Definitive serial library

[Marco Trapanese]

Hello,

I apologize if my English is not so good.
I use QT4 to develop applications for Windows and Linux, in both desktop and embedded environments.

I need use a lot of serial connections (often I have 4-5 serial devices connected) so I'm looking for a *reliable* and complete serial library. I don't understand why QT4 doesn't support serial communication natively, I think they are used a lot in embedded applications.

Anyway, I'm playing with the Qextserial but it seems to me a bit buggy and it has many limitations.

Please, may you suggest me a complete serial library that:

* works under Windows and Linux,
* uses signals to tell when data is ready to be read (with buffer thresholds)
* has a working lineread() method
* enumerates available ports under both Windows and Linux

I'm asking too much? What do you embedded programmers use?

Thanks

Marco Trapanese
Italy

[kuzulis]

See this topic:
http://www.qtcentre.org/forum/f-qt-p...lue-21168.html

Try the library.
Add to the library all that you want.





PS: but there is a bug.

Example download: http://www.qtcentre.org/forum/attach...6&d=1242923390

[PaceyIV]

Marco Trapanese asks for signal when there is data available. In your code there isn't this features.

See this topic: http://www.qtcentre.org/forum/f-qt-p...ing-21063.html

In the last post there is my class that use QextSerialPort. It implements 2 thread with the signal "dataReceived": it transports the byte available at the serial port. I also made a basic HyperTerminal to test it (It shows ad transmits data in Hexadecimal).

* has a working lineread() method

I don't implement this method: you can add this!

* enumerates available ports under both Windows and Linux

I don't know how to implement this features. In Linux I think I can scan for ttyS* file in /dev/ and maybe also ttyUSB*. I windows I don't know.


Bye

[PaceyIV]

I add this method to query available ports name, on both Windows and GNU\Linux

#ifdef _TTY_POSIX_
#include <QDir>
#endif
 
 
const int MAX_COM_PORT = 20;
 
// Query available SerialPort name
QStringList MySerialPort::availablePortsName()
{
    QextSerialPort testPort;
    testPort.setBaudRate(BAUD115200);
    testPort.setFlowControl(FLOW_OFF);
    testPort.setParity(PAR_NONE);
    testPort.setDataBits(DATA_8);
    testPort.setStopBits(STOP_1);
 
    QStringList portsName;
    QString testPortName;
 
#ifdef _TTY_WIN_
    for (i=1; i<MAX_COM_PORT; i++)
    {
        testPortName = QString("COM%1").arg(i)
        testPort.setPortName(testPortName);
        if (testPort.open(QIODevice::ReadWrite))
        {
            portsName.append(testPortName);
            testPort.close();
        }
 
    }
#else // _TTY_POSIX_
    QDir dir("/dev");
    QStringList filters;
    filters << "ttyS*" << "ttyUSB*";
    dir.setNameFilters(filters);
    dir.setFilter(QDir::Files | QDir::System);
    QFileInfoList list = dir.entryInfoList();
    for (int i=0; i< list.size(); i++)
    {
        portsName.append(list.at(i).canonicalFilePath ());
    }
#endif
 
    return portsName;
}

#ifdef _TTY_POSIX_
#include <QDir>
#endif


const int MAX_COM_PORT = 20;

// Query available SerialPort name
QStringList MySerialPort::availablePortsName()
{
    QextSerialPort testPort;
    testPort.setBaudRate(BAUD115200);
    testPort.setFlowControl(FLOW_OFF);
    testPort.setParity(PAR_NONE);
    testPort.setDataBits(DATA_8);
    testPort.setStopBits(STOP_1);

    QStringList portsName;
    QString testPortName;

#ifdef _TTY_WIN_
    for (i=1; i<MAX_COM_PORT; i++)
    {
        testPortName = QString("COM%1").arg(i)
        testPort.setPortName(testPortName);
        if (testPort.open(QIODevice::ReadWrite))
        {
            portsName.append(testPortName);
            testPort.close();
        }

    }
#else // _TTY_POSIX_
    QDir dir("/dev");
    QStringList filters;
    filters << "ttyS*" << "ttyUSB*";
    dir.setNameFilters(filters);
    dir.setFilter(QDir::Files | QDir::System);
    QFileInfoList list = dir.entryInfoList();
    for (int i=0; i< list.size(); i++)
    {
        portsName.append(list.at(i).canonicalFilePath ());
    }
#endif

    return portsName;
}

To copy to clipboard, switch view to plain text mode 

[Marco Trapanese]

Thank you very much PaceyIV, I'll play with you class!
It's a pity that QT4 doesn't have a built-in serial class, I can't understand why.

In this way, everybody should reinvent the wheel... And there are many people (like me) who aren't so skilled to implement the library themselves.

Marco

[wysota]

There is a big chance a serial class from Qt Extended will make it into desktop Qt.

http://doc.qtsoftware.com/qtextended...liodevice.html
http://doc.qtsoftware.com/qtextended...erialport.html

[Teuniz]

I use the code at http://www.teuniz.net/RS-232/

It does not use signals but it does work with Linux and windows.