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Matlab GUI: Showing data from COM port in listbox without using any push button

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Matuno
Matuno on 21 Jun 2014
Answered: dpb on 21 Jun 2014
I Want to display, in listbox, the data received in COM port. I can show the incoming data in listbox using push button. The data is showing exactly as long as I use push button, but after removing the push button and only using listbox [putting code in listbox's callback] nothing is showing. How can I use listbox to execute the code and shows what it is getting in COM port?
Code::
function listbox1_Callback(hObject, eventdata, handles)
s = serial ('COM6'); % the communication port
fopen(s); %open the serial port
scanText = fscanf(s);
data = scanText;
set(handles.listbox1,'String',...
[data]);
fclose(s);

Accepted Answer

dpb
dpb on 21 Jun 2014
Because there is no event for the listbox w/o a user intervention -- so the callback function will never be called.
You need to create a serial port event callback -- see documentation under "Events and Callbacks" link under the Serial Port Devices section. It's under Data and File Management chapter.

More Answers (1)

Roberto
Roberto on 21 Jun 2014
The callback function of a listbox is executed when you select an element of the list, what I think you might want is to read from device automatically, to achieve this you can use the 'Create function' that is executed when the object is created:
function listbox1_Create_Fcn(hObject, eventdata, handles)
s = serial ('COM6'); % the communication port
fopen(s); %open the serial port
scanText = fscanf(s);
data = scanText;
set(handles.listbox1,'String',...
[data]);
fclose(s);

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