Nochmal Winapi und RS232

// Handel fuer den comport

DCB           dcb;

DWORD         iBytesWritten, dwRead = 0;

DWORD         dwEvtMask, dwSetMask = EV_RXCHAR | EV_ERR;

HANDLE        hCom;

BOOL          bRet = TRUE;

OVERLAPPED    o;

COMMTIMEOUTS  ct;

#define RECVBYTES       5      // max. recv. bytes per transmission

#define STX             0x02

#define ETX             0x03

#define Pointer         0x00   // ?? Pointer sind 4 Byte lang?

#define CHK             0x3E

#define ENQ             0x05

/**

 * Diese Funktion initialisiert die RS232 Schnittstelle

 * und ließt / schreibt in die Buffer

 *

 *

 */

DWORD WINAPI rs232_listener(LPVOID lpParam){

    char          flag[] = {ENQ};

    unsigned char          output[] = {STX, 0x0E, Pointer, '1', ETX, CHK};

    int           laenge = sizeof(output);

    char          *Buf;

    Buf = (char*)malloc(laenge * 5 + 1);

    memset(&o, 0, sizeof(OVERLAPPED));

    o.hEvent = CreateEvent(NULL, FALSE, FALSE, NULL);

    if(!(hCom = CreateFile("COM3", GENERIC_WRITE | GENERIC_READ, 0, NULL,

                          OPEN_EXISTING, 0, NULL)))

    {

      LPVOID lpMsgBuf;

      FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |

                      FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(),

                      MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL);

      MessageBox(NULL, (LPCTSTR)lpMsgBuf, "Error: CreateFile", MB_OK | MB_ICONINFORMATION);

      LocalFree(lpMsgBuf);

    return 0; // no action

    }

    dcb.DCBlength = sizeof(DCB);

    GetCommState(hCom, &dcb);

    dcb.BaudRate  = 9600;

    dcb.ByteSize  = 8;

    dcb.Parity    = NOPARITY;

    dcb.StopBits  = TWOSTOPBITS;

    SetCommState(hCom, &dcb);

    GetCommTimeouts(hCom, &ct);

    //ct.ReadIntervalTimeout         = 50;

    ct.ReadIntervalTimeout         = 100000 / 9600 * (dcb.ByteSize +

                                                   (dcb.Parity == NOPARITY ? 0 : 1) +

                                                   (dcb.StopBits == ONESTOPBIT ? 1 : 2)) * RECVBYTES;

    ct.ReadTotalTimeoutMultiplier  = 0;

    ct.ReadTotalTimeoutConstant    = 50;

    ct.WriteTotalTimeoutMultiplier = 0;

    ct.WriteTotalTimeoutConstant   = 0;

    SetCommTimeouts(hCom, &ct);

    SetupComm(hCom, COM_BUFFER_SIZE, COM_BUFFER_SIZE);

    SetCommMask(hCom, dwSetMask);

    if(!WriteFile(hCom, &flag, 1, &iBytesWritten, NULL)){

      LPVOID lpMsgBuf;

      FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |

                    FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(),

                    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL);

      MessageBox(NULL, (LPCTSTR)lpMsgBuf, "Error: WriteFile", MB_OK | MB_ICONINFORMATION);

      LocalFree(lpMsgBuf);

    }

    return 0;

}

/**

 * Diese Funktion sendet ein Zeichen über den Sendebuffer

 */

void send_RS232(char *data, int length){

     OVERLAPPED osWrite = {0};

     DWORD dwWritten;

     DWORD dwRes;

     BOOL fRes;

     // Create this write operation's OVERLAPPED structure's hEvent.

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

     if (osWrite.hEvent == NULL)

        // error creating overlapped event handle

        printf("error\r\n");

     //printf("wait for signal");

     // Issue write.

     if (!WriteFile(hCom, data, length, &dwWritten, &osWrite)) {

        if (GetLastError() != ERROR_IO_PENDING) {

           // WriteFile failed, but isn't delayed. Report error and abort.

           fRes = FALSE;

        }else{

           // Write is pending.

           dwRes = WaitForSingleObject(osWrite.hEvent, INFINITE);

           switch(dwRes)

           {

              // OVERLAPPED structure's event has been signaled.

              case WAIT_OBJECT_0:

                   if (!GetOverlappedResult(hCom, &osWrite, &dwWritten, FALSE)){

               printf("Fehler 1");

                 fRes = FALSE;

                   }else{

                    // Write operation completed successfully.

                     printf("Ok");

                    fRes = TRUE;

                   }

                   break;

              default:

                   // An error has occurred in WaitForSingleObject.

                   // This usually indicates a problem with the

                  // OVERLAPPED structure's event handle.

                printf("Fehler 1");

                   fRes = FALSE;

                   break;

           }

        }

     }else{

        // WriteFile completed immediately.

        fRes = TRUE;

        //printf("Fehler");

     }

     CloseHandle(osWrite.hEvent);

     return;

}

/**

 * Diese Funktion empfaengt ein zeichen ueber den RS232 Buffer

 */

char receive_rs232(){

  char ret = 0;

  char InString[COM_BUFFER_SIZE + 1];

    WaitCommEvent(hCom, &dwEvtMask, &o);

    if(WAIT_OBJECT_0 == WaitForSingleObject(o.hEvent, INFINITE)) //warten bis Event

    {

      if(dwEvtMask & EV_RXCHAR)

      {

        bRet = ReadFile(hCom, &InString, sizeof(InString), &dwRead, NULL);

        if(!bRet){

          LPVOID lpMsgBuf;

          FormatMessage(FORMAT_MESSAGE_ALLOCATE_BUFFER | FORMAT_MESSAGE_FROM_SYSTEM |

                        FORMAT_MESSAGE_IGNORE_INSERTS, NULL, GetLastError(),

                        MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), (LPTSTR) &lpMsgBuf, 0, NULL);

          MessageBox(NULL, (LPCTSTR)lpMsgBuf, "Error: ReadFile", MB_OK | MB_ICONINFORMATION);

          LocalFree(lpMsgBuf);

        }

        else

        {

          InString[dwRead] = '\0';

          // Add to buffer

          rxBuffer.buffer[(rxBuffer.iWrite++)%BUFFERSIZE] = InString[0];

          rxBuffer.anzElemente = rxBuffer.anzElemente + 1;

          //printf(TEXT("%s"), InString);

        }

      }

      if(dwEvtMask & EV_ERR)

      {

        MessageBox(NULL, "Error empfangen", "Error: ReadFile", MB_OK);

      }

    }

  return ret;

}