Serial communication between pc and Arduino through USB

问题

I have some C++ code that I need to use for serial communication between PC and Arduino. The file "Serial.cpp" is including a file called "stdafx.h" that doesn't exist in the project or anywhere on my computer, which obviously causes an error. Other than that, I also get other errors, such as C2065 'CSerial': undeclared identifier.

Here are the three files that are in the project:

Serial.h

#ifndef __SERIAL_H__
#define __SERIAL_H__
#pragma once

#include <Windows.h>
#include <memory.h>

#define FC_DTRDSR       0x01
#define FC_RTSCTS       0x02
#define FC_XONXOFF      0x04
#define ASCII_BEL       0x07
#define ASCII_BS        0x08
#define ASCII_LF        0x0A
#define ASCII_CR        0x0D
#define ASCII_XON       0x11
#define ASCII_XOFF      0x13

class CSerial
{

public:
    CSerial();
    ~CSerial();

    BOOL Open( int nPort = 2, int nBaud = 9600 );
    BOOL Close( void );

    int ReadData( void *, int );
    int SendData( const char *, int );
    int ReadDataWaiting( void );

    BOOL IsOpened( void ){ return( m_bOpened ); }

protected:
    BOOL WriteCommByte( unsigned char );

    HANDLE m_hIDComDev;
    OVERLAPPED m_OverlappedRead, m_OverlappedWrite;
    bool m_bOpened;

};

#endif

Serial.cpp

// Serial.cpp

#include "stdafx.h"
#include "Serial.h"


CSerial::CSerial()
{

    memset( &m_OverlappedRead, 0, sizeof( OVERLAPPED ) );
    memset( &m_OverlappedWrite, 0, sizeof( OVERLAPPED ) );
    m_hIDComDev = NULL;
    m_bOpened = false;

}

CSerial::~CSerial()
{

    Close();

}

BOOL CSerial::Open( int nPort, int nBaud )
{

    if( m_bOpened ) return( TRUE );

    wchar_t szPort[15];
    wchar_t szComParams[50];
    DCB dcb;

    wsprintf( szPort, L"COM%d", nPort );
    m_hIDComDev = CreateFile( szPort, GENERIC_READ | GENERIC_WRITE, 0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED, NULL );
    if( m_hIDComDev == NULL ) return( FALSE );

    memset( &m_OverlappedRead, 0, sizeof( OVERLAPPED ) );
    memset( &m_OverlappedWrite, 0, sizeof( OVERLAPPED ) );

    COMMTIMEOUTS CommTimeOuts;
    CommTimeOuts.ReadIntervalTimeout = 0xFFFFFFFF;
    CommTimeOuts.ReadTotalTimeoutMultiplier = 0;
    CommTimeOuts.ReadTotalTimeoutConstant = 0;
    CommTimeOuts.WriteTotalTimeoutMultiplier = 0;
    CommTimeOuts.WriteTotalTimeoutConstant = 5000;
    SetCommTimeouts( m_hIDComDev, &CommTimeOuts );

    wsprintf( szComParams, L"COM%d:%d,n,8,1", nPort, nBaud );

    m_OverlappedRead.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );
    m_OverlappedWrite.hEvent = CreateEvent( NULL, TRUE, FALSE, NULL );

    dcb.DCBlength = sizeof( DCB );
    GetCommState( m_hIDComDev, &dcb );
    dcb.BaudRate = nBaud;
    dcb.ByteSize = 8;
    unsigned char ucSet;
    ucSet = (unsigned char) ( ( FC_RTSCTS & FC_DTRDSR ) != 0 );
    ucSet = (unsigned char) ( ( FC_RTSCTS & FC_RTSCTS ) != 0 );
    ucSet = (unsigned char) ( ( FC_RTSCTS & FC_XONXOFF ) != 0 );
    if( !SetCommState( m_hIDComDev, &dcb ) ||
        !SetupComm( m_hIDComDev, 10000, 10000 ) ||
        m_OverlappedRead.hEvent == NULL ||
        m_OverlappedWrite.hEvent == NULL ){
        DWORD dwError = GetLastError();
        if( m_OverlappedRead.hEvent != NULL ) CloseHandle( m_OverlappedRead.hEvent );
        if( m_OverlappedWrite.hEvent != NULL ) CloseHandle( m_OverlappedWrite.hEvent );
        CloseHandle( m_hIDComDev );
        return( FALSE );
        }

    m_bOpened = TRUE;

    return( m_bOpened );

}

BOOL CSerial::Close( void )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( TRUE );

    if( m_OverlappedRead.hEvent != NULL ) CloseHandle( m_OverlappedRead.hEvent );
    if( m_OverlappedWrite.hEvent != NULL ) CloseHandle( m_OverlappedWrite.hEvent );
    CloseHandle( m_hIDComDev );
    m_bOpened = FALSE;
    m_hIDComDev = NULL;

    return( TRUE );

}

BOOL CSerial::WriteCommByte( unsigned char ucByte )
{
    BOOL bWriteStat;
    DWORD dwBytesWritten;

    bWriteStat = WriteFile( m_hIDComDev, (LPSTR) &ucByte, 1, &dwBytesWritten, &m_OverlappedWrite );
    if( !bWriteStat && ( GetLastError() == ERROR_IO_PENDING ) ){
        if( WaitForSingleObject( m_OverlappedWrite.hEvent, 1000 ) ) dwBytesWritten = 0;
        else{
            GetOverlappedResult( m_hIDComDev, &m_OverlappedWrite, &dwBytesWritten, FALSE );
            m_OverlappedWrite.Offset += dwBytesWritten;
            }
        }

    return( TRUE );

}

int CSerial::SendData( const char *buffer, int size )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );

    DWORD dwBytesWritten = 0;
    int i;
    for( i=0; i<size; i++ ){
        WriteCommByte( buffer[i] );
        dwBytesWritten++;
        }

    return( (int) dwBytesWritten );

}

int CSerial::ReadDataWaiting( void )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );

    DWORD dwErrorFlags;
    COMSTAT ComStat;

    ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );

    return( (int) ComStat.cbInQue );

}

int CSerial::ReadData( void *buffer, int limit )
{

    if( !m_bOpened || m_hIDComDev == NULL ) return( 0 );

    BOOL bReadStatus;
    DWORD dwBytesRead, dwErrorFlags;
    COMSTAT ComStat;

    ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );
    if( !ComStat.cbInQue ) return( 0 );

    dwBytesRead = (DWORD) ComStat.cbInQue;
    if( limit < (int) dwBytesRead ) dwBytesRead = (DWORD) limit;

    bReadStatus = ReadFile( m_hIDComDev, buffer, dwBytesRead, &dwBytesRead, &m_OverlappedRead );
    if( !bReadStatus ){
        if( GetLastError() == ERROR_IO_PENDING ){
            WaitForSingleObject( m_OverlappedRead.hEvent, 2000 );
            return( (int) dwBytesRead );
            }
        return( 0 );
        }

    return( (int) dwBytesRead );

}

SerialExample.cpp

bool sendExample(int port, int baudRate)
{
    char data[4];

    CSerial* s = new CSerial();

    if(!s->Open(port, baudRate))
    {
        std_out << _T("Could not open COM") << port << endl;
        return false;
    }


    // Sending a string of 4 characters
    data[0] = 0x31; 
    data[1] = 0x32;
    data[2] = 0x33;
    data[3] = 0x0D; // ASCII CR
    s->SendData(data, 4);

    s->Close();

    delete s;

}

Does anyone know what I have to do?

回答1:

stdafx.h is a precompiled header for Visual studio. so if you are not working in visual studio, you can just remove it and it should work just fine.

In regard to the compiler not recognizing the CSerial class - I don't see where you include "CSerial.h" in SerialExample.cpp (i.e: #include "CSerial.h"), but if you do, this may also be a symptom of CSerial.cpp not compiling (less likely though)...

Hope this helps, Lior

来源：https://stackoverflow.com/questions/59139479/serial-communication-between-pc-and-arduino-through-usb