MATLAB: Serial Port opening problem

closeMATLABopenserialserialport

I'm trying to acquire values from a microcontroller using the serial port. However, I'm facing a strange bug!
when I try to run the program for the first time it works and when I try to run it again it gives me an error saying that cannot open the port! But if I close matlab and open it again and run the program it works for the first time only and then same problem arises!
Can anyone help me please ?
Thanks in advance

Best Answer

Hi
you should check, how many ports are open and closed using instrfind syntax in matlab.
>> instrfind
   Instrument Object Array
   Index:    Type:     Status:   Name:  
   1         serial    closed    Serial-COM4
   2         serial    closed    Serial-COM4
   3         serial    closed    Serial-COM1
   4         serial    closed    Serial-COM1
   5         serial    closed    Serial-COM1
   6         serial    closed    Serial-COM1
   7         serial    open      Serial-COM1
now, easily we can close all ports using fclose. and should delete that object. 
   fclose(instrfind)
   delete(mbed)
correct your as like below.. 
try
    mbed = serial('COM1', ...
                  'BaudRate', 9600, ...
                  'Parity', 'none', ...
                  'DataBits', 8, ...
                  'StopBits', 1);       %change depending on mbed configuration
    .......
catch
    %in case of error or mbed being disconnected
    disp('Failed!');
    fclose(mbed); 
    fclose(instrfind);
    delete(mbed);
end
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