How to configure serialport callback in app designer?

I want to receive streaming data using serial port. The data stream is dense and I don't want to miss any part of it. So I want to configure the BytesAvailableFcn property of serialport by the command 'configureCallback'. I want to read a line of data every time encountering a ternimator. The same function has been realised by .m file, as follows:

arduinoObj = serialport("COM6",9600)
configureTerminator(arduinoObj,"CR/LF");
flush(arduinoObj);
arduinoObj.UserData = struct("Data","","Count",1)
configureCallback(arduinoObj,"terminator",@ UpdateDisplayText)

function  UpdateDisplayText(src,~)
    data = readline(src);
    src.UserData.Data(src.UserData.Count) = string(data);
    src.UserData.Count = src.UserData.Count + 1;
    if src.UserData.Count > 10
        configureCallback(src, "off");
    end
end

However, when I want to do the same thing in app designer. It doesn't work. I want to click a button to open and configure this serialport object. And the callback function is called "UpdateText".

function Button_OpenCloseSerialValueChanged(app, event)
    value = app.Button_OpenCloseSerial.Value;
    if(value==true)
        try
            app.Button_OpenCloseSerial.Text = "Close";
            app.Serial_Port = serialport(app.DropDown_SerialPort.Value,str2double(app.DropDown_Baudrate.Value));
            configureTerminator(app.Serial_Port,"CR/LF");
            flush(app.Serial_Port);
            app.Serial_Port.UserData = struct("Data","","Count",1);
            configureCallback(app.Serial_Port,"terminator",@UpdateText);
        catch ex
            msgbox(ex.message);
        end
    end
    if(value==false)
        try
            app.Button_OpenCloseSerial.Text="Open";
            app.Serial_Port = [];
        catch ex
            msgbox(ex.message);
        end
    end
end

Then I add a private method as callback function.

methods (Access = private)
    function UpdateText(app,~)
         app.TextArea_Display.Value ="Successful";
    end
end

When receiving a teiminator, there are always errors. and the callback function is never executed.

Could anyone help me to explain what went wrong?

Any help would be great appreciated~

[Jakob Käppler]

Hello, i have the same Problem. Have you found any solutions yet? Best regards.

[wu xianhua]

i have the same problem too, have any solutions yet ?? THS

[chen junjin]

Answer 1

[chen junjin]

[Jesse Lackey]

Shame on you Mathworks for not having anything about how to implement this important capability documented. RIDICULOUS.

Answer 2

[Chirag]

methods (Access = public)
    function readSerialData(app,src,~) % Make Sure to add 'app' as first arguement and 'src' as second arguement
        raw = readline(src);
        data = str2num(raw{1});
        addpoints(app.h,data(1),data(2));
    end
end
    
function StartButtonPushed(app, event)
    app.arduinoObj = serialport(app.comPort,app.baudRate);                
    configureTerminator(app.arduinoObj,"CR/LF","CR/LF");
    % Please configure the Callback as below
    configureCallback(app.arduinoObj,"terminator",@(src, event) readSerialData(app,src,event));
end

[Javier de Hoyos García]

Thank you!!!!

Answer 3

[Sebastian Neumann]

I also struggeling to get the callback function running within app designer in conjunction with the "configureCallback" function.

I have set up an arduino which deivers some serial data within a 5s period.

Can anyone help me with this issues?

It seams to me too that the callback function is never executet, as you stated at the beginning of your question (it works perfect if I run it from a script)

I have searched the entire day for some documentation but I can't find anything ... Apprechiate your help!!

    properties (Access = private)   
        arduinoObj % Serial Arduino Object
    end

    methods (Access = private)
        
        function Init(app)
                     
            app.arduinoObj = serialport("COM4",9600);
            
            configureCallback(app.arduinoObj,"terminator",@app.readSerialData);
            
            disp("Init ok") 
            
        end
        
        
        function readSerialData(app,~,~)
            %data = readline(src);
            %disp(data)
            %Status = data(25:27)
            app.SerialInterfaceTextArea.Value = "I'm in the loop";
            disp("I'm in the loop") 
        end
        
        end 
        
        
    % Callbacks that handle component events
    methods (Access = private)

    % Code that executes after component creation
    function startupFcn(app)
       
        Init(app);
            
            
        end