serial.cpp

该源码介绍了使用GPS传感器的进行导航系统开发的步骤,包含5个文件,其中Serial.cpp为串口操作 GPSDlg.cpp定义了从GPS传感器中读取位置参数并将位置映射到数字地图上, .BMP为数字

// Serial.cpp : implementation file
//

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

#ifdef _DEBUG
#define new DEBUG_NEW
#undef THIS_FILE
static char THIS_FILE[] = __FILE__;
#endif

BOOL m_bOpened;
HANDLE m_hIDComDev;
OVERLAPPED m_OverlappedRead, m_OverlappedWrite;

/////////////////////////////////////////////////////////////////////////////
// CSerial dialog


CSerial::CSerial(CWnd* pParent /*=NULL*/)
	: CDialog(CSerial::IDD, pParent)
{
	//{{AFX_DATA_INIT(CSerial)
		// NOTE: the ClassWizard will add member initialization here
	//}}AFX_DATA_INIT
}


void CSerial::DoDataExchange(CDataExchange* pDX)
{
	CDialog::DoDataExchange(pDX);
	//{{AFX_DATA_MAP(CSerial)
		// NOTE: the ClassWizard will add DDX and DDV calls here
	//}}AFX_DATA_MAP
}


BEGIN_MESSAGE_MAP(CSerial, CDialog)
	//{{AFX_MSG_MAP(CSerial)
		// NOTE: the ClassWizard will add message map macros here
	//}}AFX_MSG_MAP
END_MESSAGE_MAP()

/////////////////////////////////////////////////////////////////////////////
// CSerial message handlers

BOOL CSerial::Open( int nPort, int nBaud ,char nParity,int nDatabits,int nStopbits)
{
	char szPort[15];
	char szComParams[50];
	DCB dcb;
	unsigned char ucSet;
	COMMTIMEOUTS CommTimeOuts;
	

	if( m_bOpened ) return( TRUE );


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

	wsprintf( szComParams, "COM%d:%d,%c,%d,%d", nPort, nBaud ,nParity,nDatabits,nStopbits);

	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;
	dcb.st

	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 );

}

int CSerial::ReadDataWaiting( void )
{
	DWORD dwErrorFlags;
	COMSTAT ComStat;

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



	ClearCommError( m_hIDComDev, &dwErrorFlags, &ComStat );

	return( (int) ComStat.cbInQue );

}

int CSerial::ReadData( void *buffer, int limit )
{
	BOOL bReadStatus;
	DWORD dwBytesRead, dwErrorFlags;
	COMSTAT ComStat;

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



	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 );

}