incoming serial data interfering with MATLAB callbacks - user-interface

Question

I have a code that utilizes information taken over serial, compares it to a stored string, and then changes the color values of a panel in a GUI. this is done for 2 different panels. once the strcmp for both panels is 1, a button is enabled to close the GUI. i want to use a simple closereq() function to close it, but that wasn't working. to try something different, I commented out the closereq() and added in a disp('Success'). When pressing the button, Success will appear in the command window, but only after I manually pause the program from the editor panel.
this is my code:
function varargout = WorkingGUI3(varargin)
% WORKINGGUI3 MATLAB code for WorkingGUI3.fig
% WORKINGGUI3, by itself, creates a new WORKINGGUI3 or raises the existing
% singleton*.
%
% H = WORKINGGUI3 returns the handle to a new WORKINGGUI3 or the handle to
% the existing singleton*.
%
% WORKINGGUI3('CALLBACK',hObject,eventData,handles,...) calls the local
% function named CALLBACK in WORKINGGUI3.M with the given input arguments.
%
% WORKINGGUI3('Property','Value',...) creates a new WORKINGGUI3 or raises the
% existing singleton*. Starting from the left, property value pairs are
% applied to the GUI before WorkingGUI3_OpeningFcn gets called. An
% unrecognized property name or invalid value makes property application
% stop. All inputs are passed to WorkingGUI3_OpeningFcn via varargin.
%
% *See GUI Options on GUIDE's Tools menu. Choose "GUI allows only one
% instance to run (singleton)".
%
% See also: GUIDE, GUIDATA, GUIHANDLES
% Edit the above text to modify the response to help WorkingGUI3
% Last Modified by GUIDE v2.5 02-Oct-2019 14:53:57
% Begin initialization code - DO NOT EDIT
gui_Singleton = 1;
gui_State = struct('gui_Name', mfilename, ...
'gui_Singleton', gui_Singleton, ...
'gui_OpeningFcn', #WorkingGUI3_OpeningFcn, ...
'gui_OutputFcn', #WorkingGUI3_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
% End initialization code - DO NOT EDIT
% --- Executes just before WorkingGUI3 is made visible.
function WorkingGUI3_OpeningFcn(hObject, eventdata, handles, varargin)
% This function has no output args, see OutputFcn.
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% varargin command line arguments to WorkingGUI3 (see VARARGIN)
handles.uipanels = [handles.uipanel1, handles.uipanel2];
set(handles.pushbutton5, 'enable', 'off');
% Choose default command line output for WorkingGUI3
handles.output = hObject;
% Update handles structure
guidata(hObject, handles);
% UIWAIT makes WorkingGUI3 wait for user response (see UIRESUME)
% uiwait(handles.figure1);
% --- Outputs from this function are returned to the command line.
function varargout = WorkingGUI3_OutputFcn(hObject, eventdata, handles)
delete(instrfind('Port', 'COM3'));
tag = serial('COM3');
fopen(tag);
BOX = char(zeros(2,14)); % matrix to be populated with incoming serial data
TrueValueData = 'C:\RfidChipTrueValues.xlsx';
[~,~,TrueValMat] = xlsread(TrueValueData);
% Creates matrix filled with the correct values
% indexed by box, which is the first row
% all proceeding rows are the master value
for i=1:inf
for n = 1:2
if i>10
readData = fscanf(tag);
if length(readData)>12
BOX(str2double(readData(8)),1:14)= readData(11:24);
if strcmp(TrueValMat{2,n}, BOX(n,:))
set(handles.uipanels(n), 'BackgroundColor', 'g');
else
set(handles.uipanels(n), 'BackgroundColor', 'r');
end
drawnow
if strcmp(TrueValMat{2,1}, BOX(1,:))...
&& strcmp(TrueValMat{2,2}, BOX(2,:)) == 1
set(handles.pushbutton5, 'enable', 'on');
end
end
end
end
end
% varargout cell array for returning output args (see VARARGOUT);
% hObject handle to figure
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
% Get default command line output from handles structure
varargout{1} = handles.output;
% --- Executes on button press in pushbutton5.
function pushbutton5_Callback(hObject, eventdata, handles)
% hObject handle to pushbutton5 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
%closereq();
disp('It Works')
the final section
% --- Executes on button press in pushbutton5.
function pushbutton5_Callback(hObject, eventdata, handles)
% hObject handle to pushbutton5 (see GCBO)
% eventdata reserved - to be defined in a future version of MATLAB
% handles structure with handles and user data (see GUIDATA)
%closereq();
disp('Success')
holds the callback to the button. I know its it correctly connected to the .fig because pressing the button makes Success appear, but only after manually pausing the program.
any help would be much appreciated.

Answer 1

As #Rotem showed, adding a pause after the first for loop successfully allowed the program to close.