Serial port Communication with pc through serial Adapter

[J.Hilk]

@sankarapandiyan
ok, lets simplify your code, I assume receive and aknowmntare QTextEdits or QTextBrowser, since they have a toPlainTextfunction

void MainWindow::checkAndSendData()
{
    if(!m_lines.isEmpty()){
        QByteArray baToSend = m_lines.takeFirst().toUtf8();
        serial->write(baToSend);
        ui->aknowmnt->append("Sent Message --> "+ QString(baToSend));
    } else {
        ui->aknowmnt->append("All are send ");
    }
}

void MainWindow::serialReceived()

{
    QString glen = serial->readAll();
    if (glen.length()>0){
         ui->receive->append( "Received -->" + QString(glen));
    }
   QMetaObject::invokeMethod(this, &MainWindow::checkAndSendData, Qt::QueuedConnection);

}

[sankarapandiyan]

@J-Hilk

Yes i have tried this method , the correct data is not shown in the receiver side ..

void MainWindow::on_pushButton_clicked()
{
    serial = new QSerialPort (this) ;
    serial->setPortName(ui->comboBox->currentText());
    serial->setBaudRate (QSerialPort::Baud115200);
    serial->setDataBits(QSerialPort::Data8);
    serial->setParity (QSerialPort::NoParity);
    serial->setStopBits (QSerialPort::OneStop);
    serial->setFlowControl(QSerialPort::NoFlowControl);
    serial->open(QIODevice::ReadWrite);
//    connect(serial,SIGNAL(readyRead()),this, SLOT (serialReceived()));
    connect(serial, &QSerialPort::readyRead,this, &MainWindow::serialReceived);

   ui->progressBar->setValue(100);
//    ui->receive->clear();
}

void MainWindow::checkAndSendData()
{
    if(!m_lines.isEmpty()){
        QByteArray baToSend = m_lines.takeFirst().toUtf8();
        serial->write(baToSend);
        ui->aknowmnt->append("Sent Message --> "+ QString(baToSend));
    } else {
        ui->aknowmnt->append("All are send ");
    }
}

void MainWindow::on_send_clicked()
{
     line   = ui->sender->toPlainText();
    QString txt1 = ui->receive->toPlainText();
    /*QString*/ txt3 = ui->aknowmnt->toPlainText();

     if(m_lines.isEmpty()){
    QFile inputFile(QString("/home/adx-soft1/Shankar/serial/myfile1.txt"));
    inputFile.open(QIODevice::ReadOnly);
    if (!inputFile.isOpen())
        return;

    QTextStream stream(&inputFile);
    while (!stream.atEnd()){
            line = stream.readLine();
            m_lines.append(line+QString("\r\n"));
    }

     }
     checkAndSendData();

}

void MainWindow::serialReceived()

{
    QString glen = serial->readAll();
    if (glen.length()>0){
         ui->receive->append( "Received -->" + QString(glen));
    }
   QMetaObject::invokeMethod(this, &MainWindow::checkAndSendData, Qt::QueuedConnection);
}

[sankarapandiyan]

@J-Hilk said in Serial port Communication with pc through serial Adapter:

ok, lets simplify your code, I assume receive and aknowmntare QTextEdits or QTextBrowser, since they have a toPlainTextfunction

Yes Its a QTextEdits

[J.Hilk]

@sankarapandiyan
you're obviously receiving non ascii bytes

void MainWindow::serialReceived()

{
    QByteArray glen = serial->readAll();
    if (glen.length()>0){
         ui->receive->append( QString("Received --> %1").arg(QString(glen.toHex(' ')));
    }
   QMetaObject::invokeMethod(this, &MainWindow::checkAndSendData, Qt::QueuedConnection);

}

[sankarapandiyan]

@J-Hilk said in Serial port Communication with pc through serial Adapter:

void MainWindow::serialReceived()

{
QByteArray glen = serial->readAll();
if (glen.length()>0){
ui->receive->append( QString("Received --> %1").arg(QString(glen.toHex(' ')));
}
QMetaObject::invokeMethod(this, &MainWindow::checkAndSendData, Qt::QueuedConnection);

}

this out put is what i receive from another pc

And the next below image is shown as a data send as some thing different

Even Now also i did not get the exact output sir what should i do i am stuck here .. @J-Hilk

[KroMignon]

@sankarapandiyan Maybe it is a silly question, but are you sure the serial settings your are using, are correct?

• 115200 bauds?
• 8 bits?

Are you using a crossed/null modem serial cable? ==> cf https://en.wikipedia.org/wiki/Null_modem.

[sankarapandiyan]

@KroMignon I am Using hl-340 usb-serial adapter . so here , what i want to give as a baud rate.

void MainWindow::on_pushButton_clicked()
{
    serial = new QSerialPort (this) ;
    serial->setPortName(ui->comboBox->currentText());
    serial->setBaudRate (QSerialPort::Baud115200);
    serial->setDataBits(QSerialPort::Data8);
    serial->setParity (QSerialPort::NoParity);
    serial->setStopBits (QSerialPort::OneStop);
    serial->setFlowControl(QSerialPort::NoFlowControl);
    serial->open(QIODevice::ReadWrite);
    connect(serial,SIGNAL(readyRead()),this, SLOT (serialReceived()));
    ui->progressBar->setValue(100);
//    ui->receive->clear();
}

[KroMignon]

@sankarapandiyan said in Serial port Communication with pc through serial Adapter:

I am Using hl-340 usb-serial adapter

Okay, that's for having a RS232 port on you PC, but to connect two PC you need a "null modem" cable (to cross Tx and Rx signal between the 2 serial ports).
Have you something like this?

[sankarapandiyan]

@KroMignon Yes you are right ..
this is my null modem i am using

I dontknow i am ryt or wrong and i am new to this topic .. the above image shows my serial adapter with null modem

[KroMignon]

@sankarapandiyan Okay, so the hardware side seems to be right. Can you give your software environnement:

• Operation system you are using (Linux ? Windows? MacOS?)
• Qt Kit Version you are using (not Qt Creator version!)

[sankarapandiyan]

@KroMignon

Operation system you are using (Linux ? Windows? MacOS?)
Linux_Ubuntu18.04.3
Qt Kit Version you are using (not Qt Creator version!)
**I dont know how to find the Qt kit version but any way little bit i have find out i think ..the below image shows the version of kit ** @KroMignon

[KroMignon]

@sankarapandiyan said in Serial port Communication with pc through serial Adapter:

Linux_Ubuntu18.04.3

Have you tried your serial interface with another tool like cutecom.
On Ubuntu/Debian, you can install it with apt-get install cutecom

[sankarapandiyan]

@KroMignon

YEs I have done its working in the application ... @KroMignon