clear serial port??

This is a discussion on clear serial port?? within the Windows Programming forums, part of the Platform Specific Boards category; Hi guys: Sometimes when I transmmit the data from one com port to the other. And there are always "something" ...

  1. #1
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    clear serial port??

    Hi guys:

    Sometimes when I transmmit the data from one com port to the other. And there are always "something" left in the com port even after I closed the program. I've to restart the computer then. It is kinda of strange, So is there function or way to clear the serial port after the program closed?

    I would appreciate for any help
    Don't laugh at me,I am just a SuperNewbie.

  2. #2
    Registered User Codeplug's Avatar
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    Check out the code I attached in this thread, SFile.zip.
    Use the object if you like, otherwise, just take a look at the PurgeComm() method.

    gg

  3. #3
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    Hi Codeplug
    When I was runing the program, I got such error:

    Compiling...
    SFile.cpp
    Linking...
    LIBCD.lib(wincrt0.obj) : error LNK2001: unresolved external symbol _WinMain@16
    Debug/SFile.exe : fatal error LNK1120: 1 unresolved externals
    Error executing link.exe.
    Creating browse info file...

    SFile.exe - 2 error(s), 0 warning(s)

    What shall I do? Thanks
    Don't laugh at me,I am just a SuperNewbie.

  4. #4
    Registered User Codeplug's Avatar
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    SFile.zip only contains the SFile class. There is no main() or WinMain() that actually uses it.

    gg

  5. #5
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    Thanks, but BTW: in

    BOOL ReadFile(
    HANDLE hFile, // handle to file
    LPVOID lpBuffer, // data buffer
    DWORD nNumberOfBytesToRead, // number of bytes to read
    LPDWORD lpNumberOfBytesRead, // number of bytes read
    LPOVERLAPPED lpOverlapped // overlapped buffer
    )

    is it always nNumberOfBytesToRead = lpNumberOfBytesRead??

    for example if I set ReadFile() to read 10 bytes at a time from input buffer of COM1, so lpNumberOfBytesRead is 10 bytes too?
    Am I right??

    Thanks
    Don't laugh at me,I am just a SuperNewbie.

  6. #6
    Registered User Codeplug's Avatar
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    *lpNumberOfBytesRead is an output parameter and gets set to 0 first thing by ReadFile().
    When ReadFile() returns, *lpNumberOfBytesRead will be 10 only if it read 10 bytes.

    gg

  7. #7
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    Hey I was jsut wondering where you got this class from? Or did you write it yourself?

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