Opening of serial port during GUI formation.

Hello everyone,

I am trying to create a GUI which uses serial port for communication. Here, I the GUI runs but I have to everytime open or pass the command to open the serial port when ever I have to communicate.

Is their a possible way by which I can open port just once inside the classdef method instead of writting it again and again in method (static) and opening it again and again. It consumes time and the GUI becomes slow.

I will kindly request, to please help to suggest ways by which I can open serial port only once and then communicate with it as many times as possible.

I have also attached a sample code specifying my current problem.

Thanking you,

Kind regards

classdef classEl < handle
    properties
        fig
        daq
        UI
        position_limits
        position_read_1
        
    end
    properties (SetObservable, AbortSet) % for listeners
        position
        pre_value
    end
    methods
        function obj = classEl() % constructor

            obj.position_limits = [0, 360];
            
            addlistener(obj,'position','PostSet',@classEl.handlePropEvents);
             
            obj.position = [0 0 0 0]; % initial
            obj.pre_value =[0 0 0 0];

            obj.fig = uifigure( 'Name',class(obj),'Position', [100 100 979 446]);
            
            ...
                
            ...

         end
               
    end

methods (Static)
        function handlePropEvents(src,evnt)
            obj = evnt.AffectedObject;
            switch src.Name
                case {'position','pre_value'}
                       
                    if(obj.pre_value(1) ~= obj.position(1))
                        
                        serial_port =serialport("COM4",9600);
                        ...
                        
                    elseif(obj.pre_value(2) ~= obj.position(2))
                        
                        serial_port =serialport("COM4",9600);
                        ...
    				end
            end
        end
    end

end

                        

Answer 1

[Matlab Pro]

Hi

I have enhanced your class:

Added serial_port to the properties:

    properties
        fig
        daq
        UI
        position_limits
        position_read_1
        serial_port
    end

When initiaiting connection - calling this property:

    obj.serial_port = serialport("COM4",9600);

.. and adding a desturctore method to delete the connection when class is deleted:

      function delete(obj) % Destructor
            if ~isempty(obj.serial_port) && ishandle(obj.serial_port) 
                delete(obj.serial_port)
            end
        end

Thus - when class is instantiated - it holds the "obj.serial_port" for usege (like write(obj.serial_port,data,'uint8')

[Paramjit Yadav]

@Noah Respected Sir,

Thank you so much for the answer. It is working.

Kind regards

[Matlab Pro]

.. always happy to help