This uses two classes provided by the QSerialPort module: the QSerialPort class and the QSerialPortInfo class, the QSerialPort class provides operations on the serial port, and the QSerialPortInfo class provides access to the serial port information.The following is the main code, which contains a simple use of the serial class.

First, be sure to add in the.pro file: QT += serialport

The serial port is initialized as follows:

1. /****************************Serial port initialization*****************************************/  
2. void MainWindow::initPort()  
3. {  
4.     //Read Serial Port Information  
5.     foreach (const QSerialPortInfo &info, QSerialPortInfo::availablePorts())  
6.     {  
7.         qDebug()<<"Name:"<<info.portName();  
8.         qDebug()<<"Description:"<<info.description();  
9.         qDebug()<<"Manufacturer:"<<info.manufacturer();  
10.   
11.         //This is equivalent to adding cmb after recognizing serial number automatically, if you want to select manually you can add it in the following list  
12.         QSerialPort serial;  
13.         serial.setPort(info);  
14.         if(serial.open(QIODevice::ReadWrite))  
15.         {  
16.             //Add serial number to cmb  
17.             ui->cmbPortName->addItem(info.portName());  
18.             //Close the serial port and wait for it to be opened manually (open the serial button)  
19.             serial.close();  
20.         }  
21.     }  
22.   
23.     QStringList baudList;//baud rate  
24.     QStringList parityList;//Check bits  
25.     QStringList dataBitsList;//Data bits  
26.     QStringList stopBitsList;//Stop Bit  
27.   
28.     baudList<<"50"<<"75"<<"100"<<"134"<<"150"<<"200"<<"300"  
29.            <<"600"<<"1200"<<"1800"<<"2400"<<"4800"<<"9600"  
30.           <<"14400"<<"19200"<<"38400"<<"56000"<<"57600"  
31.          <<"76800"<<"115200"<<"128000"<<"256000";  
32.   
33.     ui->cmbBaudRate->addItems(baudList);  
34.     ui->cmbBaudRate->setCurrentIndex(12);  
35.   
36.     parityList<<"nothing"<<"odd"<<"even";  
37.     parityList<<"sign";  
38.     parityList<<"Spaces";  
39.   
40.     ui->cmbParity->addItems(parityList);  
41.     ui->cmbParity->setCurrentIndex(0);  
42.   
43.     dataBitsList<<"5"<<"6"<<"7"<<"8";  
44.     ui->cmbDataBits->addItems(dataBitsList);  
45.     ui->cmbDataBits->setCurrentIndex(3);  
46.   
47.     stopBitsList<<"1";  
48.     stopBitsList<<"1.5";  
49.     stopBitsList<<"2";  
50.   
51.     ui->cmbStopBits->addItems(stopBitsList);  
52.     ui->cmbStopBits->setCurrentIndex(0);  
53.   
54.     //Settings button can be pressed  
55.     ui->btnOpen->setCheckable(true);  
56. }  

* Here we add the serial port we need to use to the combox by traversing all the serial ports. If you want to select manually, you can add the serial port name to the combox by listing it, and then select it when you use it.

The serial port settings are as follows:

1. /****************************Serial Port Settings******************************/  
2. void MainWindow::on_btnOpen_clicked()  
3. {  
4.     if(ui->btnOpen->text() == "Open Serial Port")  
5.     {  
6.         my_serialport = new QSerialPort(this);  
7.   
8.         //Set serial number  
9.         my_serialport->setPortName(ui->cmbPortName->currentText());  
10.         //Open Serial Port Read-Write  
11.         if(my_serialport->open(QIODevice::ReadWrite))  
12.         {  
13.             //set baud rate  
14.             my_serialport->setBaudRate(ui->cmbBaudRate->currentText().toInt());  
15.             //set data bit  
16.             my_serialport->setDataBits(QSerialPort::Data8);  
17.             //Set Check Bit  
18.             my_serialport->setParity(QSerialPort::NoParity);  
19.             //set flow control  
20.             my_serialport->setFlowControl(QSerialPort::NoFlowControl);  
21.             //Set stop bits  
22.             my_serialport->setStopBits(QSerialPort::OneStop);  
23.   
24.             //Read once per second  
25.             timer = new QTimer(this);  
26.             connect(timer, SIGNAL(timeout()), this, SLOT(readComDataSlot()));  
27.             timer->start(1000);  
28.   
29.             setNonSelectable();  
30.         }  
31.         else  
32.         {  
33.             QMessageBox::about(NULL, "Tips", "Serial port not open!");  
34.             return;  
35.         }  
36.     }  
37.     else  
38.     {  
39.         timer->stop();  
40.         setSelectable();  
41.         my_serialport->close();  
42.     }  
43. }  

This is the setting of the serial port. You need to open the serial port before you can set the parameters of the serial port.Once the parameters are set, you can read and write the data through the read() and write() functions. I use a 1-second timer here to read the data from the buffer.

The data is sent and received as follows:

1. /****************************Data Transfer************************************/  
2. void MainWindow::readComDataSlot()  
3. {  
4.     //Reading Serial Port Data  
5.     QByteArray readComData = my_serialport->readAll();  
6.   
7.     //Display read data in te of data receiving area  
8.     if(readComData != NULL)  
9.     {  
10.         ui->teReceiveData->append(readComData);  
11.     }  
12.   
13.     //Clear Buffer  
14.     readComData.clear();  
15. }  
16.   
17. void MainWindow::on_btnSend_clicked()  
18. {  
19.     //Get data from the sending area  
20.     QString sendData = ui->teSendData->toPlainText();  
21.     QByteArray sendData_2 = sendData.toLatin1();  
22.   
23.     //Write Buffer  
24.     my_serialport->write(sendData_2);  
25. }