How to send and receive in the sametime

victor wang

Hi, I'm using QT5.5 on my computer.
I wanna write a program that will do send and receive in the same place and time.
This is my code.

QSerialPort comport;
    QString comportstring="/dev/ttyXRUSB0";
    comport.setPortName(comportstring);
    comport.setBaudRate(115200);

    if (!comport.open(QIODevice::WriteOnly)) {
        qDebug()<<comport.errorString();
    }
    QByteArray writeData="HELLO WORLD!";
    qDebug("here am i ")
    if (writeData.isEmpty()) {
 qDebug()<<"Either no data was currently available on the standard input ff
or reading, or an error occurred for port";
    }

    qint64 bytesWritten = comport.write(writeData);

    if (bytesWritten == -1)
    {
        qDebug()<<"Failed to write the data to port";
    }
    else if (bytesWritten != writeData.size())
    {
        qDebug()<<"Failed to write all the data to port";
    }
    else if (!comport.waitForBytesWritten(5000))
    {
        qDebug()<<"Operation timed out or an error occurred for port";
    }

    qDebug()<<"Data successfully sent to port";
    QByteArray readData=comport.readAll();
    while(comport.waitForReadyRead(5000))
        readData.append(comport.readAll());
 if(comport.error()==QSerialPort::ReadError)
    {
        qDebug("Failed to read");
    }
    else if(comport.error()==QSerialPort::TimeoutError)
    {
        qDebug("Time is out");
    }
    else if(readData.isEmpty())
    {
        qDebug("no data is currently available");
    }
    qDebug()<<"read successfully :"<<readData.constData();

I wanna receive the words that i just write in.
But It cannot do what i want it to do.
It will show read timeout.
What can i do?
Did i miss something here?
Please help!

kuzulis

Did i miss something here?
I wanna write a program that will do send and receive in the same place and time.
comport.open(QIODevice::WriteOnly)