serialport.cpp

串行通讯程序,为电池分析仪与电脑通讯软件,效果不错.

				// Write character event from port
				WriteChar(port);
				break;
			}

		} // end switch

	} // close forever loop

	return 0;
}

//
// start comm watching
//
BOOL CSerialPort::StartMonitoring()
{
	if (!(m_Thread = AfxBeginThread(CommThread, this)))
		return FALSE;
	TRACE("Thread started\n");
	return TRUE;	
}

//
// Restart the comm thread
//
BOOL CSerialPort::RestartMonitoring()
{
	TRACE("Thread resumed\n");
	m_Thread->ResumeThread();
	return TRUE;	
}


//
// Suspend the comm thread
//
BOOL CSerialPort::StopMonitoring()
{
	TRACE("Thread suspended\n");
	m_Thread->SuspendThread(); 
	return TRUE;	
}


//
// If there is a error, give the right message
//
void CSerialPort::ProcessErrorMessage(char* ErrorText)
{
	char *Temp = new char[200];
	
	LPVOID lpMsgBuf;

	FormatMessage( 
		FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM,
		NULL,
		GetLastError(),
		MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
		(LPTSTR) &lpMsgBuf,
		0,
		NULL 
	);

//	sprintf(Temp, "WARNING:  %s Failed with the following error: \n%s\nPort: %d\n", (char*)ErrorText, lpMsgBuf, m_nPortNr); 
	MessageBox(NULL, Temp, "Application Error", MB_ICONSTOP);

	LocalFree(lpMsgBuf);
	delete[] Temp;
}

//
// Write a character.
//
void CSerialPort::WriteChar(CSerialPort* port)
{
	BOOL bWrite = TRUE;
	BOOL bResult = TRUE;

	DWORD BytesSent = 0;

	ResetEvent(port->m_hWriteEvent);

	// Gain ownership of the critical section
	EnterCriticalSection(&port->m_csCommunicationSync);

	if (bWrite)
	{
		// Initailize variables
		port->m_ov.Offset = 0;
		port->m_ov.OffsetHigh = 0;
		// Clear buffer
		PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);

		bResult = WriteFile(port->m_hComm,							// Handle to COMM Port
							port->m_sTxt,					// Pointer to message buffer in calling finction
							port->nNumByteWrite,	// Length of message to send
							&BytesSent,								// Where to store the number of bytes sent
							&port->m_ov);							// Overlapped structure

		// deal with any error codes  LPCVOID
		if (!bResult)  
		{
			DWORD dwError = GetLastError();
			switch (dwError)
			{
				case ERROR_IO_PENDING:
					{
						// continue to GetOverlappedResults()
						BytesSent = 0;
						bWrite = FALSE;
						break;
					}
				default:
					{
						// all other error codes
						port->ProcessErrorMessage("WriteFile()");
					}
			}
		} 
		else
		{
			LeaveCriticalSection(&port->m_csCommunicationSync);
		}
	} // end if(bWrite)

	if (!bWrite)
	{
		bWrite = TRUE;
	
		bResult = GetOverlappedResult(port->m_hComm,	// Handle to COMM port 
									  &port->m_ov,		// Overlapped structure
									  &BytesSent,		// Stores number of bytes sent
									  TRUE); 			// Wait flag

		LeaveCriticalSection(&port->m_csCommunicationSync);

		// deal with the error code 
		if (!bResult)  
		{
			port->ProcessErrorMessage("GetOverlappedResults() in WriteFile()");
		}	
	} // end if (!bWrite)

	// Verify that the data size send equals what we tried to send
	if (BytesSent != port->nNumByteWrite)
	{
		TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent, strlen((char*)port->m_sTxt));
	}
}

//
// Character received. Inform the owner
//
void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat)
{
	BOOL  bRead = TRUE; 
	BOOL  bResult = TRUE;
	DWORD dwError = 0;
	DWORD BytesRead = 0;
    int RXNumber=256;

	for (;;) 
	{ 
		// Gain ownership of the comm port critical section.
		// This process guarantees no other part of this program 
		// is using the port object. 
		
		EnterCriticalSection(&port->m_csCommunicationSync);

		// ClearCommError() will update the COMSTAT structure and
		// clear any other errors.
		
		bResult = ClearCommError(port->m_hComm, &dwError, &comstat);

		LeaveCriticalSection(&port->m_csCommunicationSync);

		// start forever loop.  I use this type of loop because I
		// do not know at runtime how many loops this will have to
		// run. My solution is to start a forever loop and to
		// break out of it when I have processed all of the
		// data available.  Be careful with this approach and
		// be sure your loop will exit.
		// My reasons for this are not as clear in this sample 
		// as it is in my production code, but I have found this 
		// solutiion to be the most efficient way to do this.
		
		if (comstat.cbInQue == 0)
		{
			// break out when all bytes have been read
			break;
		}
				
		EnterCriticalSection(&port->m_csCommunicationSync);

		if (bRead)
		{
			bResult = ReadFile(port->m_hComm,		// Handle to COMM port 
							   port->m_strRXData,				// RX Buffer Pointer
							   RXNumber,					// Read one byte
							   &BytesRead,			// Stores number of bytes read
							   &port->m_ov);		// pointer to the m_ov structure
			// deal with the error code 
			if (!bResult)  
			{ 
				switch (dwError = GetLastError()) 
				{ 
					case ERROR_IO_PENDING: 	
						{ 
							// asynchronous i/o is still in progress 
							// Proceed on to GetOverlappedResults();
							bRead = FALSE;
							break;
						}
					default:
						{
							// Another error has occured.  Process this error.
							port->ProcessErrorMessage("ReadFile()");
							break;
						} 
				}
			}
			else
			{
				// ReadFile() returned complete. It is not necessary to call GetOverlappedResults()
				bRead = TRUE;
			}
		}  // close if (bRead)

		if (!bRead)
		{
			bRead = TRUE;
			bResult = GetOverlappedResult(port->m_hComm,	// Handle to COMM port 
										  &port->m_ov,		// Overlapped structure
										  &BytesRead,		// Stores number of bytes read
										  TRUE); 			// Wait flag

			// deal with the error code 
			if (!bResult)  
			{
				port->ProcessErrorMessage("GetOverlappedResults() in ReadFile()");
			}	
		}  // close if (!bRead)
				
		LeaveCriticalSection(&port->m_csCommunicationSync);
		port->nNumByteRead=BytesRead;
		// notify parent that a byte was received
		::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_RXCHAR, (WPARAM) 0, (LPARAM) BytesRead);
	} // end forever loop

}

//
// Write a string to the port
//


//
// Return the device control block
//


//
// Return the communication event masks
//
DWORD CSerialPort::GetCommEvents()
{
	return m_dwCommEvents;
}

//
// Return the output buffer size
//






int CSerialPort::WriteToDevice(char cmd,char the_station,char setup,char * bs,int len) 
{ 	assert(m_hComm != 0);
  char Chechsum=0;
	unsigned char  n=0;
//char tmp[30];
	assert(m_hComm != 0);
	memset(m_sTxt, 0, 256);
    m_sTxt[n++]=(char)cmd;
    Chechsum+=cmd;
	if (the_station)
	{
    m_sTxt[n++]=the_station; 
    Chechsum+=the_station; 
	}
	if (setup)
    {
    m_sTxt[n++]=setup; 
    Chechsum+= setup;
	}

	for(int i=0;i<len;i++)
 	Chechsum+= m_sTxt[n++]=bs[i];
	Chechsum=~Chechsum&0x7F;
    m_sTxt[n++]=Chechsum;

    m_sTxt[n++]=(char)0x80;
	nNumByteWrite=n;
	// set event for write
	SetEvent(m_hWriteEvent);
	// set event for write

//	SetEvent(m_hWriteEvent);
  return 0;
}



void CSerialPort::StopComm()
{
	do
	{
		SetEvent(m_hShutdownEvent);
	} while (m_bThreadAlive);

	TRACE("Thread ended\n");
}