4"}));
           micro=serial("COM4");
           micro.BaudRate=9600;
           warning("off","MATLAB:serial:fscanf:unsuccesfulRead");

           fopen(micro);
            contador=1;

          while contador <=NumMues

            savedData = fscanf(micro,"%s");

            % Display current time in slider component
            t = event.Value;
            app.Time000secSliderLabel.Text = sprintf('Time: %.1f sec', t);           

            % Find corresponding time data entry
            k = find(strsplit(savedData, ',')<=t);
            k = k(end);

                nData{k,1} = str2double(t(1));
                nData{k,2} = str2double(t(2));
                nData{k,3} = str2double(t(3));
                nData{k,4} = str2double(t(4));
                nData{k,5} = str2double(t(5));
                nData{k,6} = str2double(t(6));
                nData{k,2:4}=str2double(t(2:4));
                nData{k-1,2:4}=str2double(t(2:4));
                nData{k,5:7}=str2double(t(5:7));
                nData{k-1,5:7}=str2double(t(5:7));
            
            app.Altimeter.Altitude = convlength(-nData{k,4}, 'm', 'ft');
            app.HeadingIndicator.Heading = convang(nData{k,7},'rad','deg');
            app.ArtificialHorizon.Roll = convang(nData{k,5},'rad','deg');
            app.ArtificialHorizon.Pitch = convang(nData{k,6},'rad','deg');
            
            if k>1
                % Estimate velocity and angular rates
                Vel = (nData{k,2:4}-nData{k-1,2:4})/(nData{k,1}-nData{k-1,1});
                rates = (nData{k,5:7}-nData{k-1,5:7})/(nData{k,1}-nData{k-1,1});
                
                app.AirspeedIndicator.Airspeed = convvel(sqrt(sum(Vel.^2)),'m/s','kts');
                app.ClimbIndicator.ClimbRate = convvel(-Vel(3),'m/s','ft/min');

                % Estimate turn rate and slip behavior 
                app.TurnCoordinator.Turn = convangvel(rates(1)*sind(30) + rates(3)*cosd(30),'rad/s','deg/s');
                app.TurnCoordinator.Slip = 1/(2*pi)*convang(atan(rates(3)*sqrt(sum(Vel.^2))/9.81)-nData{k,5},'rad','deg');
            else
                % time = 0
                app.ClimbIndicator.ClimbRate = 0;
                app.AirspeedIndicator.Airspeed = 0;
                app.TurnCoordinator.Slip = 0;
                app.TurnCoordinator.Turn = 0;
            end

           end
           delete(micro)
            
            %% Update animation window display
            app.animObj.updateBodies(app.a(k,1));
            app.animObj.updateCamera(app.a(k,1));
            
        end

        % Close request function: 
        % FlightInstrumentsFlightDataPlaybackUIFigure
        function FlightInstrumentsFlightDataPlaybackUIFigureCloseRequest(app, event)
            % Close animation figure with app
            delete(app.animObj);
            delete(app); 
           
        end
    end

    % Component initialization
    methods (Access = private)

        % Create UIFigure and components
        function createComponents(app)

            % Create FlightInstrumentsFlightDataPlaybackUIFigure and hide until all components are created
            app.FlightInstrumentsFlightDataPlaybackUIFigure = uifigure('Visible', 'off');
            app.FlightInstrumentsFlightDataPlaybackUIFigure.AutoResizeChildren = 'off';
            app.FlightInstrumentsFlightDataPlaybackUIFigure.Color = [0.2706 0.2706 0.2784];
            app.FlightInstrumentsFlightDataPlaybackUIFigure.Position = [100 100 620 550];
            app.FlightInstrumentsFlightDataPlaybackUIFigure.Name = 'Flight Instruments - Flight Data Playback';
            app.FlightInstrumentsFlightDataPlaybackUIFigure.Resize = 'off';
            app.FlightInstrumentsFlightDataPlaybackUIFigure.CloseRequestFcn = createCallbackFcn(app, @FlightInstrumentsFlightDataPlaybackUIFigureCloseRequest, true);

            % Create Image
            app.Image = uiimage(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.Image.Position = [8 -2 606 577];
            app.Image.ImageSource = 'appdesignerInstrumentPanel.png';

            % Create AirspeedIndicator
            app.AirspeedIndicator = uiaeroairspeed(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.AirspeedIndicator.Limits = [25 250];
            app.AirspeedIndicator.ScaleColorLimits = [0 60;50 200;200 225;225 250];
            app.AirspeedIndicator.Position = [22 317 185 185];

            % Create ArtificialHorizon
            app.ArtificialHorizon = uiaerohorizon(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.ArtificialHorizon.Position = [219 317 185 185];

            % Create Altimeter
            app.Altimeter = uiaeroaltimeter(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.Altimeter.Position = [416 317 185 185];

            % Create TurnCoordinator
            app.TurnCoordinator = uiaeroturn(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.TurnCoordinator.Position = [22 70 185 185];

            % Create HeadingIndicator
            app.HeadingIndicator = uiaeroheading(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.HeadingIndicator.Position = [219 70 185 185];

            % Create ClimbIndicator
            app.ClimbIndicator = uiaeroclimb(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.ClimbIndicator.MaximumRate = 8000;
            app.ClimbIndicator.Position = [416 70 185 185];

            % Create Time000secSliderLabel
            app.Time000secSliderLabel = uilabel(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.Time000secSliderLabel.HorizontalAlignment = 'right';
            app.Time000secSliderLabel.FontSize = 11.5;
            app.Time000secSliderLabel.FontColor = [1 1 1];
            app.Time000secSliderLabel.Position = [267 3 80 22];
            app.Time000secSliderLabel.Text = 'Time: 00.0 sec';

            % Create Time000secSlider
            app.Time000secSlider = uislider(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.Time000secSlider.Limits = [0 49.833333333333];
            app.Time000secSlider.MajorTicks = [0 2 4 6 8 10 12 14 16 18 20 22 24 26 28 30 32 34 36 38 40 42 44 46 48 49.833333333333];
            app.Time000secSlider.MajorTickLabels = {'0', '2', '4', '6', '8', '10', '12', '14', '16', '18', '20', '22', '24', '26', '28', '30', '32', '34', '36', '38', '40', '42', '44', '46', '48', '50'};
            app.Time000secSlider.ValueChangingFcn = createCallbackFcn(app, @Time000secSliderValueChanging, true);
            app.Time000secSlider.MinorTicks = [];
            app.Time000secSlider.FontSize = 11.5;
            app.Time000secSlider.FontColor = [1 1 1];
            app.Time000secSlider.Position = [50 55 520 3];

            % Create PiperPA24ComancheFlightDataDisplayLabel
            app.PiperPA24ComancheFlightDataDisplayLabel = uilabel(app.FlightInstrumentsFlightDataPlaybackUIFigure);
            app.PiperPA24ComancheFlightDataDisplayLabel.BackgroundColor = [0.8 0.8 0.8];
            app.PiperPA24ComancheFlightDataDisplayLabel.HorizontalAlignment = 'center';
            app.PiperPA24ComancheFlightDataDisplayLabel.FontName = 'Courier New';
            app.PiperPA24ComancheFlightDataDisplayLabel.FontSize = 14;
            app.PiperPA24ComancheFlightDataDisplayLabel.FontWeight = 'bold';
            app.PiperPA24ComancheFlightDataDisplayLabel.Position = [141 515 347 22];
            app.PiperPA24ComancheFlightDataDisplayLabel.Text = 'Piper PA-24 Comanche Flight Data Display';

            % Show the figure after all components are created
            app.FlightInstrumentsFlightDataPlaybackUIFigure.Visible = 'on';
        end
    end

    % App creation and deletion
    methods (Access = public)

        % Construct app
        function app = dinvu

            % Create UIFigure and components
            createComponents(app)

            % Register the app with App Designer
            registerApp(app, app.FlightInstrumentsFlightDataPlaybackUIFigure)

            % Execute the startup function
            runStartupFcn(app, @startupFcn)

            if nargout == 0
                clear app
            end
        end

        % Code that executes before app deletion
        function delete(app)

            % Delete UIFigure when app is deleted
            delete(app.FlightInstrumentsFlightDataPlaybackUIFigure)
        end
    end
end

Answer 1

[Nivedita]

Hello María,

I understand you are facing issues with receiving serial data from arduino in you rapp created using MATLAB app designer. I figures some of these issues could be responsible for such behaviour, you could try to modify your code according to these suggestions:

1. The use of "close all" and "clc" in the "startupFcn" method is generally not recommended because it can close all figures and clear the command window which might not be the desired behaviour.
2. You are deleting the serial object in the "startupFcn" and "Time000secSliderValueChanging" functions, which could lead to issues if the serial port does not open properly or if there is an error in communication.
3. You are using "fscanf" to read data from the serial port, but you are not checking if the data is read correctly. This could lead to errors if the data is not received in the expected format.

This code snippet could help you with the modifications:

function startupFcn(app)
    % Initialize serial communication
    if ~isempty(instrfind)
        fclose(instrfind);
        delete(instrfind);
    end
    app.micro = serial("COM4", 'BaudRate', 9600);
    fopen(app.micro);
    % Assuming the rest part of the code is correct`
end

% Value changing function: Time000secSlider
function Time000secSliderValueChanging(app, event)
    % Read data from serial port
    savedData = fscanf(app.micro, "%s");
    if isempty(savedData)
        return; % No data read, exit the function
    end
    a = strsplit(savedData, ',');
    if length(a) < 7
        return; % Not enough data, exit the function
    end
    % Convert the string data to numbers
    numericData = str2double(a);
    % Update the flight instruments using numericData
    % ...
end

Do remember to properly handle the creation and deletion of the serial object to avoid issues with the COM port being left open or in an undefined state. Additionally, ensure that the data received from the serial port is in the correct format and that you handle any possible communication errors.

I hope this helps!

Regards,

Nivedita.