main.cpp

《Visual C++串口通信开发入门与编程实践》（源码） 本书着重介绍计算机串口通信的硬件原理、软件开发和工程实例。案例式教学

//	Listener.cpp - Sample application for CSerial
//
//	Copyright (C) 1999-2003 Ramon de Klein ([e-mail])
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

#define STRICT
#include <tchar.h>
#include <windows.h>
#include <stdio.h>
#include <string.h>
#include <Serial.h>

int ShowError (LONG lError, LPCTSTR lptszMessage)
{
	// Generate a message text
	TCHAR tszMessage[256];
	wsprintf(tszMessage,_T("%s\n(error code %d)"), lptszMessage, lError);

	// Display message-box and return with an error-code
	::MessageBox(0,tszMessage,_T("Listener"), MB_ICONSTOP|MB_OK);
	return 1;
}

int __cdecl _tmain (int /*argc*/, char** /*argv*/)
{
	CSerial serial;
	LONG    lLastError = ERROR_SUCCESS;

	// Attempt to open the serial port (COM1)
	lLastError = serial.Open(_T("COM1"),0,0,true);
	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(), 
				_T("Unable to open COM-port"));

	// Setup the serial port (9600,8N1, which is the default setting)
	lLastError = serial.Setup(
				CSerial::EBaud9600,
				CSerial::EData8,
				CSerial::EParNone,
				CSerial::EStop1);

	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(), 
				_T("Unable to set COM-port setting"));

	// Register only for the receive event
	lLastError = serial.SetMask(CSerial::EEventBreak |
		CSerial::EEventCTS   |
		CSerial::EEventDSR   |
		CSerial::EEventError |
		CSerial::EEventRing  |
		CSerial::EEventRLSD  |
		CSerial::EEventRecv);
	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(),
				_T("Unable to set COM-port event mask"));

	// Use 'non-blocking' reads, because we don't know how many bytes
	// will be received. This is normally the most convenient mode
	// (and also the default mode for reading data).
	lLastError = serial.SetupReadTimeouts(CSerial::EReadTimeoutNonblocking);
	if (lLastError != ERROR_SUCCESS)
		return ::ShowError(serial.GetLastError(), 
			_T("Unable to set COM-port read timeout."));

	// Create a handle for the overlapped operations
	HANDLE hevtOverlapped = ::CreateEvent(0,TRUE,FALSE,0);;
	if (hevtOverlapped == 0)
		return ::ShowError(serial.GetLastError(),
				_T("Unable to create manual-reset event for overlapped I/O."));

	// Setup the overlapped structure
	OVERLAPPED ov = {0};
	ov.hEvent = hevtOverlapped;

	// Keep reading data, until an CRLF has been received
	bool fContinue = true;
	do
	{
		// Wait for an event
		lLastError = serial.WaitEvent(&ov);
		if (lLastError != ERROR_SUCCESS)
			return ::ShowError(serial.GetLastError(), 
				_T("Unable to wait for a COM-port event."));
		printf("Wait event started.\n");

		// Wait until something happens
		switch (::WaitForSingleObject(hevtOverlapped,INFINITE))
		{
		case WAIT_OBJECT_0:
			{
				// Save event
				const CSerial::EEvent eEvent = serial.GetEventType();

				// Handle break event
				if (eEvent & CSerial::EEventBreak)
				{
					printf("\n### BREAK received ###\n");
				}

				// Handle CTS event
				if (eEvent & CSerial::EEventCTS)
				{
					printf("\n### Clear to send %s ###\n",
						serial.GetCTS()?"on":"off");
				}

				// Handle DSR event
				if (eEvent & CSerial::EEventDSR)
				{
					printf("\n### Data set ready %s ###\n",
						serial.GetDSR()?"on":"off");
				}

				// Handle error event
				if (eEvent & CSerial::EEventError)
				{
					printf("\n### ERROR: ");
					switch (serial.GetError())
					{
					case CSerial::EErrorBreak:
						printf("Break condition");
						break;
					case CSerial::EErrorFrame:
						printf("Framing error");
						break;
					case CSerial::EErrorIOE:
						printf("IO device error");
						break;
					case CSerial::EErrorMode:
						printf("Unsupported mode");	
						break;
					case CSerial::EErrorOverrun:
						printf("Buffer overrun");
						break;
					case CSerial::EErrorRxOver:
						printf("Input buffer overflow");
						break;
					case CSerial::EErrorParity:
						printf("Input parity error");
						break;
					case CSerial::EErrorTxFull:
						printf("Output buffer full");
						break;
					default:
						printf("Unknown");
						break;
					}
					printf(" ###\n");
				}

				// Handle ring event
				if (eEvent & CSerial::EEventRing)
				{
					printf("\n### RING ###\n");
				}

				// Handle RLSD/CD event
				if (eEvent & CSerial::EEventRLSD)
				{
					printf("\n### RLSD/CD %s ###\n", serial.GetRLSD()?"on":"off");
				}

				// Handle data receive event
				if (eEvent & CSerial::EEventRecv)
				{
					// Read data, until there is nothing left
					DWORD dwBytesRead = 0;
					do
					{
						char szBuffer[101];

						// Read data from the COM-port
						lLastError = serial.Read(szBuffer,sizeof(szBuffer)-1,&dwBytesRead);
						if (lLastError != ERROR_SUCCESS)
							return ::ShowError(serial.GetLastError(), _T("Unable to read from COM-port."));

						if (dwBytesRead > 0)
						{
							// Finalize the data, so it is a valid string
							szBuffer[dwBytesRead] = '\0';

							// Display the data
							printf("%s", szBuffer);

							if (strchr(szBuffer,'\n'))
								fContinue = false;
						}
					}
					while (dwBytesRead > 0);
				}
			}
			break;

		case WAIT_ABANDONED:
			{
				// Set the continue bit to false, so we'll exit
				fContinue = false;
			}
			break;

		default:
			{
				// Something went wrong
				return ::ShowError(serial.GetLastError(), _T("Error while calling WaitForMultipleObjects."));
			}
			break;
		}
	}
	while (fContinue);

	// Close the port again
	serial.Close();
	return 0;
}