how to connect and run stepper motor using Matlab GUI

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good day everyone,
i was wondering if anyone could help me out here..
i was trying to run my matlab GUI to connect to my driver motor and to my stepper motor but this error always comes out when i press the button connect:
??? Error using ==> serial.fopen at 72 Port: COM1 is not available. Available ports: COM3. Use INSTRFIND to determine if other instrument objects are connected to the requested device.
Error in ==> GUI_xyplotter>connect_m1_Callback at 83 fopen(obj1);
Error in ==> gui_mainfcn at 96 feval(varargin{:});
Error in ==> GUI_xyplotter at 16 gui_mainfcn(gui_State, varargin{:});
Error in ==> @(hObject,eventdata)GUI_xyplotter('connect_m1_Callback',hObject,eventdata,guidata(hObject))
??? Error while evaluating uicontrol Callback
does anybody knows what's wrong with the code and the solution to it?..ur help will be greatly appreciated..thanks a lot

Accepted Answer

Walter Roberson
Walter Roberson on 6 Mar 2011
Like it says, use instrfind to determine whether Matlab thinks COM1 is already in use.
What model of computer and which OS are you using? Historically it was common for COM1 and COM3 not to be simultaneously available as they share the same IRQ. It became common for a time for manufacturers to omit COM1 (especially on laptops) or to use COM1 internally for some other device rather than a user-accessible serial port. Is your serial port definitely labeled as being COM1 or is that just what you are expecting it to be? What does the Windows Device Manager say about the COM ports?
Oh I remember -- it become common for COM1 to be used by a built-in modem, and it was the fad for a time to share a single physical connector, with the device being named COM1 when it was being used as a modem and named COM3 when it was being used as a serial port.

More Answers (1)

fremond khoo
fremond khoo on 6 Mar 2011
thanks for answering using acer aspire 4710 and windows xp..i am sorry but im a newbie in matlab and i just started to learn 1 week ago..what do u mean by use instrfind??..
thanks again for ur help^^
vishal Verma
vishal Verma on 2 Apr 2014
Could you plz tell me how you ran your motor using MATLAB GUI? Is there a sample code I can look at? Thanks!

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