QT serial port programming

1. Classes used

need pro Add modules to QT += serialport

QSerialPort

Common interfaces ：

// Set serial port number
void setPortName(const QString &name)        

// set baud rate
bool setBaudRate(qint32 baudRate, Directions directions = AllDirections)

// set data bit
bool setDataBits(DataBits dataBits)

// Set check bit
bool setParity(Parity parity)

// Set stop bit
bool setStopBits(StopBits stopBits)
 

2. Run a screenshot

3. Source code

#ifndef MAINWIDGET_H
#define MAINWIDGET_H

#include <QWidget>
#include <QSerialPort>
#include <QSerialPortInfo>

namespace Ui {
class MainWidget;
}

class MainWidget : public QWidget
{
    Q_OBJECT

public:
    explicit MainWidget(QWidget *parent = 0);
    ~MainWidget();

private slots:
    void on_btnOpen_clicked();

    void slotReadRead();

private:
    Ui::MainWidget *ui;

private:
    QSerialPort *m_port = nullptr;
};

#endif // MAINWIDGET_H

#include "MainWidget.h"
#include "ui_MainWidget.h"
#include <QMessageBox>
#include <QDebug>
#include <QThread>

MainWidget::MainWidget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::MainWidget)
{
    ui->setupUi(this);

    foreach (const QSerialPortInfo &info, QSerialPortInfo::availablePorts())
    {
        ui->cbxSerialNum->addItem(info.portName());
    }

    QStringList baud;
    baud.append("1800");
    baud.append("2400");
    baud.append("4800");
    baud.append("9600");
    baud.append("19200");
    baud.append("38400");
    baud.append("57600");
    baud.append("115200");
    baud.append("230400");
    ui->cbxBuad->addItems(baud);
    ui->cbxBuad->setCurrentText("115200");

    m_port = new QSerialPort(this);
    connect(m_port,&QSerialPort::readyRead,this,&MainWidget::slotReadRead);
}

MainWidget::~MainWidget()
{
    delete ui;
}

void MainWidget::on_btnOpen_clicked()
{
    if(m_port->isOpen())
    {
        m_port->close();
        ui->btnOpen->setText(" open ");
        return;
    }

    m_port->setPortName(ui->cbxSerialNum->currentText());
    m_port->setBaudRate(ui->cbxBuad->currentText().toInt());
    m_port->setDataBits((QSerialPort::DataBits)ui->cbxDataBit->currentText().toInt());

    if(ui->cbxJybit->currentIndex() == 0)
    {
        m_port->setParity(QSerialPort::NoParity);
    }
    else
    {
        m_port->setParity((QSerialPort::Parity)(ui->cbxJybit->currentIndex()+1));
    }

    m_port->setStopBits((QSerialPort::StopBits)ui->cbxStopBit->currentIndex());

    if(!m_port->open(QIODevice::ReadWrite))
    {
        QMessageBox::critical(NULL,"tips","serial open failed");
    }

    qDebug()<<"serial open success";
    ui->btnOpen->setText(" close ");
}

// When data comes from the serial port , Trigger slot
void MainWidget::slotReadRead()
{
    QByteArray resvBuffer;
    resvBuffer = m_port->readAll();

    qDebug()<<"strlen "<<resvBuffer.size();
    qDebug()<<resvBuffer;
}