How do I create a GUI that runs specific sections of code?

Hello everyone,

I am fairly new to Matlab and I have a problem creating a GUI using App Designer. I have the following piece of code that establishes a connection to my PicoScope 2204A, generates a sine wave, measures this wave in Channel A and then plots it. It works perfectly fine:

%% ESTABLISH CONNECTION AND GENERATE SIGNAL
clear;
clc;
close all;

%% Load Configuration Information

PS2000Config;

%% Device Connection

% Create a device object. 
ps2000DeviceObj = icdevice('picotech_ps2000_generic.mdd');

% Connect device object to hardware.
connect(ps2000DeviceObj);

%% Obtain Signal Generator Group Object
% Signal Generator properties and functions are located in the Instrument
% Driver's Signalgenerator group.

sigGenGroupObj = get(ps2000DeviceObj, 'Signalgenerator');
sigGenGroupObj = sigGenGroupObj(1);

%% Built-in Signal Generator

% Output a sine wave.
%
% Default offset (0mV) and peak to peak voltage (2000mV) values are used. 
% Set the startFrequency to output a waveform with a constant frequency of
% 500Hz.

set(sigGenGroupObj, 'peakToPeakVoltage', 1000);
set(sigGenGroupObj, 'startFrequency', 1000);

% Wave type : ps2000Enuminfo.enPS2000WaveType.PS2000_SINE

[status.sigGenSimple] = invoke(sigGenGroupObj, 'setSigGenBuiltInSimple', 0);


%% MEASURE SIGNAL AND PLOT IT

% Obtain references to device groups to access their respective properties
% and functions.

% Block specific properties and functions are located in the Instrument
% Driver's Block group.

blockGroupObj = get(ps2000DeviceObj, 'Block');
blockGroupObj = blockGroupObj(1);

%% Device Configuration
% Set channels:

% Channel     : 0 (ps2000Enuminfo.enPS2000Channel.PS2000_CHANNEL_A)
% Enabled     : 1 (PicoConstants.TRUE)
% DC          : 1 (DC Coupling)
% Range       : 6 (ps2000Enuminfo.enPS2000Range.PS2000_1V)
[status.setChA] = invoke(ps2000DeviceObj, 'ps2000SetChannel', 0, 1, 1, 6);    

% Channel     : 1 (ps2000Enuminfo.enPS2000Channel.PS2000_CHANNEL_B)
% Enabled     : 1 (PicoConstants.TRUE)
% DC          : 1 (DC Coupling)
% Range       : 7 (ps2000Enuminfo.enPS2000Range.PS2000_2V)
[status.setChB] = invoke(ps2000DeviceObj, 'ps2000SetChannel', 1, 0, 1, 7);  

%% Data Collection
% Capture a block of data on Channels A and B together with times. Data for
% channels is returned in millivolts.
disp('Collecting block of data...');

% Execute device object function(s).
[samplingIntervalUs, maxBlockSamples] = invoke(blockGroupObj, 'setBlockIntervalUs', 20);

[bufferTimes, bufferChA, bufferChB, numDataValues, timeIndisposedMs] = invoke(blockGroupObj, 'getBlockData');

disp('Data collection complete.');

%% Stop the Device
% Additional blocks can be captured prior to stopping the device.

stopStatus = invoke(ps2000DeviceObj, 'ps2000Stop');

%% Process Data
% Process data as required. In this example the data is displayed in a
% figure.

disp('Plotting data...')

% Find the time units used by the driver.
timesUnits = timeunits(get(blockGroupObj, 'timeUnits'));

% Append to string.
timeLabel = strcat('Time (', timesUnits, ')');

% Plot the data.

figure1 = figure('Name','PicoScope 2000 Series Example - Block Mode Capture', ...
    'NumberTitle', 'off');

plot(bufferTimes, bufferChA);
title('Block Data Acquisition');
xlabel(timeLabel);
ylabel('Voltage (mv)');
legend('Channel A');
grid on;


%% STOP SIGNAL GENERATOR AND DISCONNECT DEVICE

% Turn Off Signal Generator
% Turn off the signal generator (set the output to 0mV DC).

set(sigGenGroupObj, 'offsetVoltage', 0);
set(sigGenGroupObj, 'peakToPeakVoltage', 0);

[sigGenOffStatus] = invoke(sigGenGroupObj, 'setSigGenOff');

%% Disconnect
% Disconnect device object from hardware.

disconnect(ps2000DeviceObj);
delete(ps2000DeviceObj);

I now want to creat a GUI that goes through this code "step-by-step" with the possibility to take more than one measurement. I want it to have a "start" button that establishes the connection to the PicoScope and generates the signal, a "measurement" button that measures the signal and plots it and a "stop" button that stops the signal generator and disconnects the PicoScope. When I try to just seperate the code into three callback functions, I encounter the following problem:

The "start" button works perfectly. But when I press the "measurement" button, my app seems to have forgotten which oscilloscope I am talking about.

I think I somehow have to save the configuration data I get when executing

PS2000Config;

in properties, but I can not figure out how to do it the right way. If anyone of you knows the answer to my struggle I would really appreciate your help.

Cheers,

Mattis

[Rik]

A GUI is fundamentally nothing more than a visual tool to gather inputs from a user and run functions.

So what you need to do is using the code you currently have and convert them to functions that run each step. That means you need to store the results from PS2000Config. You should be working with functions anyway, as that will allow you to provide a stable and documented interface. Using scripts is fine during the design phase, but you should end up with a function.

So first you need to convert the code you have to functions, then you can call those functions in callback functions.

For general advice and examples for how to create a GUI, have look at this thread.

[Mattis Roost]

Thank you very much! I will try to implement your advice.

[Carolina Seabra]

Hi Mattis Roost,

Did you manage to figure it out? I'm trying to develop a similar app, with PicoScope 5000a, but also am struggling quite a bit on the organization data flow. I've looked for examples online but it was surprisingly pointless. Would be great to hear from you :)

Best,

Caro