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项目做到最后了，上位机（普通台式计算机）需要接收下位机（实验板）处理过后的数据，由于返回的数据较少，一次可能就是几个字节，传输时间没有严格要求，所以选择了串口通信。串口通信方式简单。调试起来也比较简单。下位机的串口硬件调试是PK同学负责的，我负责上位机的串口程序的调试。

刚开始的调试想法是让计算机COM1口发送数据，然后COM2接收，后来发现计算机就只带有一个串口，那就用邻近同学的计算机发送数据吧，但是这样是无法通信的，因为我的串口线是对等的。后来根据小丫头同学调试串口的经验，让一个串口COM1自发自收，这样就不用考虑对等线还是交叉线的问题了。

调试计算机串口，需要一根串口线，对等线或者交叉线均可。
1、检测串口线是否能连通；检测方法，用万用表检测串口线的1-9号线是否对应连通。
2、检测计算机串口是否能正常工作；检测方法，将串口线一端接入计算机串口，另一端2、3两线用导线连通。下载串口调试助手观察计算机串口的自发自收情况。
3、检测自己程序的正确性；

以下串口类在原始是应用于WINCE下，我稍作修改即可在windows下运行。以下程序在VC2005下编译、测试通过。PSerialPort.cpp增加了TRACE调试的代码。

//From unkown author:unkonwn modified by IndexZ@xinzero.com
//PSerialPort.h
#pragma once
typedef void (*LPDataArriveProc)(char *data,int length,DWORD userdata);
class CPSerialPort
{
public:
	CPSerialPort();
	virtual ~CPSerialPort();
	BOOL OpenPort(LPCTSTR Port,int Baudrate,
		/*int DataBits,int StopBits,int Parity,*/
		LPDataArriveProc proc=NULL,DWORD userdata=0); //打开串口
	BOOL ClosePort();		//关闭串口
	//激活与关闭持续接收
	BOOL Activate();
	BOOL Deactivate();
	BOOL IsActive();
	//接收数据线程函数
	static DWORD WINAPI ReadPortThread(LPVOID lpParameter);
	DWORD ReadPort(char *data,int length);		//读取一定长度的数据
	DWORD WritePort(char *data,int length);		//发送数据
	DWORD WriteFileToPort(LPCTSTR FileName);	//发送文件
private:
	HANDLE m_hComm; //串口设备handle
	HANDLE m_hReadThread; //读串口线程handle
	BOOL m_bReceiving; //是否持续接收
	int m_nBufferSize; //缓冲大小
	char *Buffer; //缓冲区
	LPDataArriveProc m_lpDataArriveProc;
	DWORD m_dwUserData;
	//串口设置以及超时参数
	DCB dcb;
	COMMTIMEOUTS CommTimeOuts;
};

//From unkown author:unkonwn modified by IndexZ@xinzero.com
//PSerialPort.cpp
#include "StdAfx.h"
#include "PSerialPort.h" 

//////////////////////////////////////////////////////////////////////
// Construction/Destruction
////////////////////////////////////////////////////////////////////// 

CPSerialPort::CPSerialPort()
{
	m_hComm = INVALID_HANDLE_VALUE;
	m_hReadThread = NULL;
	m_bReceiving = FALSE;
	m_nBufferSize = 256; //缓冲大小
} 

CPSerialPort::~CPSerialPort()
{
	ClosePort();
} 

DWORD WINAPI CPSerialPort::ReadPortThread(LPVOID lpParameter)
{
	CPSerialPort* m_pSerial;
	m_pSerial=(CPSerialPort*)lpParameter;
	BOOL fReadState;
	DWORD dwLength;
	char* buf=new char[m_pSerial->m_nBufferSize];
	while((m_pSerial->m_hComm!=INVALID_HANDLE_VALUE)
		&&(m_pSerial->m_bReceiving))
	{
		fReadState=ReadFile(m_pSerial->m_hComm,
			buf,m_pSerial->m_nBufferSize,&dwLength,NULL);
		if(!fReadState)
		{
			AfxMessageBox(_T("无法从串口读取数据！"));
		}
		else
		{
			if(dwLength!=0)
			{	//调试输出代码开始
				TRACE("%d\n",dwLength);
				int *pint = (int*)buf;
				for(int i=0;i<(dwLength/(sizeof(int)));i++)
				{
					TRACE("%d\n",pint[i]);
				}//调试输出代码结束
				//回送数据
				if(m_pSerial->m_lpDataArriveProc!=NULL)
				{
					m_pSerial->m_lpDataArriveProc(buf,
							dwLength,m_pSerial->m_dwUserData);
				}
			}
		}
		Sleep(100);		//休眠cpu
	}
	delete[] buf;
	return 0;
} 

BOOL CPSerialPort::OpenPort(LPCTSTR Port,int BaudRate,
			/*int DataBits,int StopBits,int Parity,*/
			LPDataArriveProc proc,DWORD userdata)
{
	m_lpDataArriveProc = proc;
	m_dwUserData = userdata; 

	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		m_hComm=CreateFile(Port,GENERIC_READ|GENERIC_WRITE,0,0,OPEN_EXISTING,0,0);
		if(m_hComm==INVALID_HANDLE_VALUE )
		{
			AfxMessageBox(_T("无法打开端口！请检查是否已被占用。"));
			return FALSE;
		}
		GetCommState(m_hComm,&dcb);
		dcb.BaudRate=BaudRate;
		//dcb.ByteSize=DataBits;
		//dcb.Parity=Parity;
		//dcb.StopBits=StopBits;
		dcb.fParity=FALSE;
		dcb.fBinary=TRUE;
		dcb.fDtrControl=0;
		dcb.fRtsControl=0;
		dcb.fOutX=dcb.fInX=dcb.fTXContinueOnXoff=0; 

		//设置状态参数
		SetCommMask(m_hComm,EV_RXCHAR);
		SetupComm(m_hComm,16384,16384);
		if(!SetCommState(m_hComm,&dcb))
		{
			AfxMessageBox(_T("无法按当前参数配置端口，请检查参数！"));
			PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
			ClosePort();
			return FALSE;
		} 

		//设置超时参数
		GetCommTimeouts(m_hComm,&CommTimeOuts);
		CommTimeOuts.ReadIntervalTimeout=100;
		CommTimeOuts.ReadTotalTimeoutMultiplier=1;
		CommTimeOuts.ReadTotalTimeoutConstant=100;
		CommTimeOuts.WriteTotalTimeoutMultiplier=0;
		CommTimeOuts.WriteTotalTimeoutConstant=0;
		if(!SetCommTimeouts(m_hComm,&CommTimeOuts))
		{
			AfxMessageBox(_T("无法设置超时参数！"));
			PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
			ClosePort();
			return FALSE;
		} 

		PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
		return TRUE;
	} 

	return FALSE;
} 

BOOL CPSerialPort::ClosePort()
{
	Deactivate();
	if(m_hComm!=INVALID_HANDLE_VALUE)
	{
		SetCommMask(m_hComm,0);
		PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
		CloseHandle(m_hComm);
		m_hComm=INVALID_HANDLE_VALUE;
		return TRUE;
	} 

	return TRUE;
} 

BOOL CPSerialPort::Activate()
{
	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		return FALSE;
	} 

	if(!m_bReceiving)
	{
		//开始接收线程
		PurgeComm(m_hComm,PURGE_TXCLEAR|PURGE_RXCLEAR);
		m_bReceiving=TRUE;
		m_hReadThread=CreateThread(NULL,0,ReadPortThread,this,0,NULL);
	}
	if(m_hReadThread!=NULL)
	{
		return TRUE;
	}
	else
	{
		m_bReceiving=FALSE;
		return FALSE;
	} 

	return FALSE;
} 

BOOL CPSerialPort::Deactivate()
{
	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		return FALSE;
	} 

	//停止接收线程
	if(m_bReceiving)
	{
		m_bReceiving=FALSE;
		WaitForSingleObject(m_hReadThread,500);
		CloseHandle(m_hReadThread);
		m_hReadThread=NULL;
		return TRUE;
	} 

	return FALSE;
} 

BOOL CPSerialPort::IsActive()
{
	return m_bReceiving;
} 

DWORD CPSerialPort::WritePort(char *data,int length)
{
	if(m_hComm == INVALID_HANDLE_VALUE)
	{
		return 0;
	} 

	BOOL bFileWriteState;
	DWORD dwBytesWritten=0; 

	bFileWriteState = WriteFile(m_hComm,data,
			length*sizeof(char),&dwBytesWritten,NULL);
//	AfxMessageBox(L"正在写串口数据。。。");
	return dwBytesWritten;
} 

DWORD CPSerialPort::ReadPort(char *data,int length)
{
	BOOL bFileReadState;
	DWORD dwLength,dwByteRead;
	int TimeOutCount; 

	dwByteRead=0;
	TimeOutCount=0;
//	AfxMessageBox(L"正在读串口数据。。。");
	while(m_hComm!=INVALID_HANDLE_VALUE)
	{
		char* buf=new char[length];
		bFileReadState = ReadFile(m_hComm,data,length,&dwLength,NULL);
		if(!bFileReadState)
		{
			break;
		}
		else
		{
			dwByteRead+=dwLength;
			data+=dwLength;
		}
		if(dwByteRead == (unsigned long)length)
		{
			break;
		}
		if(dwLength!=0)
		{
			TimeOutCount=0;
		}
		else
		{
			TimeOutCount++;
			Sleep(5);
		}
		if(TimeOutCount==5)
		{
			break;
		}
	}
	return dwByteRead;
} 

DWORD CPSerialPort::WriteFileToPort(LPCTSTR FileName)
{
	CFile cf; 

	BOOL fWriteState,isOpen;
	DWORD dwBytesWritten;
	DWORD dwCharToWrite; 

	dwCharToWrite=0; 

	if(m_hComm==INVALID_HANDLE_VALUE)
	{
		return 0;
	}
	isOpen = cf.Open(FileName,CFile::modeRead);
	if(!isOpen)
	{
		//AfxMessageBox(_T("无法打开Hex文件！"));
		return 0;
	}
	dwCharToWrite=(DWORD)cf.GetLength();
	cf.Seek(0,CFile::begin); 

	dwBytesWritten=0; 

	if(m_hComm!=INVALID_HANDLE_VALUE&&dwCharToWrite!=0)
	{
		char* buf=new char[dwCharToWrite];
		cf.Read(buf,dwCharToWrite); 

		fWriteState=WriteFile(m_hComm,buf,dwCharToWrite*sizeof(char),
					&dwBytesWritten,NULL);
		if(!fWriteState)
		{
			//AfxMessageBox(_T("无法向端口写入数据！"));
		}
		delete[] buf;
	}
	cf.Close();
	return dwBytesWritten;
}