Code covered by the BSD License

# MATLAB Support Package for Velleman K8055/VM110 Experiment Board

### MathWorks Classroom Resources Team (view profile)

MATLAB library for communicating with a Velleman K8055/VM110 USB Experiment Interface Board

autodemo3
% AUTODEMO3     -     EasyGUI example using automatic layout and callbacks
%
%   GUI for plotting a lissajous curve
%   (http://en.wikipedia.org/wiki/Lissajous_curve)
%      sin(f1) vs. sin(f2 + theta)
%
%   This example builds on AUTODEMO and AUTODEMO2. It demonstrates
%   how to process all the user input using *several* callback
%   functions. This is more efficient since various signals are
%   recomputed only when necessary.

%   Copyright 2009 The MathWorks, Inc.

function autodemo3

% gui elements
myGui = gui.autogui;
myGui.Name = 'Lissajous figure demo';

freq1 = gui.slider('Frequency 1 (Hz)', [1 40]);
freq2 = gui.slider('Frequency 2 (Hz)', [1 40]);
phaseDiff = gui.numericmenu('Phase difference (degrees)', 0:30:180);
plotType = gui.textmenu('Lissajous plot type', {'2d-phase', '2d-comet'});

% sampling parameters and "global" parameters
Fs = 500;
t = 0:(1/Fs):1;
sig1 = zeros(1,numel(t));
sig2 = zeros(1,numel(t));

ax1 = subplot(10,10, 1:20);
ax2 = subplot(10,10, 31:100);

% callbacks, invoked whenever the Value property changes
freq1.ValueChangedFcn = @recalcSig1;
freq2.ValueChangedFcn = @recalcSig2;
phaseDiff.ValueChangedFcn = @recalcSig2;
plotType.ValueChangedFcn = @redrawPlots;

% set default values. This invokes the callbacks
% and forces calculation of sig1 and sig2.
freq1.Value = 20;
freq2.Value = 25;

function recalcSig1(hWidget) %#ok<INUSD>
% hWidget is the widget with the just-received input
% we don't need this information in this demo
sig1 = sin(2*pi*t*freq1.Value);
redrawPlots(hWidget);
end

function recalcSig2(hWidget) %#ok<INUSD>
redrawPlots(hWidget);
end

function redrawPlots(hWidget) %#ok<INUSD>
axes(ax1);
plot(t,sig1,'b',t,sig2,'r');

axes(ax2);
cla;
xlabel('sin(2 \pi f_1 t)');
ylabel('sin(2 \pi f_2 t + \theta');
axis equal; axis square;
axis([-1.2 1.2 -1.2 1.2]);

switch plotType.Value
case '2d-phase'
plot(sig1,sig2);
case '2d-comet'
comet(sig1,sig2);
end
end

end