QSerialPort open error code 10

kuzulis · 27 Oct 2020, 10:42

You can try the following WinAPI code at first:

    QByteArray systemLocation = "COM5";
    DWORD desiredAccess = GENERIC_READ | GENERIC_WRITE;

    HANDLE handle = ::CreateFile(reinterpret_cast<const wchar_t*>(systemLocation.utf16()),
                              desiredAccess, 0, nullptr, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, nullptr);
    if (handle == INVALID_HANDLE_VALUE) {
        // OOPS
        const DWORD error = ::GetLastError();
        qDebug() << "ERROR:" << error;
    }

ti see what happens.

kuzulis · wrote on 27 Oct 2020, 09:52

I can download the source of QSerialPort and try to debug when I open it.
It could help me to investigate the real problem?

Yes, of course.

addebito · wrote on 27 Oct 2020, 10:42

@kuzulis I get the error 2.... file doesn't exist ??
the error code 2 is really file not exixt ??

Screenshot from Windows device manager:

This is the code.

    DWORD desiredAccess = GENERIC_READ | GENERIC_WRITE;

    HANDLE handle = ::CreateFile(reinterpret_cast<const wchar_t *>("COM5"), desiredAccess, 0, nullptr, OPEN_EXISTING, FILE_FLAG_OVERLAPPED, nullptr);
    if (handle == INVALID_HANDLE_VALUE)
    {
        // OOPS
        const DWORD error = ::GetLastError();
        qDebug() << "ERROR:" << error;
    }

addebito · wrote on 27 Oct 2020, 10:45

@Christian-Ehrlicher said in QSerialPort open error code 10:

Do you have maybe another USB-serial converter for testing?

No, is not a USB serial converter but is a USB connected directly on the device/board.
I can ask my customer to give me back the fisrt board (the one that I starting to work with).
It could be the board or firmware yes.... but why with Hercules I can communicate without problems ??

Christian Ehrlicher · 27 Oct 2020, 11:44

@addebito said in QSerialPort open error code 10:

reinterpret_cast<const wchar_t *>("COM5")

And this is wrong. Either use the solution from @kuzulis or pass a proper utf-16 encoded string: L"COM5"

addebito · 27 Oct 2020, 12:29

@Christian-Ehrlicher you are right but there isn't a call ".utf16()" in QByteArray class so I've replaced with a mistake.

Now the CreateFile with L"COM5" works. I don't get any error.

Christian Ehrlicher · 27 Oct 2020, 13:12

@addebito said in QSerialPort open error code 10:

QByteArray

Because it should be QString :)

Ok, then you have to debug by yourself, don't see what should go wrong within QSerialPort code nor can I test it locally.

addebito · wrote on 27 Oct 2020, 13:12

@Christian-Ehrlicher said in QSerialPort open error code 10:

Ok, then you have to debug by yourself, don't see what should go wrong within QSerialPort code nor can I test it locally.

Yes but is not as easy as I thought.
I've run the maintenance QT software and I've check if the source was installed.

I've created a simple demo project and added this lines inside the .pro

include(C:/Qt/5.14.2/Src/qtserialport/src/serialport/serialport-lib.pri)

I have to add also these lines to resolve some issues

INCLUDEPATH += "C:/Qt/5.14.2/Src/qtbase/include/QtCore/5.14.2/QtCore"
INCLUDEPATH += "C:/Qt/5.14.2/Src/qtbase/include/QtCore/5.14.2"
INCLUDEPATH += "C:/Qt/5.14.2/msvc2017_64/include/QtCore/5.14.2"

But now, when I compile I get this error:

definition of dllimport static data member not allowed

I think there is something wrong in my approach...
How should i do to debug QSerialPort class?
thank you for your time and your patience.

Christian Ehrlicher · 27 Oct 2020, 13:21

I don't understand why you try to compile QSerialPort by yourself. Install the debug symbols and sources, compile your app with debug informations, add a breakpoint on QSP::open() call and step into the call.

addebito · 27 Oct 2020, 13:27

@Christian-Ehrlicher what you means with "Install the debug symbols and sources"?

I'm in debug with a breakpoint but if try to step into by F11...

KroMignon · 27 Oct 2020, 13:31

@addebito said in QSerialPort open error code 10:

what you means with "Install the debug symbols and sources"?

With Maintenance Tool, select "Sources" and "Qt Debug Information Files" for the select Qt Version:

Then build your project in "Debug" and start debugging.

addebito · 27 Oct 2020, 13:37

@KroMignon I've already installed but I don't see anything when I step into...
I see only the debugger on line 118 (qflags.h) and after F11 again the debugger return on my mainwindow.cpp.

J.Hilk · 27 Oct 2020, 14:08

@addebito
did you add the sources inside QtCreator ? In the Debugger section

Christian Ehrlicher · wrote on 27 Oct 2020, 13:45

@addebito said in QSerialPort open error code 10:

I see only the debugger on line 118 (qflags.h) and after F11 again the debugger return on my mainwindow.cpp.

That's correct since first the flags ctor is called, then hit F11 again to step into the function call.

addebito · J J.Hilk 27 Oct 2020, 13:37

@J-Hilk Thank you. Now I can step into.

Now I found the line when the class call "return false"

SetCommState return 87

J.Hilk · 27 Oct 2020, 14:34

Well, if I'm not mistaken, then thats the error code for an invalid parameter 🤷‍♂️

What Windows version do you use ? Is it up to date ? The windows Api changes regularly

addebito · J J.Hilk 27 Oct 2020, 14:22

@J-Hilk

https://docs.microsoft.com/it-it/windows/win32/debug/system-error-codes--0-499-?redirectedfrom=MSDN

Yes, from msdn
87 The parameter is incorrect.

What kind of parameters ??
Ohh Windows...
I'm definitely being roasted.

Windows 10 home
Auto update activated
QT 5.14.2

Any other suggestions?

kuzulis · 27 Oct 2020, 15:37

@addebito said in QSerialPort open error code 10:

Any other suggestions?

Build qtserialport from sources (just download the sources, open in QtCreator and re-build all targets, include examples). And then from the QtCreator run the terminal-example under the debugger, open your serial port and try to debug as usual.. Then, try to comments-out step-by-step the functions like qt_set_{common|baudrate...}, and then re-build qtserialport and try again.. And then you can look wich function brokes the work.

For this, you can temporary rename the qtserialportd.dll in your installed Qt path.. In this case will be used another dll compiled in qtserialport build directory (make sure that this directory is in `run environment' PATH of your project settings in QtCreator).

addebito · wrote on 27 Oct 2020, 15:37

Thank you @kuzulis , I'll try.

I've done another test, same hardware and same computer but with Linux Ubuntu 20.04.1 LTS.
No problem, I can open the "ttyACM0" write and receive data.

Christian Ehrlicher · wrote on 27 Oct 2020, 16:37

Since you can already call CreateFile() simply go further and call GetCommState/SetCommState and set the parameters one by one according to what Qt does and see which one fails. Maybe first try to call SetCommState without modifying the DCB structure at all.