qt实现串口通讯

摘要：上位机软件程序通过QT实现，采集输入信息，根据实际需要做出合适的串口通讯协议，实现效果如下图所示：

 主要实现的功能：

1.串口基本参数可选，可调

2.显示区域可选择十六进制/asicii码显示，可根据自己的需求调整多少字节对齐，显示的比较工整，有利于解析协议

3.可自己制定协议头，其他子项内容都是以十进制输入，内置checksum自动计算

4.实时显示发送/接收字节数

5.可自己定制时间周期定时发送

6.实时显示时间

代码实现：

实现过程较为简单，主要是协议处理：

串口设备：新建串口对象 -> 寻找可用串口设置 -> 设置串口基本参数 -> 打开串口 ->监听串口

串口协议：LineEdit的内容是大端格式，所以使用的时候要将变量转换成大端，默认是小端

注意：

QString("%1").arg(ui>lineEdit_S_num>text().toInt(),8,16,QChar('0'))

第一个参数 : 将Qstring转换为int型4 第二个参数 : 需要将几个字符串转换成十六进制的，
如char型   ：需要两个字符
   short型  : 需要四个字符
   int/long : 需要八个字符
第三个参数:  转换为多少进制
第四个参数:  不足位数的用0补齐

//QByteArray里面的数据按照对应的通讯协议进行调整
void Widget::int_adjust(QByteArray  &str,qint8 startcount)
{
    qint8 temp1;
    qint8 temp2;
    temp1 = str[startcount];
    temp2 = str[startcount+1];
    str[startcount] = str[startcount+3];
    str[startcount+1] = str[startcount+2];
    str[startcount+2] =temp2;
    str[startcount+3] =temp1;
}
void Widget::short_adjust(QByteArray  &str,qint8 startcount)
{
    qint8 temp1;
    temp1 = str[startcount];
    str[startcount] = str[startcount+1];
    str[startcount+1] = temp1;
}

//字符串转成十六进制实现
void Widget::StringToHex(QString str, QByteArray &senddata)
{

    int hexdata,lowhexdata;

    int hexdatalen = 0;

    int len = str.length();

    senddata.resize(len/2);

    char lstr,hstr;

    for(int i=0; i<len; )
    {
        //char lstr,
        hstr=str[i].toLatin1();
        if(hstr == ' ')
        {
            i++;
            continue;
        }
        i++;
        if(i >= len)
           break;
        lstr = str[i].toLatin1();
        hexdata = ConvertHexChar(hstr);
        lowhexdata = ConvertHexChar(lstr);
        if((hexdata == 16) || (lowhexdata == 16))
            break;
        else
            hexdata = hexdata*16+lowhexdata;
        i++;
        senddata[hexdatalen] = (char)hexdata;
        hexdatalen++;
    }
    senddata.resize(hexdatalen);
}


char Widget::ConvertHexChar(char ch)
{
   if((ch >= '0') && (ch <= '9'))
            return ch-0x30;
        else if((ch >= 'A') && (ch <= 'F'))
           return ch-'A'+10;
        else if((ch >= 'a') && (ch <= 'f'))
            return ch-'a'+10;
        else return (-1);


}

 要点，易错点基本已经指出,其他的比较简单，这里不再赘叙

#include "widget.h"
#include "ui_widget.h"
#include <QTimer>
#include <QDateTime>
#include <QMessageBox>
static int CountBase = 0;
static int SENDNUMSIZE = 20;
static int recvCount = 0;
Widget::Widget(QWidget *parent) :
    QWidget(parent),
    ui(new Ui::Widget)
{
    ui->setupUi(this);
    serial = new QSerialPort;
    /* regester software timer*/
    atimer = new QTimer();
    atimer->setInterval(1000);
    atimer->start();

    cycletime = new QTimer();
    cycletime->setInterval(ui->lineEdit_cycletime->text().toInt());

    QObject::connect(atimer,&QTimer::timeout,this,&Widget::timer_handle);

        //查找可用的串口
           foreach (const QSerialPortInfo &info,QSerialPortInfo::availablePorts())
           {
               QSerialPort serial;
               serial.setPort(info);
               if(serial.open(QIODevice::ReadWrite))
               {
                   ui->comBox->addItem(serial.portName());
                   serial.close();
               }
           }
           //设置波特率下拉菜单默认显示第0项
           ui->baudBox->setCurrentIndex(0);
           ui->baudBox->setEnabled(false);
           ui->stopbitBox->setEnabled(false);
           ui->databitBox->setEnabled(false);
           ui->checkBox->setEnabled(false);
           ui->comBox->setEnabled(false);
}

Widget::~Widget()
{
    delete ui;
}
void Widget::timer_handle(void)
{

    QDateTime current_date_time =QDateTime::currentDateTime();
    QString current_date =current_date_time.toString("yyyy.MM.dd hh:mm:ss ddd");
   // ui->textBrowser_date
    ui->label_date->setText(current_date);

}

void Widget::on_pushButton_oprea_clicked()
{
    if(ui->pushButton_oprea->text() == tr("串口已关闭"))
        {
            serial = new QSerialPort;
            //设置串口名
            serial->setPortName(ui->comBox->currentText());
            //打开串口
            serial->open(QIODevice::ReadWrite);
            //设置波特率
            serial->setBaudRate(QSerialPort::Baud115200);//设置波特率为115200
            //设置数据位数
            switch (ui->databitBox->currentIndex())
            {
            case 0:
                serial->setDataBits(QSerialPort::Data8);//设置数据位8
                break;
            default:
                break;
            }
            //设置校验位
            switch (ui->checkBox->currentIndex())
            {
            case 0:
                serial->setParity(QSerialPort::NoParity);
                break;
            default:
                break;
            }
            //设置停止位
            switch (ui->stopbitBox->currentIndex())
            {
            case 0:
                serial->setStopBits(QSerialPort::OneStop);//停止位设置为1
                break;
            case 1:
                serial->setStopBits(QSerialPort::TwoStop);
            default:
                break;
            }
            //设置流控制
            serial->setFlowControl(QSerialPort::NoFlowControl);//设置为无流控制

            //关闭设置菜单使能
            ui->baudBox->setEnabled(true);
            ui->stopbitBox->setEnabled(true);
            ui->databitBox->setEnabled(true);
            ui->checkBox->setEnabled(true);
            ui->comBox->setEnabled(true);
            ui->pushButton_oprea->setText(tr("串口已打开"));

            //连接信号槽
            QObject::connect(serial,&QSerialPort::readyRead,this,&Widget::ReadData);
        }
        else
        {
            cycletime->stop();
            //关闭串口
            serial->clear();
            serial->close();
            serial->deleteLater();

            //恢复设置使能
            ui->baudBox->setEnabled(false);
            ui->stopbitBox->setEnabled(false);
            ui->databitBox->setEnabled(false);
            ui->checkBox->setEnabled(false);
            ui->comBox->setEnabled(false);
            ui->pushButton_oprea->setText(tr("串口已关闭"));
        }
}
//读取接收到的信息
void Widget::ReadData()
{
     QByteArray temp;
    if(ui->HEX_SHOW->isChecked())
    {
       SENDNUMSIZE = ui->lineEdit_duiqi->text().toInt();
       temp = serial->readAll();
        QDataStream out(&temp,QIODevice::ReadWrite);    //将字节数组读入
            while(!out.atEnd())
            {
                qint8 outChar = 0;
                static qint8 datacount = 1;
                recvCount++;
                out>>outChar;   //每字节填充一次，直到结束
                datacount++;
                //十六进制的转换
                QString str = QString(" %1").arg(outChar&0xFF,2,16,QLatin1Char('0'));
                ui->textBrowser->insertPlainText(str);
                ui->label_recvvalue->setNum(recvCount);
                if(SENDNUMSIZE+2 == datacount)
                {
                    datacount = 1;
                    ui->textBrowser->insertPlainText("
");
                     ui->textBrowser->moveCursor(QTextCursor::End);
                }
            }
    }
    else
    {

        temp += serial->readAll();
        if(!temp.isEmpty())
        {
            ui->textBrowser->append(temp);
            ui->textBrowser->moveCursor(QTextCursor::End);
        }
        temp.clear();
    }

}
 short Widget::checksum(QByteArray ba)
{
    short i = 0,sumValue = 0;

    for(i=2;i<(ba.length());i++)
    {
        sumValue+=ba.at(i);
    }
    return sumValue;
}

void Widget::on_send_clicked()
{
    short checkValue = 0;
    QString str;
    QByteArray senddata;
    if(ui->pushButton_oprea->text() == tr("串口已关闭"))
    {
        QMessageBox::information(this, "warning", "串口没打开", QMessageBox::Yes);

    }
    if(ui->radio_dash->isChecked())
    {
         str =  ui->lineEdit_head->text()
                + QString("%1").arg(ui->lineEdit_infopage->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_menu->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_speed->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_FP->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_BP->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_gear->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_hour->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_minute->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_TemP->text().toShort(),4,16,QChar('0'))//10
                + QString("%1").arg(ui->lineEdit_trip->text().toShort(),4,16,QChar('0'))//12
                + QString("%1").arg(ui->lineEdit_C_Trip->text().toShort(),4,16,QChar('0'))//14
                + QString("%1").arg(ui->lineEdit_odo->text().toInt(),8,16,QChar('0'))//16
                + QString("%1").arg(ui->lineEdit_LF_Press->text().toShort(),4,16,QChar('0'))//20
                + QString("%1").arg(ui->lineEdit_LB_Press->text().toShort(),4,16,QChar('0'))//22
                + QString("%1").arg(ui->lineEdit_RF_Press->text().toShort(),4,16,QChar('0'))//24
                + QString("%1").arg(ui->lineEdit_RB_Press->text().toShort(),4,16,QChar('0'))//26
                + QString("%1").arg(ui->lineEdit_oil_cost->text().toInt(),8,16,QChar('0'))//28
                + QString("%1").arg(ui->lineEdit_C_oilcost->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_AV_oil_cost->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_can_warning->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_icon->text().toShort(),4,16,QChar('0'))//35
                + QString("%1").arg(ui->lineEdit_backlight->text().toShort(),2,16,QChar('0'));
                 /*************** 调整short 和 init 数据类型字节发送顺序 ****************/
                 StringToHex(str,senddata);//将str字符串转换为16进制的形式
                 short_adjust(senddata,10);
                 short_adjust(senddata,12);
                 short_adjust(senddata,14);
                 int_adjust(senddata,16);
                 short_adjust(senddata,20);
                 short_adjust(senddata,22);
                 short_adjust(senddata,24);
                 short_adjust(senddata,26);
                 int_adjust(senddata,28);
                 short_adjust(senddata,35);
         }
    else{
         str =  ui->lineEdit_head->text()
                + QString("%1").arg(ui->lineEdit_ST_Page->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_menu_level->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_cursor->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_C_selcet->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_num->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_S_num->text().toInt(),8,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_S_hour->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_S_minute->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_S_year->text().toShort(),4,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_S_month->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_S_day->text().toShort(),2,16,QChar('0'))
                + QString("%1").arg(ui->lineEdit_S_backlight->text().toShort(),2,16,QChar('0'));
                 /*************** 调整short 和 init 数据类型字节发送顺序 ****************/
                 StringToHex(str,senddata);//将str字符串转换为16进制的形式
                 int_adjust(senddata,7);
                 short_adjust(senddata,13);
    }


    checkValue = checksum(senddata);
    senddata.append((char)(checkValue));
    serial->write(senddata);//发送到串口
    CountBase+=senddata.length();

    ui->label_sendvalue->setNum(CountBase);
 }
void Widget::int_adjust(QByteArray  &str,qint8 startcount)
{
    qint8 temp1;
    qint8 temp2;
    temp1 = str[startcount];
    temp2 = str[startcount+1];
    str[startcount] = str[startcount+3];
    str[startcount+1] = str[startcount+2];
    str[startcount+2] =temp2;
    str[startcount+3] =temp1;
}
void Widget::short_adjust(QByteArray  &str,qint8 startcount)
{
    qint8 temp1;
    temp1 = str[startcount];
    str[startcount] = str[startcount+1];
    str[startcount+1] = temp1;
}

void Widget::StringToHex(QString str, QByteArray &senddata)
{

    int hexdata,lowhexdata;

    int hexdatalen = 0;

    int len = str.length();

    senddata.resize(len/2);

    char lstr,hstr;

    for(int i=0; i<len; )
    {
        //char lstr,
        hstr=str[i].toLatin1();
        if(hstr == ' ')
        {
            i++;
            continue;
        }
        i++;
        if(i >= len)
           break;
        lstr = str[i].toLatin1();
        hexdata = ConvertHexChar(hstr);
        lowhexdata = ConvertHexChar(lstr);
        if((hexdata == 16) || (lowhexdata == 16))
            break;
        else
            hexdata = hexdata*16+lowhexdata;
        i++;
        senddata[hexdatalen] = (char)hexdata;
        hexdatalen++;
    }
    senddata.resize(hexdatalen);
}


char Widget::ConvertHexChar(char ch)
{
   if((ch >= '0') && (ch <= '9'))
            return ch-0x30;
        else if((ch >= 'A') && (ch <= 'F'))
           return ch-'A'+10;
        else if((ch >= 'a') && (ch <= 'f'))
            return ch-'a'+10;
        else return (-1);


}


void Widget::on_pushButton_clicked()
{
    ui->textBrowser->clear();
    CountBase = 0;
    ui->label_sendvalue->setNum(0);
    recvCount = 0;
     ui->label_recvvalue->setNum(0);
}
void  Widget::cycletime_handle(void)
{
    on_send_clicked();
}
void Widget::on_lineEdit_duiqi_editingFinished()
{
    SENDNUMSIZE = ui->lineEdit_duiqi->text().toInt();
}

void Widget::on_checkBox_TIMER_stateChanged(int arg1)
{
    if(ui->checkBox_TIMER->isChecked())
    {
        cycletime->start();
        QObject::connect(cycletime,&QTimer::timeout,this,&Widget::cycletime_handle);
    }
    else
    {
        cycletime->stop();
    }

}