GUI:Usage of start button runs for once and then MATLAB gets strucked

Hello,

I made a GUI in GUI builder and expected to work like this

start button : start streaming the data from comport should stop the streaming data

start button : should stop the data streaming from comport

Exit button : should close the GUI

Problem: 1)when the start button is clicked it is streaming the data and showing on the plot perfectly but when a exit was made and tried to start the data streaming again by clicking the start button it is showing

MATLAB:serial:fopen:opfailed in command window

and the MATLAB gets strucked and needs a manual restart.

2) Also clicking the stop button is not stopping the data streaming.

function varargout = start1(varargin)
gui_Singleton = 1;
gui_State = struct('gui_Name',       mfilename, ...
                   'gui_Singleton',  gui_Singleton, ...
                   'gui_OpeningFcn', @start1_OpeningFcn, ...
                   'gui_OutputFcn',  @start1_OutputFcn, ...
                   'gui_LayoutFcn',  [] , ...
                   'gui_Callback',   []);
if nargin && ischar(varargin{1})
    gui_State.gui_Callback = str2func(varargin{1});
end

if nargout
    [varargout{1:nargout}] = gui_mainfcn(gui_State, varargin{:});
else
    gui_mainfcn(gui_State, varargin{:});
end

function start1_OpeningFcn(hObject, eventdata, handles, varargin)
handles.output = hObject;
guidata(hObject, handles);

function varargout = start1_OutputFcn(hObject, eventdata, handles) 
varargout{1} = handles.output;

start=uicontrol('Style','pushbutton','String', 'start', 'Position',[20 400 50 20],'Callback',@startbutton_Callback);
stop=uicontrol('Style','pushbutton','String', 'stop', 'Position',[20 300 50 20],'Callback',@stopbutton_Callback);
Exit=uicontrol('Style','pushbutton','String', 'Exit', 'Position',[20 100 50 20],'Callback',@pushbutton1_Callback);
writetofile=uicontrol('Style','pushbutton','String', 'writetofile', 'Position',[20 200 50 20],'Callback',@writetofile_Callback);

function pushbutton1_Callback(hObject, eventdata)
handles = guidata(hObject);
 s_quitgui = true;
display('Goodbye');
close(gcf);

function startbutton_Callback(hObject, eventdata)
handles = guidata(hObject);
axes(handles.axes2);
linewidth = 1; 
raw1_gyr = line('Parent',handles.axes2,...
    'XData',[],...
    'YData',[],...
    'Color',[0 0 1],...
    'LineWidth',linewidth);
com_port = 12;
sampleCounter = 1;
dt =  5*(1e-2);
data_file_name = 'pulse_data.txt';
FID = [];
s_writetofile = false;
s_quitgui = false;
s1 = open_com_port(12);
gui_update_freq_divisor = 20;
flushBytesThreshold = 1000;
k = 1;
    while ~s_quitgui            
            nb = s1.BytesAvailable;            
            if nb > flushBytesThreshold
                error('serial data overflow')
            end            
            if(nb)                
                currtime(k) = sampleCounter*dt;                
                [tline,count] = fgetl(s1);
                data_tmp = str2num(char(tline));
                data(k)=(data_tmp);

                  if s_writetofile
                      fprintf(FID,'%f %f \n',currtime,data);
                  end

                  if (~mod(sampleCounter,gui_update_freq_divisor))                   
                      axes(handles.axes2);
                      set(raw1_gyr,'XData',[get(raw1_gyr,'Xdata') currtime]);
                      set(raw1_gyr,'YData',[get(raw1_gyr,'YData') data]);
                      set(handles.axes2,'XLim',[currtime(1)-1 currtime(1)])
                      set(handles.axes2,'YLim',[-1 5000])                    
                      k = 0;
                  end                
                  sampleCounter = sampleCounter + 1;
                  k = k + 1;
              end
          end        

function stopbutton_Callback(hObject, eventdata)
handles = guidata(hObject);

function writetofile_Callback(hObject,eventdata)
s_writetofile = false;
data_file_name = 'pulse_data.txt';
    if s_writetofile
        fclose(FID);
        s_writetofile = false;
        set(writetofile,'String','Write to File',...
            'BackgroundColor', defaultuibgcolor)
    else
        FID = fopen(data_file_name,'w');
        s_writetofile = true;
        set(writetofile,'String','Stop Writing',...
            'BackgroundColor','red')
    end

function textbox1_Callback(hObject, eventdata, handles)

% --- Executes during object creation, after setting all properties.
function textbox1_CreateFcn(hObject, eventdata, handles)
if ispc && isequal(get(hObject,'BackgroundColor'), get(0,'defaultUicontrolBackgroundColor'))
    set(hObject,'BackgroundColor','white');
end

Here open_com_port is a fucntion for the comport settings.

can someone help me out in figuring the solution to these.

Thanks.

[Gova ReDDy]

can someone help me with problem solution.

[VRM]

Hello! I just wanted to know if you finally solved problem 1? 'cause I am having the same problem, and I don't know how to solve it. Thanks in advance!

[Jan]

It was impossible to answer the question.

 2) Also clicking the stop button is not stopping the data streaming.

But the callback of the stop button was:

function stopbutton_Callback(hObject, eventdata)
handles = guidata(hObject);

It is clear, that nothing happens here, because there is no code which tries to let anything happen.

The comport was opened, but not closed anywhere. So, VRM, please open a new thread and ask a specific question. Post your code and explain, what is not working as expected.

[Walter Roberson]

VRM answered "already solved my problem, thanks anyway!"