Realizing the communication between PIC microcontroller and QT host computer based on RS232 serial port

Introduction: The host computer sends a message to the slave computer through the RS232 serial port. The slave computer receives the message and performs two actions:

(1) LED light changes.

(2) Return the message to the host computer through the RS232 serial port;

After receiving the message, the host computer displays the content on the UI interface.

Windows7 64-bit environment complete source code and source program package download: https://download.csdn.net/download/robin_xx/10791050

The main code is pasted below:

PIC microcontroller lower machine source program:

#include

__CONFIG(HS&WDTDIS&LVPDIS);

unsigned char i=0;

//void interrupt ISR(void);

void interrupt usart(void);

void Init(void); //initialization

unsigned char* sendData="";

const unsigned char led10[]=//8 LED running lights code table

    {

        0B00000000,

        0B00000001,

        0B00000010,

        0B00000100,

        0B00001000,

        0B00010000,

        0B00100000,

        0B01000000,

        0B10000000,

        0B11111111

    };

void main(void)

{

    Init();

    while(1)

    {

        if (i==10)

            i=0;

        PORTB=led10[i];

    }

}

/*void interrupt ISR(void)//

{

    if(INTF==1)//button interrupt

    {

        INTF=0; // clear interrupt flag

        i+=1; //Each time an interrupt occurs, the running light starts lighting up from the beginning

    }

}*/

void interrupt usart(void)

{

    if(RCIE&&RCIF) //Judge whether it is a serial port receiving interrupt

    {

        i+=1;

        while(!TRMT); //Wait for acceptance

        sendData=RCREG; 

        //i=sendData;

    }

    if(sendData!="")

    {    

        RCIE=0; //Turn off the receive interrupt enable bit before sending

        TXREG = sendData; //Send the received data back

        while(!TXIF); //Wait for sending to complete

        RCIE = 1; //Send completed, enable receive interrupt enable bit

        sendData="";

    }

}

void Init(void)

{

    TRISB=0B00000000; //control 8 LEDs, output port

    PORTB=0B00000000;//

    // Initialize port program

    TRISC7 = 1; //RX port is set to input valid

    TRISC6 = 0; //TX port is set to output valid

    //SPBRG = 0X19; //Set the baud rate to 9600BPS

    SPBRG = 0XC; //Set the baud rate to 19200BPS

    //TXSTA = 0x04; //Asynchronous communication - prohibit sending data - high speed mode

    TXSTA = 0X24; // Enable serial port transmission and select high-speed baud rate

    //RCSTA = 0xA0; //Serial port enable - receive single character - disable continuous reception

    RCSTA = 0X90; // Enable serial port operation and continuous reception

    RCIE=0X1; //Enable receive interrupt

    GIE=0X1; //Open global interrupt

    PEIE=0X1; //Enable external interrupt

}

QT host computer source program:

mainwindow.h

#ifndef MAINWINDOW_H

#define MAINWINDOW_H

#include

#include

#include

namespace Ui {

class MainWindow;

}

class MainWindow : public QMainWindow

{

    Q_OBJECT

public:

    QSerialPort *serial;

    explicit MainWindow(QWidget *parent = 0);

    ~MainWindow();

private slots:

    void on_pushButton_send_clicked();

    void on_pushButton_openPort_clicked();

    void read_Com();

    void on_pushButton_ClearRec_clicked();

private:

    Ui::MainWindow *ui;

};

#endif // MAINWINDOW_H

mainwindow.cpp

#include "mainwindow.h"

#include "ui_mainwindow.h"

MainWindow::MainWindow(QWidget *parent) :

    QMainWindow(parent),

    ui(new Ui::MainWindow)

{

    ui->setupUi(this);

    foreach (const QSerialPortInfo &info, QSerialPortInfo::availablePorts())

    {

        QSerialPort serial;

        serial.setPort(info);

        //Judge whether the serial port can be opened

        if (serial.open(QIODevice::ReadWrite))

        {

            QString portStr = info.portName();

            ui->comboBox_portList->addItem(portStr);

            serial.close();

        }

     }

    ui->comboBox_portList->setCurrentIndex(0);

    ui->comboBox_BPS->addItem("7200");

    ui->comboBox_BPS->addItem("9600");

    ui->comboBox_BPS->addItem("14400");

    ui->comboBox_BPS->addItem("19200");

    ui->comboBox_BPS->addItem("38400");

    ui->comboBox_BPS->addItem("57600");

    ui->comboBox_BPS->setCurrentIndex(3);

    on_pushButton_openPort_clicked();

    on_pushButton_openPort_clicked();

}

MainWindow::~MainWindow()

{

    delete ui;

}

//Read the received information

 void MainWindow::read_Com()

 {

     QByteArray temp=serial->readAll();

     if(!temp.isEmpty()) //If the read data is not empty

     {

         ui->textBrowser_RecList->insertPlainText(temp);

     }

 }

//Send button slot function

void MainWindow::on_pushButton_send_clicked()

{

    QString str=ui->lineEdit_sendText->text(); //Get string from LineEdit

    if(str!="")

    {

        ui->textBrowser_RecList->insertPlainText("n");

        serial->write(str.toLatin1()); //Write data to the serial port in ASCII code

        //ui->lineEdit_sendText->clear();

    }

}

void MainWindow::on_pushButton_openPort_clicked()

{

    if(ui->comboBox_portList->isEnabled())

     {

        ui->pushButton_openPort->setText("ClosePort"); //After pressing "OpenPort", the button displays "ClosePort"

        ui->comboBox_portList->setDisabled(true); //After pressing "OpenPort", it is forbidden to modify the COM port

        serial = new QSerialPort;

        //Set the serial port name

        serial->setPortName(ui->comboBox_portList->currentText());

        ui->textBrowser_RecList->insertPlainText("nNowPort:"+ui->comboBox_portList->currentText());

        //Method to automatically find available serial ports

        //Close the serial port first, then open it to ensure that the serial port is not occupied by other functions.

        //serial->close();

        //Open the serial port

        serial->open(QIODevice::ReadWrite);

        //Set the baud rate

        serial->setBaudRate(ui->comboBox_BPS->currentText().toInt());

        ui->comboBox_BPS->setDisabled(true);

         //Set the number of data bits (8)

         serial->setDataBits(QSerialPort::Data8);

        //Set the check bit (such as 0)

         serial->setParity(QSerialPort::NoParity);

        //Set the stop bit (such as 1)

         serial->setStopBits(QSerialPort::OneStop);

        //Set flow control (none)

         serial->setFlowControl(QSerialPort::NoFlowControl);

         //Bind the serial port's readyRead() signal to the read_Com() slot function

         connect(serial,SIGNAL(readyRead()),this,SLOT(read_Com()));

    }

    else

    {

        ui->pushButton_openPort->setText("OpenPort"); //After pressing "ClosePort", the button displays "OpenPort"

        ui->comboBox_portList->setEnabled(true); //After pressing "ClosePort", the COM port can be modified

        ui->comboBox_BPS->setEnabled(true);

        serial->close(); //Close the serial port

    }

}

void MainWindow::on_pushButton_ClearRec_clicked()

{

    ui->textBrowser_RecList->clear();

}

main.cpp

#include "mainwindow.h"

#include

int main(int argc, char *argv[])

{

    QApplication a(argc, argv);

    MainWindow w;

    w.show();

    return a.exec();

}

UI interface:

Windows7 64-bit environment complete source code and source program package download: https://download.csdn.net/download/robin_xx/10791050