Serial Comm Programming

See more:

C++

Hello,

I am porting an app originally written in c, to c++, and I am having difficulty converting a CString to a pointer to a character array. Please pardon all the commented out code, but I have been trying anything and everything to get this to work.

In the original app I used code from this website, with success. I am confused about if I need to use overlapped or non-overlapped. The overlapped code came from the msdn website.

When I try to use the overlapped code, I receive my data back with zero interspersed every other byte in the reply, which I expect since I am using a CString to contain the message.

I am using a loop-back connector to test the communication.

Thanks in advance.

bool ELMCommWrite(CString strDataToWrite, HANDLE hWnd)
{
	OVERLAPPED	osWrite = {0};
	DWORD		dwWritten, dwRes, dwToWrite;
	BOOL		fRes;
	char		* chDataToWrite[] = {"1234\0"};

	LPCTSTR		pstrDataToWrite = strDataToWrite;

	dwToWrite = 5;//strWriteData.StringLength();


	//osWrite.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
	//if (osWrite.hEvent == NULL)
	//	return FALSE;

	//if (!WriteFile(hCom, pstrDataToWrite, lstrlen(pstrDataToWrite) * sizeof(TCHAR), &dwWritten, &osWrite))
	WriteFile(hCom, pstrDataToWrite, lstrlen(pstrDataToWrite) * sizeof(TCHAR), &dwWritten, NULL);
	/*{
		if (GetLastError() != ERROR_IO_PENDING)
		{
			err = GetLastError();
			fRes = FALSE;
		}
		else
			dwRes = WaitForSingleObject(osWrite.hEvent , INFINITE);
		switch(dwRes)
		{
		case WAIT_OBJECT_0:
			if (!GetOverlappedResult(hCom, &osWrite, &dwWritten, FALSE))
				fRes = FALSE;
			else
				fRes = TRUE;
			break;
		default:
			fRes = FALSE;
			break;
		}
	}
	else
		fRes = TRUE;
	//CString strReply = ELMCommRead(hCom);
	ELMCommRead(hCom);
	//CloseHandle(osWrite.hEvent);
	return fRes;
	*/
	return 0;
}