QSerial - Can't read Arduino serial data

[LuizSabbagh]

Hello!

This is my first project using Qt and Arduino together. I'm trying to read and write data using a GUI and Arduino Uno, but I don't know what is happening.

I want to click on a pushButton and receive the data that is on Serial. My code is not accessing readSerial and I believe that the problem is on the SIGNAL(readyRead()).

void MainWindow::on_pushButton_clicked()
{
    arduino_is_available = false;
    arduino_port_name = "";
    arduino = new QSerialPort;

    foreach(const QSerialPortInfo &serialPortInfo, QSerialPortInfo::availablePorts()){
        if(serialPortInfo.hasVendorIdentifier() && serialPortInfo.hasProductIdentifier()){
            if(serialPortInfo.vendorIdentifier() == arduino_uno_vendor_id){
                if(serialPortInfo.productIdentifier() == arduino_uno_product_id){
                    arduino_port_name = serialPortInfo.portName();
                    arduino_is_available = true;
                }
            }
        }
    }

    if(arduino_is_available){
        // open and configure the serialport
        arduino->setPortName(arduino_port_name);
        arduino->open(QSerialPort::ReadWrite);
        arduino->setBaudRate(QSerialPort::Baud9600);
        arduino->setDataBits(QSerialPort::Data8);
        arduino->setParity(QSerialPort::NoParity);
        arduino->setStopBits(QSerialPort::OneStop);
        arduino->setFlowControl(QSerialPort::NoFlowControl);
        QObject::connect(arduino, SIGNAL(readyRead()), this, SLOT(readSerial()));

    }else{
        // give error message if not available
        QMessageBox::warning(this, "Port error", "Couldn't find the Arduino!");
    }
}

void MainWindow::readSerial(){
    qDebug() << "Teste 1";
    QByteArray daraSerial = arduino->readAll();
    serialBuffer += QString::fromStdString(daraSerial.toStdString());
    //std::cout << serialBuffer.toStdString();
    qDebug() << "Teste 2";
    qDebug() << serialBuffer;
    qDebug() << daraSerial;
}

My Arduino code is just a loop with Serial.print("a"); and a delay.

I have no idea how to solve this. I read some posts on the forum and didn't find something that solves my problem.

What am I doing wrong?

QObject::connect(arduino, SIGNAL(readyRead()), this, SLOT(readSerial())); is returning true.

Thank you!

[J.Hilk]

@LuizSabbagh
what Qt version are you using ? if it's below 12.6 or 13.2 you'll have to update, as the Serialport module had a bug in some versions.

[LuizSabbagh]

I'm using 5.12.5. I'll try to update.

[LuizSabbagh]

@J-Hilk Fixed! Thank you!

[Jamshid]

@J-Hilk Thanks man, your answer saved my time also,
I had Qt 5.13.1 and serial read was not working, I updated to 5.14.0 and now it works.