serialport.cpp

windows 下串口编程。 实现串口收发

#include "stdafx.h"
#include "SerialPort.h"

#include <assert.h>

 
//
// Constructor
//
CSerialPort::CSerialPort()
{
	m_hComm = NULL;

	// initialize overlapped structure members to zero
	m_ov.Offset = 0;
	m_ov.OffsetHigh = 0;

	// create events
	m_ov.hEvent = NULL;
	m_hWriteEvent = NULL;
	m_hShutdownEvent = NULL;

	m_szWriteBuffer = NULL;
	m_nWriteSize=1;

	m_bThreadAlive = FALSE;
}

//
// Delete dynamic memory
//
CSerialPort::~CSerialPort()
{
	do
	{
		SetEvent(m_hShutdownEvent);
	} while (m_bThreadAlive);


	TRACE("Thread ended\n");

	delete [] m_szWriteBuffer;
}

//
// Initialize the port. This can be port 1 to 4.
//
BOOL CSerialPort::InitPort(CWnd* pPortOwner,	// the owner (CWnd) of the port (receives message)
						   CString str_SerialPort,	// portnumber (1..4) portnr
						   int  baud,			// baudrate
						   int  parityBit,		// parity 
						   int  dataBits,		// databits 
						   int  stopBits,		// stopbits 
						   DWORD dwCommEvents,	// EV_RXCHAR, EV_CTS etc
						   UINT  writebuffersize)	// size to the writebuffer
{
//	assert(portnr > 0 && portnr < 5);
//	assert(pPortOwner != NULL);

//	CString str_SerialPort = portnr;
	// if the thread is alive: Kill
	if (m_bThreadAlive)
	{
		do
		{
			SetEvent(m_hShutdownEvent);
		} while (m_bThreadAlive);
		TRACE("Thread ended\n");
	}

	// create events
	if (m_ov.hEvent != NULL)
		ResetEvent(m_ov.hEvent);
	m_ov.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

	if (m_hWriteEvent != NULL)
		ResetEvent(m_hWriteEvent);
	m_hWriteEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
	
	if (m_hShutdownEvent != NULL)
		ResetEvent(m_hShutdownEvent);
	m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

	// initialize the event objects
	m_hEventArray[0] = m_hShutdownEvent;	// highest priority
	m_hEventArray[1] = m_ov.hEvent;
	m_hEventArray[2] = m_hWriteEvent;

	// initialize critical section
	InitializeCriticalSection(&m_csCommunicationSync);
	
	// set buffersize for writing and save the owner
	m_pOwner = pPortOwner;

	if (m_szWriteBuffer != NULL)
		delete [] m_szWriteBuffer;
	m_szWriteBuffer = new char[writebuffersize];

	//m_nPortNr = portnr;

	m_nWriteBufferSize = writebuffersize;
	m_dwCommEvents = dwCommEvents;

	BOOL bResult = FALSE;
//	char *szPort = new char[50];
//	char *szBaud = new char[50];

	// now it critical!
	EnterCriticalSection(&m_csCommunicationSync);

	// if the port is already opened: close it
	if (m_hComm != NULL)
	{
		CloseHandle(m_hComm);
		m_hComm = NULL;
	}

	// 打开串口
	if (!OpenSerialPort(str_SerialPort))
		return FALSE;

	// 配置串口
	if (!ConfigSeriport(baud, parityBit, dataBits, stopBits))
		return FALSE;

/*	// prepare port strings
	sprintf(szPort, "COM%d", portnr);
	sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, stopbits);

	// get a handle to the port
	m_hComm = CreateFile(szPort,						// communication port string (COMX)
					     GENERIC_READ | GENERIC_WRITE,	// read/write types
					     0,								// comm devices must be opened with exclusive access
					     NULL,							// no security attributes
					     OPEN_EXISTING,					// comm devices must use OPEN_EXISTING
					     FILE_FLAG_OVERLAPPED,			// Async I/O
					     0);							// template must be 0 for comm devices

	if (m_hComm == INVALID_HANDLE_VALUE)
	{
		// port not found
		delete [] szPort;
		delete [] szBaud;

		return FALSE;
	}

	// set the timeout values
	m_CommTimeouts.ReadIntervalTimeout = 1000;
	m_CommTimeouts.ReadTotalTimeoutMultiplier = 1000;
	m_CommTimeouts.ReadTotalTimeoutConstant = 1000;
	m_CommTimeouts.WriteTotalTimeoutMultiplier = 1000;
	m_CommTimeouts.WriteTotalTimeoutConstant = 1000;

	// configure
	if (SetCommTimeouts(m_hComm, &m_CommTimeouts))
	{						   
		if (SetCommMask(m_hComm, dwCommEvents))
		{
			if (GetCommState(m_hComm, &m_dcb))
			{
				m_dcb.EvtChar = 'q';
				m_dcb.fRtsControl = RTS_CONTROL_ENABLE;		// set RTS bit high!
				if (BuildCommDCB(szBaud, &m_dcb))
				{
					if (SetCommState(m_hComm, &m_dcb))
						; // normal operation... continue
					else
						ProcessErrorMessage("SetCommState()");
				}
				else
					ProcessErrorMessage("BuildCommDCB()");
			}
			else
				ProcessErrorMessage("GetCommState()");
		}
		else
			ProcessErrorMessage("SetCommMask()");
	}
	else
		ProcessErrorMessage("SetCommTimeouts()");

	delete [] szPort;
	delete [] szBaud;

	// flush the port
	PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);

	// release critical section
	LeaveCriticalSection(&m_csCommunicationSync);

	TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr);
*/
	return TRUE;
}


BOOL CSerialPort::OpenSerialPort(CString str_SerialPort){

//		CString str_SerialPort;     //串口号

	if(str_SerialPort) {

		LPCSTR port = str_SerialPort;


		// get a handle to the port
		m_hComm = CreateFile(str_SerialPort,						// communication port string (COMX)
					     GENERIC_READ | GENERIC_WRITE,	// read/write types
					     0,								// comm devices must be opened with exclusive access
					     NULL,							// no security attributes
					     OPEN_EXISTING,					// comm devices must use OPEN_EXISTING
					     FILE_FLAG_OVERLAPPED,			// Async I/O
					     0);						// template must be 0 for comm devices
	}

	if(m_hComm == INVALID_HANDLE_VALUE)
		return FALSE;

	// flush the port
	PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);

	// release critical section
	LeaveCriticalSection(&m_csCommunicationSync);


	return TRUE;
}

BOOL CSerialPort::ConfigSeriport(int baud, int parityBit, int dataBits, int stopBits ) {


//	int int_Baud = 9600;     //波特率
//	int int_DataBits = 8; //数据位
//	int int_Parity = 1;   //校验位
//	int int_StopBits = 2; //停止位
//	int int_FlowCtrl; //流控制选项
//	BOOL b_EnabParity = FALSE; // 奇偶校验使能

	if(m_hComm == INVALID_HANDLE_VALUE)
		return FALSE;
	if(!GetCommState(m_hComm, &m_dcb))
		return FALSE;

//	m_dcb.fBinary = TRUE; // 二进制传输
//	m_dcb.BaudRate = int_Baud; // 波特率
//	m_dcb.ByteSize = int_DataBits; // 数据位数
//	m_dcb.fParity = b_EnabParity; // 奇偶校验使能位

	m_dcb.fBinary=TRUE; // 二进制传输
	m_dcb.BaudRate = baud; // 波特率
	m_dcb.ByteSize = dataBits; // 数据位数
	m_dcb.fParity = TRUE; // 奇偶校验位

	switch(parityBit) // 校验设置
	{
	case 0: 
		m_dcb.Parity=NOPARITY; // 无奇偶校验
		break;

	case 1: 
		m_dcb.Parity=EVENPARITY; // 偶校验
		break;

	case 2: 
		m_dcb.Parity=ODDPARITY; // 奇校验
		break;
	default:;	// 默认（不设定）
	}

	switch(stopBits) // 停止位
	{
	case 0: 
		m_dcb.StopBits=ONESTOPBIT; // 1
		break;

	case 1: 
		m_dcb.StopBits=ONE5STOPBITS; // 1.5
		break;

	case 2:
		m_dcb.StopBits=TWOSTOPBITS; // 2
		break;

	default:; // 默认
	}

/*	switch(m_nFlowCtrl)   //流控制选项设置
	{
	case 0:
		// 硬件流控制设置
		m_dcb.fOutxCtsFlow = FALSE;
		m_dcb.fRtsControl = FALSE;
		// XON/XOFF流控制设置
		m_dcb.fInX=dcb.fOutX = FALSE;
		//m_dcb.XonChar = XON;
		//m_dcb.XoffChar = XOFF;
		////m_dcb.XonLim = 50;
		//m_dcb.XoffLim = 50;
		break;
	case 1:
		// 硬件流控制设置
		m_dcb.fOutxCtsFlow = TRUE;
		m_dcb.fRtsControl = TRUE;

		// XON/XOFF流控制设置
		m_dcb.fInX=m_dcb.fOutX = FALSE;
		//m_dcb.XonChar = XON;
		//m_dcb.XoffChar = XOFF;
		//m_dcb.XonLim = 50;
		//m_dcb.XoffLim = 50;
		break;
	case 2:
		// 软件流控制设置
		m_dcb.fOutxCtsFlow = FALSE;
		m_dcb.fRtsControl = FALSE;

		// XON/XOFF流控制设置
		m_dcb.fInX=m_dcb.fOutX = TRUE;
		m_dcb.XonChar = XON;
		m_dcb.XoffChar = XOFF;
		m_dcb.XonLim = 50;
		m_dcb.XoffLim = 50;
		break;
	default:
		break;
	}
*/
	// DCB设定
	if(!SetCommState(m_hComm, &m_dcb))
		return FALSE;

	// 把间隔超时设为最大，把总超时设为0将导致ReadFile立即返回并完成操作
	m_CommTimeouts.ReadIntervalTimeout=MAXDWORD; 
	m_CommTimeouts.ReadTotalTimeoutMultiplier=0; 
	m_CommTimeouts.ReadTotalTimeoutConstant=0; 

	/* 设置写超时以指定WriteComm成员函数中的GetOverlappedResult函数的等待时间*/
	m_CommTimeouts.WriteTotalTimeoutMultiplier=50;
	m_CommTimeouts.WriteTotalTimeoutConstant=2000;
	// 超时设定
	SetCommTimeouts(m_hComm, &m_CommTimeouts);

	SetupComm(m_hComm,MAXBLOCK,MAXBLOCK); // 缓冲区大小设定
	SetCommMask(m_hComm, EV_RXCHAR); // 通信事件设定 EV_RXCHAR：输入缓冲区收到新字符


	return TRUE;
}

//
//  The CommThread Function.
//
UINT CSerialPort::CommThread(LPVOID pParam)
{
	// Cast the void pointer passed to the thread back to
	// a pointer of CSerialPort class
	CSerialPort *port = (CSerialPort*)pParam;
	
	// Set the status variable in the dialog class to
	// TRUE to indicate the thread is running.
	port->m_bThreadAlive = TRUE;	
		
	// Misc. variables
	DWORD BytesTransfered = 0; 
	DWORD Event = 0;
	DWORD CommEvent = 0;
	DWORD dwError = 0;
	COMSTAT comstat;
	BOOL  bResult = TRUE;
		
	// Clear comm buffers at startup
	if (port->m_hComm)		// check if the port is opened
		PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);

	// begin forever loop.  This loop will run as long as the thread is alive.
	for (;;) 
	{ 

		// Make a call to WaitCommEvent().  This call will return immediatly
		// because our port was created as an async port (FILE_FLAG_OVERLAPPED
		// and an m_OverlappedStructerlapped structure specified).  This call will cause the 
		// m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to 
		// be placed in a non-signeled state if there are no bytes available to be read,
		// or to a signeled state if there are bytes available.  If this event handle 
		// is set to the non-signeled state, it will be set to signeled when a 
		// character arrives at the port.

		// we do this for each port!

		bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov);

		if (!bResult)  
		{ 
			// If WaitCommEvent() returns FALSE, process the last error to determin
			// the reason..
			switch (dwError = GetLastError()) 
			{ 
			case ERROR_IO_PENDING: 	
				{ 
					// This is a normal return value if there are no bytes
					// to read at the port.
					// Do nothing and continue
					break;
				}
			case 87:
				{