Operating on while loop outside the loop matlab - matlab

Question

i've got problems with my Nucleo.
Im using Matlab to cooperate with my Nucleo board.
I want to build programmatically GUI with buttons, figures etc. I'm going to put whole functionality in while loop. And now there's my question.
Is there any posibility to put whole code in while loop and operate it through callback functions outside the loop?
For example: Im my loop i want to send some data to Nucleo on btn1 press, and i want to stop it on btn2 press(Of course if statements for btns). Is there possibility to do it by changing the button values or something like that(Flags etc.)?
I don't want use global variables.

Answer 1

Yes it's possible...
It's not the best programming pattern, but it's very convenient approach for small software projects.
I recommend you to use MATLAB App Designer.
App Designer uses OOP programming model, that makes it simpler to pass data (without using global variables, and without complicated solutions that are used with GUIDE).
Here is a sample instructions:
Start App Designer - execute appdesigner from command line.
Add two buttons, and two labels (add anything else later).
Add callbacks: for start button set flag to true and in stop button to false.
The syntax is app.is_sending = true (when is_sending is a property of app).
Change from Design View to Code View.
Add private properties: loop_counter = 0;, sending_counter = 0;, is_sending = false;.
Add callback - select startupFcn callback function.
Put your while loop in the startupFcn callback.
Use while isvalid(app)
Place your while loop functionality inside the while loop.
Place your sending code with if (app.is_sending)...
Very important: at the end of the loop call pause function.
You must execute pause or drawnow to allow callbacks to be responsive.
When using App Designer, some code is generated automatically, and cannot be modified in Code View.
The following code sample includes both generated code, and customized code:
classdef app1 < matlab.apps.AppBase
% Properties that correspond to app components
properties (Access = public)
UIFigure matlab.ui.Figure
StartSendingButton matlab.ui.control.Button
StopSendingButton matlab.ui.control.Button
Sending0Label matlab.ui.control.Label
LoopCounter0Label matlab.ui.control.Label
end
properties (Access = private)
loop_counter = 0 % Count while loop iteration
sending_counter = 0; %Count only while "sending data"
is_sending = false; %Flag: if value is true, assume "sending"
end
% Callbacks that handle component events
methods (Access = private)
% Code that executes after component creation
function startupFcn(app)
%While loop: loop until app is not valid.
while isvalid(app)
%Place your while loop functionality here:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
app.loop_counter = app.loop_counter + 1; %Increase loop counter
app.LoopCounter0Label.Text = ['Loop Counter: ', num2str(app.loop_counter)]; %Update loop coouner text lable.
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%Place your sending code here:
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
if (app.is_sending)
app.sending_counter = app.sending_counter + 1; %Increase sending counter
app.Sending0Label.Text = ['Sending: ', num2str(app.sending_counter)]; %Update sending coouner text lable.
end
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
%%%% Important %%%%
%Short pause must be used in order to allow buttons callbacks to be responsive (you can also call drawnow).
pause(0.01)
%%%% Important %%%%
end
end
% Button pushed function: StartSendingButton
function StartSendingButtonPushed(app, event)
app.is_sending = true; %Set flag to true when button is pressed.
end
% Button pushed function: StopSendingButton
function StopSendingButtonPushed(app, event)
app.is_sending = false; %Set flag to false when button is pressed.
end
end
% Component initialization
methods (Access = private)
% Create UIFigure and components
function createComponents(app)
% Create UIFigure and hide until all components are created
app.UIFigure = uifigure('Visible', 'off');
app.UIFigure.Position = [100 100 440 304];
app.UIFigure.Name = 'UI Figure';
% Create StartSendingButton
app.StartSendingButton = uibutton(app.UIFigure, 'push');
app.StartSendingButton.ButtonPushedFcn = createCallbackFcn(app, #StartSendingButtonPushed, true);
app.StartSendingButton.BackgroundColor = [0.3922 0.8314 0.0745];
app.StartSendingButton.FontSize = 16;
app.StartSendingButton.Position = [33 197 130 49];
app.StartSendingButton.Text = 'Start Sending';
% Create StopSendingButton
app.StopSendingButton = uibutton(app.UIFigure, 'push');
app.StopSendingButton.ButtonPushedFcn = createCallbackFcn(app, #StopSendingButtonPushed, true);
app.StopSendingButton.BackgroundColor = [0.851 0.3255 0.098];
app.StopSendingButton.FontSize = 16;
app.StopSendingButton.Position = [33 129 130 49];
app.StopSendingButton.Text = 'Stop Sending';
% Create Sending0Label
app.Sending0Label = uilabel(app.UIFigure);
app.Sending0Label.FontSize = 16;
app.Sending0Label.Position = [229 203 151 37];
app.Sending0Label.Text = 'Sending: 0';
% Create LoopCounter0Label
app.LoopCounter0Label = uilabel(app.UIFigure);
app.LoopCounter0Label.FontSize = 16;
app.LoopCounter0Label.Position = [37 44 193 37];
app.LoopCounter0Label.Text = 'Loop Counter: 0';
% Show the figure after all components are created
app.UIFigure.Visible = 'on';
end
end
% App creation and deletion
methods (Access = public)
% Construct app
function app = app1
% Create UIFigure and components
createComponents(app)
% Register the app with App Designer
registerApp(app, app.UIFigure)
% 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.UIFigure)
end
end
end
You can copy and paste the entire code into an m file, to see how it works.
The code sample is not sending any data (and not related to Nucleo board), it's just advancing counters.
Here is how the sample application interface looks like: