[WinAPI] 시리얼 통신 클래스 – 공부하는 개발자

Visual C++에서 사용할 수 있는 시리얼 클래스

예전 회사에 입사했을 때, 인터넷에서 긁어서 처음 만들어본 클래스입니다. 너무 오래되서 어떻게 만들었는지 모르겠습니다.
부모 윈도우 핸들을 넘겨서 메시지로 표시하는 방식입니다.

아래는 헤더 파일입니다.

#pragma once
#include "afxwin.h"
#define MAXBUF         50000 
#define InBufSize      50000
#define OutBufSize     50000
#define ASCII_XON      0x11
#define ASCII_XOFF     0x13
#define WM_MYRECEIVE   (WM_USER+1) //데이터 수신 메시지
#define WM_MYCLOSE     (WM_USER+2) // 종료 메시지

class CSerial_Comm : public CCmdTarget
{
public:
	CSerial_Comm();
	~CSerial_Comm();

public:
	HANDLE  m_hComDev;
	HWND    m_hWnd;

	BOOL    m_bIsOpenned;
	CString m_sComPort;
	CString m_sBaudRate;
	CString m_sParity;
	CString m_sDataBit;
	CString m_sStopBit;
	BOOL    m_bFlowChk;

	OVERLAPPED m_OLR, m_OLW;
	char    m_sInBuf[MAXBUF * 2];
	int            m_nLength;
	CEvent* m_pEvent;

public:
	void Clear();
	int Receive(LPSTR inbuf, int len);
	BOOL Send(LPCTSTR outbuf, int len);
	BOOL Create(HWND hWnd);
	void HandleClose();
	void Close();
	void ResetSerial();
	CSerial_Comm(CString port, CString baudrate, CString parity, CString databit, CString stopbit);

};

아래는 cpp 파일 입니다.

#include "stdafx.h"
#include "Serial_Comm.h"


CSerial_Comm::CSerial_Comm()
{
	if (m_bIsOpenned)
		Close();
	delete m_pEvent;

}

CSerial_Comm::CSerial_Comm(CString port, CString baudrate, CString parity, CString databit, CString stopbit)
{
	m_sComPort = port;
	m_sBaudRate = baudrate;
	m_sParity = parity;
	m_sDataBit = databit;
	m_sStopBit = stopbit;
	m_bFlowChk = 1;
	m_bIsOpenned = FALSE;
	m_nLength = 0;
	memset(m_sInBuf, 0, MAXBUF * 2);
	m_pEvent = new CEvent(FALSE, TRUE);
}

void CSerial_Comm::ResetSerial()
{
	DCB                              dcb;
	DWORD      DErr;
	COMMTIMEOUTS           CommTimeOuts;

	if (!m_bIsOpenned)
		return;

	ClearCommError(m_hComDev, &DErr, NULL);
	SetupComm(m_hComDev, InBufSize, OutBufSize);
	PurgeComm(m_hComDev, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);

	// set up for overlapped I/O
	CommTimeOuts.ReadIntervalTimeout = MAXDWORD;
	CommTimeOuts.ReadTotalTimeoutMultiplier = 0;
	CommTimeOuts.ReadTotalTimeoutConstant = 0;

	// CBR_9600 is approximately 1byte/ms. For our purposes, allow
	// double the expected time per character for a fudge factor.
	CommTimeOuts.WriteTotalTimeoutMultiplier = 0;
	CommTimeOuts.WriteTotalTimeoutConstant = 1000;
	SetCommTimeouts(m_hComDev, &CommTimeOuts);


	memset(&dcb, 0, sizeof(DCB));
	dcb.DCBlength = sizeof(DCB);

	GetCommState(m_hComDev, &dcb);

	dcb.fBinary = TRUE;
	dcb.fParity = TRUE;

	if (m_sBaudRate == "300")
		dcb.BaudRate = CBR_300;
	else if (m_sBaudRate == "600")
		dcb.BaudRate = CBR_600;
	else if (m_sBaudRate == "1200")
		dcb.BaudRate = CBR_1200;
	else if (m_sBaudRate == "2400")
		dcb.BaudRate = CBR_2400;
	else if (m_sBaudRate == "4800")
		dcb.BaudRate = CBR_4800;
	else if (m_sBaudRate == "9600")
		dcb.BaudRate = CBR_9600;
	else if (m_sBaudRate == "14400")
		dcb.BaudRate = CBR_14400;
	else if (m_sBaudRate == "19200")
		dcb.BaudRate = CBR_19200;
	else if (m_sBaudRate == "28800")
		dcb.BaudRate = CBR_38400;
	else if (m_sBaudRate == "33600")
		dcb.BaudRate = CBR_38400;
	else if (m_sBaudRate == "38400")
		dcb.BaudRate = CBR_38400;
	else if (m_sBaudRate == "56000")
		dcb.BaudRate = CBR_56000;
	else if (m_sBaudRate == "57600")
		dcb.BaudRate = CBR_57600;
	else if (m_sBaudRate == "115200")
		dcb.BaudRate = CBR_115200;
	else if (m_sBaudRate == "128000")
		dcb.BaudRate = CBR_128000;
	else if (m_sBaudRate == "256000")
		dcb.BaudRate = CBR_256000;
	else if (m_sBaudRate == "PCI_9600")
		dcb.BaudRate = 1075;
	else if (m_sBaudRate == "PCI_19200")
		dcb.BaudRate = 2212;
	else if (m_sBaudRate == "PCI_38400")
		dcb.BaudRate = 4300;
	else if (m_sBaudRate == "PCI_57600")
		dcb.BaudRate = 6450;
	else if (m_sBaudRate == "PCI_500K")
		dcb.BaudRate = 56000;


	if (m_sParity == "None")
		dcb.Parity = NOPARITY;
	else if (m_sParity == "Even")
		dcb.Parity = EVENPARITY;
	else if (m_sParity == "Odd")
		dcb.Parity = ODDPARITY;

	if (m_sDataBit == "7 Bit")
		dcb.ByteSize = 7;
	else if (m_sDataBit == "8 Bit")
		dcb.ByteSize = 8;

	if (m_sStopBit == "1 Bit")
		dcb.StopBits = ONESTOPBIT;
	else if (m_sStopBit == "1.5 Bit")
		dcb.StopBits = ONE5STOPBITS;
	else if (m_sStopBit == "2 Bit")
		dcb.StopBits = TWOSTOPBITS;

	dcb.fRtsControl = RTS_CONTROL_ENABLE;
	dcb.fDtrControl = DTR_CONTROL_ENABLE;
	dcb.fOutxDsrFlow = FALSE;

	if (m_bFlowChk) {
		dcb.fOutX = FALSE;
		dcb.fInX = FALSE;
		dcb.XonLim = 2048;
		dcb.XoffLim = 1024;
	}
	else {
		dcb.fOutxCtsFlow = TRUE;
		dcb.fRtsControl = RTS_CONTROL_HANDSHAKE;
	}

	SetCommState(m_hComDev, &dcb);
	SetCommMask(m_hComDev, EV_RXCHAR);

}

void CSerial_Comm::Close()
{
	if (!m_bIsOpenned)
		return;

	m_bIsOpenned = FALSE;
	SetCommMask(m_hComDev, 0);
	EscapeCommFunction(m_hComDev, CLRDTR);
	PurgeComm(m_hComDev, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);
	Sleep(500);
}


UINT CommThread(LPVOID lpData)
{
	extern short g_nRemoteStatus;
	DWORD       ErrorFlags;
	COMSTAT     ComStat;
	DWORD      EvtMask;
	char            buf[MAXBUF];
	DWORD      Length;
	int              size;
	int              insize = 0;

	CSerial_Comm* Comm = (CSerial_Comm*)lpData;

	while (Comm->m_bIsOpenned)
	{
		EvtMask = 0;
		Length = 0;
		insize = 0;
		memset(buf, '\0', MAXBUF);


		// 포트에 수신된 정보가 있을때까지 대기
		WaitCommEvent(Comm->m_hComDev, &EvtMask, NULL);

		ClearCommError(Comm->m_hComDev, &ErrorFlags, &ComStat);
		if ((EvtMask & EV_RXCHAR) && ComStat.cbInQue)
		{
			if (ComStat.cbInQue > MAXBUF)
				size = MAXBUF;
			else
				size = ComStat.cbInQue;
			do
			{
				ClearCommError(Comm->m_hComDev, &ErrorFlags, &ComStat);
				if (!ReadFile(Comm->m_hComDev, buf + insize, size, &Length, &(Comm->m_OLR)))
				{
					// 에러
					TRACE("Error in ReadFile\n");
					if (GetLastError() == ERROR_IO_PENDING)
					{
						if (WaitForSingleObject(Comm->m_OLR.hEvent, 1000) != WAIT_OBJECT_0)
							Length = 0;
						else
							GetOverlappedResult(Comm->m_hComDev, &(Comm->m_OLR), &Length, FALSE);
					}
					else
						Length = 0;
				}
				insize += Length;
			} while ((Length != 0) && (insize<size));
			ClearCommError(Comm->m_hComDev, &ErrorFlags, &ComStat);

			if (Comm->m_nLength + insize > MAXBUF * 2)
				insize = (Comm->m_nLength + insize) - MAXBUF * 2;

			Comm->m_pEvent->ResetEvent();
			memcpy(Comm->m_sInBuf + Comm->m_nLength, buf, insize);
			Comm->m_nLength += insize;
			Comm->m_pEvent->SetEvent();
			LPARAM temp = (LPARAM)Comm;

			SendMessage(Comm->m_hWnd, WM_MYRECEIVE, Comm->m_nLength, temp);
		}
	}
	PurgeComm(Comm->m_hComDev, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);
	LPARAM temp = (LPARAM)Comm;
	SendMessage(Comm->m_hWnd, WM_MYCLOSE, 0, temp);
	return 0;
}

void CSerial_Comm::HandleClose()
{
	CloseHandle(m_hComDev);
	CloseHandle(m_OLR.hEvent);
	CloseHandle(m_OLW.hEvent);

}

BOOL CSerial_Comm::Create(HWND hWnd)
{
	m_hWnd = hWnd;

	m_hComDev = CreateFile(m_sComPort, GENERIC_READ | GENERIC_WRITE,
		0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL | FILE_FLAG_OVERLAPPED,
		NULL);

	if (m_hComDev != INVALID_HANDLE_VALUE)
		m_bIsOpenned = TRUE;
	else
		return FALSE;

	ResetSerial();

	m_OLW.Offset = 0;
	m_OLW.OffsetHigh = 0;
	m_OLR.Offset = 0;
	m_OLR.OffsetHigh = 0;

	m_OLR.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
	if (m_OLR.hEvent == NULL) {
		CloseHandle(m_OLR.hEvent);
		return FALSE;
	}
	m_OLW.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
	if (m_OLW.hEvent == NULL) {
		CloseHandle(m_OLW.hEvent);
		return FALSE;
	}
	AfxBeginThread(CommThread, (LPVOID)this);
	EscapeCommFunction(m_hComDev, SETDTR);
	return TRUE;

}

BOOL CSerial_Comm::Send(LPCTSTR outbuf, int len)
{
	BOOL          bRet = TRUE;
	DWORD       ErrorFlags;
	COMSTAT     ComStat;

	DWORD       BytesWritten;
	DWORD       BytesSent = 0;

	ClearCommError(m_hComDev, &ErrorFlags, &ComStat);
	if (!WriteFile(m_hComDev, outbuf, len, &BytesWritten, &m_OLW))
	{
		if (GetLastError() == ERROR_IO_PENDING)
		{
			if (WaitForSingleObject(m_OLW.hEvent, 1000) != WAIT_OBJECT_0)
				bRet = FALSE;
			else
				GetOverlappedResult(m_hComDev, &m_OLW, &BytesWritten, FALSE);
		}
		else /* I/O error */
			bRet = FALSE; /* ignore error */
	}

	ClearCommError(m_hComDev, &ErrorFlags, &ComStat);

	return bRet;
}


int CSerial_Comm::Receive(LPSTR inbuf, int len)
{
	CSingleLock lockObj((CSyncObject*)m_pEvent, FALSE);
	// argument value is not valid
	if (len == 0)
		return -1;
	else if (len > MAXBUF)
		return -1;

	if (m_nLength == 0)
	{
		inbuf[0] = '\0';
		return 0;
	}
	else if (m_nLength <= len)
	{
		lockObj.Lock();
		memcpy(inbuf, m_sInBuf, m_nLength);
		memset(m_sInBuf, 0, MAXBUF * 2);
		int tmp = m_nLength;
		m_nLength = 0;
		lockObj.Unlock();
		return tmp;
	}
	else
	{
		lockObj.Lock();
		memcpy(inbuf, m_sInBuf, len);
		memmove(m_sInBuf, m_sInBuf + len, MAXBUF * 2 - len);
		m_nLength -= len;
		lockObj.Unlock();
		return len;
	}
}

void CSerial_Comm::Clear()
{
	PurgeComm(m_hComDev, PURGE_TXABORT | PURGE_RXABORT | PURGE_TXCLEAR | PURGE_RXCLEAR);
	memset(m_sInBuf, 0, MAXBUF * 2);
	m_nLength = 0;
}

CSerial_Comm::~CSerial_Comm()
{
}

옛날 소스라 stdafx.h가 포함되어 있네요. 2019에서는 pch.h로 하셔야 할겁니다.

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