mit C den COM Port ansprechen

[maddin]

moin leutz,

ich habe da ein kleines problem. und zwar habe ich da ein kleines programm, welches den eine serielle schnittstelle ansprechen soll. problem: wie spricht man die serielle schnittstelle an.

------------------

mfg maddin

[X_22]

Ich hab auf einer Englischen Seite was dazu gesehen. Ist aber in VC++

/*

** FILENAME CSerialPort.h

**

** PURPOSE This class can read, write and watch one serial port.

** It sends messages to its owner when something happends on the port

** The class creates a thread for reading and writing so the main

** program is not blocked.

**

** CREATION DATE 15-09-1997

** LAST MODIFICATION 24-11-1998

**

** AUTHOR Remon Spekreijse

** MODIFIED BY Brian Koh Sze Hsian

**

*/

#ifndef __SERIALPORT_H__

#define __SERIALPORT_H__

#define WM_COMM_BREAK_DETECTED WM_USER+1 // A break was detected on input.

#define WM_COMM_CTS_DETECTED WM_USER+2 // The CTS (clear-to-send) signal changed state.

#define WM_COMM_DSR_DETECTED WM_USER+3 // The DSR (data-set-ready) signal changed state.

#define WM_COMM_ERR_DETECTED WM_USER+4 // A line-status error occurred. Line-status errors are CE_FRAME, CE_OVERRUN, and CE_RXPARITY.

#define WM_COMM_RING_DETECTED WM_USER+5 // A ring indicator was detected.

#define WM_COMM_RLSD_DETECTED WM_USER+6 // The RLSD (receive-line-signal-detect) signal changed state.

#define WM_COMM_RXCHAR WM_USER+7 // A character was received and placed in the input buffer.

#define WM_COMM_RXFLAG_DETECTED WM_USER+8 // The event character was received and placed in the input buffer.

#define WM_COMM_TXEMPTY_DETECTED WM_USER+9 // The last character in the output buffer was sent.

class CSerialPort

{

public:

// contruction and destruction

CSerialPort();

virtual ~CSerialPort();

// port initialisation

BOOL InitPort(CWnd* pPortOwner, UINT portnr = 1, UINT baud = 19200, char parity = 'N', UINT databits = 8, UINT stopsbits = 1, DWORD dwCommEvents = EV_RXCHAR | EV_CTS, UINT nBufferSize = 512);

// start/stop comm watching

BOOL StartMonitoring();

BOOL RestartMonitoring();

BOOL StopMonitoring();

DWORD GetWriteBufferSize();

DWORD GetCommEvents();

DCB GetDCB();

void WriteToPort(char* string);

void WriteToPort(char* string,int stringlength);

protected:

// protected memberfunctions

void ProcessErrorMessage(char* ErrorText);

static UINT CommThread(LPVOID pParam);

static void ReceiveChar(CSerialPort* port, COMSTAT comstat);

static void WriteChar(CSerialPort* port);

// thread

CWinThread* m_Thread;

// synchronisation objects

CRITICAL_SECTION m_csCommunicationSync;

BOOL m_bThreadAlive;

// handles

HANDLE m_hShutdownEvent;

HANDLE m_hComm;

HANDLE m_hWriteEvent;

HANDLE m_hWriteCompleteEvent;

// Event array.

// One element is used for each event. There are two event handles for each port.

// A Write event and a receive character event which is located in the overlapped structure (m_ov.hEvent).

// There is a general shutdown when the port is closed.

HANDLE m_hEventArray[3];

// structures

OVERLAPPED m_ov;

COMMTIMEOUTS m_CommTimeouts;

DCB m_dcb;

// owner window

CWnd* m_pOwner;

// misc

UINT m_nPortNr;

char* m_szWriteBuffer;

DWORD m_dwCommEvents;

DWORD m_nWriteBufferSize;

int m_nActualWriteBufferSize;

};

#endif __SERIALPORT_H__

/*

** FILENAME CSerialPort.cpp

**

** PURPOSE This class can read, write and watch one serial port.

** It sends messages to its owner when something happends on the port

** The class creates a thread for reading and writing so the main

** program is not blocked.

**

** CREATION DATE 15-09-1997

** LAST MODIFICATION 24-11-1998

**

** AUTHOR Remon Spekreijse

** MODIFIED BY Brian Koh Sze Hsian

**

*/

#include "stdafx.h"

#include "SerialPort.h"

#include <assert.h>

//

// Constructor

//

CSerialPort::CSerialPort()

{

m_hComm = NULL;

// initialize overlapped structure members to zero

m_ov.Offset = 0;

m_ov.OffsetHigh = 0;

// create events

m_ov.hEvent = NULL;

m_hWriteEvent = NULL;

m_hShutdownEvent = NULL;

m_szWriteBuffer = NULL;

m_bThreadAlive = FALSE;

m_hWriteCompleteEvent=NULL;

}

//

// Delete dynamic memory

//

CSerialPort::~CSerialPort()

{

// resume the thread if it was suspended. Needed to process m_hShutdownEvent!

if(m_Thread != NULL)

{

DWORD dwSuspendCount;

do

{

dwSuspendCount = m_Thread->ResumeThread();

}

while((dwSuspendCount != 0) && (dwSuspendCount != 0xffffffff) );

do

{

SetEvent(m_hShutdownEvent);

}

while (m_bThreadAlive);

TRACE("Thread ended\n");

}

// close handles to avoid memory leaks

CloseHandle(m_ov.hEvent);

CloseHandle(m_hWriteEvent);

CloseHandle(m_hComm);

CloseHandle(m_hShutdownEvent);

CloseHandle(m_hWriteCompleteEvent);

m_hComm = NULL;

m_ov.hEvent = NULL;

m_hWriteEvent = NULL;

m_hShutdownEvent = NULL;

m_hWriteCompleteEvent = NULL;

if (m_szWriteBuffer != NULL)

delete [] m_szWriteBuffer;

DeleteCriticalSection(&m_csCommunicationSync);

}

//

// Initialize the port. This can be port 1 to 4.

//

BOOL CSerialPort::InitPort(CWnd* pPortOwner, // the owner (CWnd) of the port (receives message)

UINT portnr, // portnumber (1..4)

UINT baud, // baudrate

char parity, // parity

UINT databits, // databits

UINT stopbits, // stopbits

DWORD dwCommEvents, // EV_RXCHAR, EV_CTS etc

UINT writebuffersize) // size to the writebuffer

{

assert(portnr > 0 && portnr < 5);

assert(pPortOwner != NULL);

// if the thread is alive: Kill

if (m_bThreadAlive)

{

do

{

SetEvent(m_hShutdownEvent);

} while (m_bThreadAlive);

TRACE("Thread ended\n");

}

// create events

if (m_ov.hEvent != NULL)

ResetEvent(m_ov.hEvent);

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

if (m_hWriteEvent != NULL)

ResetEvent(m_hWriteEvent);

m_hWriteEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

if (m_hShutdownEvent != NULL)

ResetEvent(m_hShutdownEvent);

m_hShutdownEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

if(m_hWriteCompleteEvent != NULL)

ResetEvent(m_hWriteCompleteEvent);

m_hWriteCompleteEvent = CreateEvent(NULL, TRUE, FALSE, NULL);

// initialize the event objects

m_hEventArray[0] = m_hShutdownEvent; // highest priority

m_hEventArray[1] = m_ov.hEvent;

m_hEventArray[2] = m_hWriteEvent;

// initialize critical section

InitializeCriticalSection(&m_csCommunicationSync);

// set buffersize for writing and save the owner

m_pOwner = pPortOwner;

if (m_szWriteBuffer != NULL)

delete [] m_szWriteBuffer;

m_szWriteBuffer = new char[writebuffersize];

m_nPortNr = portnr;

m_nWriteBufferSize = writebuffersize;

m_dwCommEvents = dwCommEvents;

BOOL bResult = FALSE;

char *szPort = new char[50];

char *szBaud = new char[50];

// now it critical!

EnterCriticalSection(&m_csCommunicationSync);

// if the port is already opened: close it

if (m_hComm != NULL)

{

CloseHandle(m_hComm);

m_hComm = NULL;

}

// prepare port strings

sprintf(szPort, "COM%d", portnr);

sprintf(szBaud, "baud=%d parity=%c data=%d stop=%d", baud, parity, databits, stopbits);

// get a handle to the port

m_hComm = CreateFile(szPort, // communication port string (COMX)

GENERIC_READ | GENERIC_WRITE, // read/write types

0, // comm devices must be opened with exclusive access

NULL, // no security attributes

OPEN_EXISTING, // comm devices must use OPEN_EXISTING

FILE_FLAG_OVERLAPPED, // Async I/O

0); // template must be 0 for comm devices

if (m_hComm == INVALID_HANDLE_VALUE)

{

// port not found

delete [] szPort;

delete [] szBaud;

return FALSE;

}

// set the timeout values

m_CommTimeouts.ReadIntervalTimeout = 1000;

m_CommTimeouts.ReadTotalTimeoutMultiplier = 1000;

m_CommTimeouts.ReadTotalTimeoutConstant = 1000;

m_CommTimeouts.WriteTotalTimeoutMultiplier = 1000;

m_CommTimeouts.WriteTotalTimeoutConstant = 1000;

// configure

if (SetCommTimeouts(m_hComm, &m_CommTimeouts))

{

if (SetCommMask(m_hComm, dwCommEvents))

{

if (GetCommState(m_hComm, &m_dcb))

{

m_dcb.fRtsControl = RTS_CONTROL_ENABLE; // set RTS bit high!

if (BuildCommDCB(szBaud, &m_dcb))

{

if (SetCommState(m_hComm, &m_dcb))

; // normal operation... continue

else

ProcessErrorMessage("SetCommState()");

}

else

ProcessErrorMessage("BuildCommDCB()");

}

else

ProcessErrorMessage("GetCommState()");

}

else

ProcessErrorMessage("SetCommMask()");

}

else

ProcessErrorMessage("SetCommTimeouts()");

delete [] szPort;

delete [] szBaud;

// flush the port

PurgeComm(m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);

// release critical section

LeaveCriticalSection(&m_csCommunicationSync);

TRACE("Initialisation for communicationport %d completed.\nUse Startmonitor to communicate.\n", portnr);

return TRUE;

}

//

// The CommThread Function.

//

UINT CSerialPort::CommThread(LPVOID pParam)

{

// Cast the void pointer passed to the thread back to

// a pointer of CSerialPort class

CSerialPort *port = (CSerialPort*)pParam;

// Set the status variable in the dialog class to

// TRUE to indicate the thread is running.

port->m_bThreadAlive = TRUE;

// Misc. variables

DWORD BytesTransfered = 0;

DWORD Event = 0;

DWORD CommEvent = 0;

DWORD dwError = 0;

COMSTAT comstat;

BOOL bResult = TRUE;

// Clear comm buffers at startup

if (port->m_hComm) // check if the port is opened

PurgeComm(port->m_hComm, PURGE_RXCLEAR | PURGE_TXCLEAR | PURGE_RXABORT | PURGE_TXABORT);

// begin forever loop. This loop will run as long as the thread is alive.

for (;

{

// Make a call to WaitCommEvent(). This call will return immediatly

// because our port was created as an async port (FILE_FLAG_OVERLAPPED

// and an m_OverlappedStructerlapped structure specified). This call will cause the

// m_OverlappedStructerlapped element m_OverlappedStruct.hEvent, which is part of the m_hEventArray to

// be placed in a non-signeled state if there are no bytes available to be read,

// or to a signeled state if there are bytes available. If this event handle

// is set to the non-signeled state, it will be set to signeled when a

// character arrives at the port.

// we do this for each port!

bResult = WaitCommEvent(port->m_hComm, &Event, &port->m_ov);

if (!bResult)

{

// If WaitCommEvent() returns FALSE, process the last error to determin

// the reason..

switch (dwError = GetLastError())

{

case ERROR_IO_PENDING:

{

// This is a normal return value if there are no bytes

// to read at the port.

// Do nothing and continue

break;

}

case 87:

{

// Under Windows NT, this value is returned for some reason.

// I have not investigated why, but it is also a valid reply

// Also do nothing and continue.

break;

}

default:

{

// All other error codes indicate a serious error has

// occured. Process this error.

port->ProcessErrorMessage("WaitCommEvent()");

break;

}

}

}

else

{

// If WaitCommEvent() returns TRUE, check to be sure there are

// actually bytes in the buffer to read.

//

// If you are reading more than one byte at a time from the buffer

// (which this program does not do) you will have the situation occur

// where the first byte to arrive will cause the WaitForMultipleObjects()

// function to stop waiting. The WaitForMultipleObjects() function

// resets the event handle in m_OverlappedStruct.hEvent to the non-signelead state

// as it returns.

//

// If in the time between the reset of this event and the call to

// ReadFile() more bytes arrive, the m_OverlappedStruct.hEvent handle will be set again

// to the signeled state. When the call to ReadFile() occurs, it will

// read all of the bytes from the buffer, and the program will

// loop back around to WaitCommEvent().

//

// At this point you will be in the situation where m_OverlappedStruct.hEvent is set,

// but there are no bytes available to read. If you proceed and call

// ReadFile(), it will return immediatly due to the async port setup, but

// GetOverlappedResults() will not return until the next character arrives.

//

// It is not desirable for the GetOverlappedResults() function to be in

// this state. The thread shutdown event (event 0) and the WriteFile()

// event (Event2) will not work if the thread is blocked by GetOverlappedResults().

//

// The solution to this is to check the buffer with a call to ClearCommError().

// This call will reset the event handle, and if there are no bytes to read

// we can loop back through WaitCommEvent() again, then proceed.

// If there are really bytes to read, do nothing and proceed.

bResult = ClearCommError(port->m_hComm, &dwError, &comstat);

if (comstat.cbInQue == 0)

continue;

} // end if bResult

// Main wait function. This function will normally block the thread

// until one of nine events occur that require action.

Event = WaitForMultipleObjects(3, port->m_hEventArray, FALSE, INFINITE);

switch (Event)

{

case 0:

{

// Shutdown event. This is event zero so it will be

// the higest priority and be serviced first.

port->m_bThreadAlive = FALSE;

// Kill this thread. break is not needed, but makes me feel better.

AfxEndThread(100);

break;

}

case 1: // read event

{

GetCommMask(port->m_hComm, &CommEvent);

if (CommEvent & EV_CTS)

::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_CTS_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);

if (CommEvent & EV_RXFLAG)

::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RXFLAG_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);

if (CommEvent & EV_BREAK)

::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_BREAK_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);

if (CommEvent & EV_ERR)

::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_ERR_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);

if (CommEvent & EV_RING)

::SendMessage(port->m_pOwner->m_hWnd, WM_COMM_RING_DETECTED, (WPARAM) 0, (LPARAM) port->m_nPortNr);

if (CommEvent & EV_RXCHAR)

// Receive character event from port.

ReceiveChar(port, comstat);

break;

}

case 2: // write event

{

// 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_szWriteBuffer, // Pointer to message buffer in calling finction

port->m_nActualWriteBufferSize,

// strlen(port->m_szWriteBuffer), // Length of message to send

&BytesSent, // Where to store the number of bytes sent

&port->m_ov); // Overlapped structure

// deal with any error codes

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 != strlen((char*)port->m_szWriteBuffer))

{

TRACE("WARNING: WriteFile() error.. Bytes Sent: %d; Message Length: %d\n", BytesSent, strlen((char*)port->m_szWriteBuffer));

}

SetEvent(port->m_hWriteCompleteEvent);

}

//

// Character received. Inform the owner

//

void CSerialPort::ReceiveChar(CSerialPort* port, COMSTAT comstat)

{

BOOL bRead = TRUE;

BOOL bResult = TRUE;

DWORD dwError = 0;

DWORD BytesRead = 0;

unsigned char RXBuff;

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

&RXBuff, // RX Buffer Pointer

1, // 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);

// notify parent that a byte was received

::SendMessage((port->m_pOwner)->m_hWnd, WM_COMM_RXCHAR, (WPARAM) RXBuff, (LPARAM) port->m_nPortNr);

} // end forever loop

}

//

// Write a string to the port - This can write even NULL characters

//

void CSerialPort::WriteToPort(char* string, int stringlength)

{

assert(m_hComm != 0);

ResetEvent(m_hWriteCompleteEvent);

EnterCriticalSection(&m_csCommunicationSync);

memset(m_szWriteBuffer, 0, sizeof(m_szWriteBuffer));

for(int i=0;i<stringlength;i++)

m_szWriteBuffer=string;

m_nActualWriteBufferSize=stringlength;

LeaveCriticalSection(&m_csCommunicationSync);

// set event for write

SetEvent(m_hWriteEvent);

WaitForSingleObject(m_hWriteCompleteEvent,INFINITE);

}

//

// Return the device control block

//

DCB CSerialPort::GetDCB()

{

return m_dcb;

}

//

// Return the communication event masks

//

DWORD CSerialPort::GetCommEvents()

{

return m_dwCommEvents;

}

//

// Return the output buffer size

//

DWORD CSerialPort::GetWriteBufferSize()

{

return m_nWriteBufferSize;

}

[maddin]

erstmals danke werd ich gleich mal ausprobieren.bloß kannst du vielleicht noch die seite mit angeben.

------------------

mfg maddin