일반적인 시리얼포트 제어 방법은..

 

1. 포트를 생성하고..

HANDLE  hPort = CreateFile (lpszPortName,

                      GENERIC_WRITE,
                      0,

                      NULL,
                      OPEN_EXISTING,
                      0, 

                      NULL); 

 

2. 포트를 설정하고..

DCB PortDCB;

PortDCB.DCBlength = sizeof (DCB);

GetCommState (hPort, &PortDCB);

PortDCB.BaudRate = 9600;

PortDCB.fBinary = TRUE;
PortDCB.fParity = TRUE; 
PortDCB.fOutxCtsFlow = FALSE; 
PortDCB.fOutxDsrFlow = FALSE; 
PortDCB.fDtrControl = DTR_CONTROL_ENABLE;
PortDCB.fDsrSensitivity = FALSE;
PortDCB.fTXContinueOnXoff = TRUE;
PortDCB.fOutX = FALSE;               
PortDCB.fInX = FALSE;                
PortDCB.fErrorChar = FALSE;  
PortDCB.fNull = FALSE;            
PortDCB.fRtsControl = RTS_CONTROL_ENABLE;
PortDCB.fAbortOnError = FALSE;
PortDCB.ByteSize = 8;                
PortDCB.Parity = NOPARITY;   
PortDCB.StopBits = ONESTOPBIT;

 

if (!SetCommState (hPort, &PortDCB))
{
  dwError = GetLastError ();
  MessageBox (hMainWnd, TEXT("Unable to configure the serial port"),
              TEXT("Error"), MB_OK);
  return FALSE;
}

3. 타임아웃 설정하고..

COMMTIMEOUTS CommTimeouts;
GetCommTimeouts (hPort, &CommTimeouts);

CommTimeouts.ReadIntervalTimeout = MAXDWORD; 
CommTimeouts.ReadTotalTimeoutMultiplier = 0; 
CommTimeouts.ReadTotalTimeoutConstant = 0;   
CommTimeouts.WriteTotalTimeoutMultiplier = 10; 
CommTimeouts.WriteTotalTimeoutConstant = 1000;   

 

if (!SetCommTimeouts (hPort, &CommTimeouts))
{
  // Could not set the timeout parameters.
  MessageBox (hMainWnd, TEXT("Unable to set the timeout parameters"),
              TEXT("Error"), MB_OK);
  dwError = GetLastError ();
  return FALSE;
}

4. 포트에 제어 문자 출력

DWORD dwError,
      dwNumBytesWritten;

WriteFile (hPort,     &Byte,    1,    &dwNumBytesWritten,    NULL );

5. 포트 닫으면 끝

CloseHandle(hPort);