rs232.c File Reference

#include <windows.h>
#include <winioctl.h>
#include <tchar.h>
#include <stdio.h>
#include "rs232.h"

Include dependency graph for rs232.c:

Go to the source code of this file.

Functions
BOOL	Rs232OpenPortWin32 (TCHAR *CommPort)
BOOL	Rs232ClosePortWin32 (VOID)
BOOL	Rs232ConfigurePortWin32 (TCHAR *DeviceControlString)
BOOL	Rs232SetCommunicationTimeoutsWin32 (DWORD ReadIntervalTimeout, DWORD ReadTotalTimeoutMultiplier, DWORD ReadTotalTimeoutConstant, DWORD WriteTotalTimeoutMultiplier, DWORD WriteTotalTimeoutConstant)
BOOL	Rs232ReadByteWin32 (BYTE *DataByte)
BOOL	Rs232WriteByteWin32 (BYTE DataByte)

Variables
HANDLE	hPortHandle = NULL

Function Documentation

Rs232ClosePortWin32()

BOOL Rs232ClosePortWin32

(

VOID

)

Definition at line 68 of file rs232.c.

{
    HANDLE    hTempPortHandle = hPortHandle;
 
    hPortHandle = NULL;
 
    if (hTempPortHandle == NULL)
    {
        return FALSE;
    }
 
    return CloseHandle(hTempPortHandle);
}

Referenced by Rs232Thread().

Rs232ConfigurePortWin32()

BOOL Rs232ConfigurePortWin32

(

TCHAR *

DeviceControlString

)

Definition at line 96 of file rs232.c.

{
    DCB        dcb;
    DWORD    ErrorCode;
 
#if 0
    if (!GetCommState(hPortHandle, &dcb))
    {
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("GetCommState() failed. GetLastError() = %lu.\n"), ErrorCode);
 
        return FALSE;
    }
 
    dcb.BaudRate = BaudRate;
    dcb.ByteSize = DataBits;
    dcb.Parity = Parity;
    dcb.StopBits = StopBits;
    dcb.fBinary = TRUE;
    dcb.fDsrSensitivity = FALSE;
    dcb.fParity = (Parity == NOPARITY) ? FALSE : TRUE;
    dcb.fOutX = FALSE;
    dcb.fInX = FALSE;
    dcb.fNull = FALSE;
    dcb.fAbortOnError = TRUE;
    dcb.fOutxCtsFlow = FALSE;
    dcb.fOutxDsrFlow = FALSE;
    dcb.fDtrControl = DTR_CONTROL_DISABLE;
    dcb.fDsrSensitivity = FALSE;
    dcb.fRtsControl = RTS_CONTROL_DISABLE;
    dcb.fOutxCtsFlow = FALSE;
    dcb.fOutxCtsFlow = FALSE;
#endif
 
    ZeroMemory(&dcb, sizeof(dcb));
    dcb.DCBlength = sizeof(dcb);
    if (!BuildCommDCB(DeviceControlString, &dcb))
    {
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("BuildCommDCB() failed. GetLastError() = %lu.\n"), ErrorCode);
 
        return FALSE;
    }
 
    if (!SetCommState(hPortHandle, &dcb))
    {
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("SetCommState() failed. GetLastError() = %lu.\n"), ErrorCode);
 
        return FALSE;
    }
 
    // Set the timeouts
    if (!Rs232SetCommunicationTimeoutsWin32(MAXDWORD, 0, 0, 0, 0))
    {
        return FALSE;
    }
 
    return TRUE;
}

Referenced by Rs232Thread().

Rs232OpenPortWin32()

BOOL Rs232OpenPortWin32

(

TCHAR *

CommPort

)

Definition at line 32 of file rs232.c.

{
    TCHAR    PortName[MAX_PATH];
    DWORD    ErrorCode;
 
    // First check and make sure they don't already have the
    // OBD2 connection open. We don't want to open things twice.
    if (hPortHandle != NULL)
    {
        _tprintf(TEXT("Port handle not NULL. Must be already open. Returning FALSE...\n"));
        return FALSE;
    }
 
    _stprintf(PortName, TEXT("\\\\.\\%s"), CommPort);
 
    hPortHandle = CreateFile(PortName,
                            GENERIC_READ|GENERIC_WRITE,
                            0,
                            0,
                            OPEN_EXISTING,
                            0,
                            0);
 
    if (hPortHandle == INVALID_HANDLE_VALUE)
    {
        hPortHandle = NULL;
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("CreateFile(\"%s\") failed. GetLastError() = %lu.\n"), PortName, ErrorCode);
 
        return FALSE;
    }
 
    return TRUE;
}

Referenced by Rs232Thread().

Rs232ReadByteWin32()

BOOL Rs232ReadByteWin32

(

BYTE *

DataByte

)

Definition at line 215 of file rs232.c.

{
    DWORD    BytesRead = 0;
    DWORD    ErrorCode;
 
    // If ReadFile() fails then report error
    if (!ReadFile(hPortHandle, DataByte, 1, &BytesRead, NULL))
    {
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("ReadFile() failed. GetLastError() = %lu.\n"), ErrorCode);
 
        return FALSE;
    }
 
    // If ReadFile() succeeds, but BytesRead isn't 1
    // then a timeout occurred.
    if (BytesRead != 1)
    {
        return FALSE;
    }
 
    return TRUE;
}

Referenced by Rs232Thread().

Rs232SetCommunicationTimeoutsWin32()

BOOL Rs232SetCommunicationTimeoutsWin32	(	DWORD	ReadIntervalTimeout,
		DWORD	ReadTotalTimeoutMultiplier,
		DWORD	ReadTotalTimeoutConstant,
		DWORD	WriteTotalTimeoutMultiplier,
		DWORD	WriteTotalTimeoutConstant
	)

Definition at line 183 of file rs232.c.

{
    COMMTIMEOUTS    ct;
    DWORD            ErrorCode;
 
    if (!GetCommTimeouts(hPortHandle, &ct))
    {
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("GetCommTimeouts() failed. GetLastError() = %lu.\n"), ErrorCode);
 
        return FALSE;
    }
 
    ct.ReadIntervalTimeout = ReadIntervalTimeout;
    ct.ReadTotalTimeoutConstant = ReadTotalTimeoutConstant;
    ct.ReadTotalTimeoutMultiplier = ReadTotalTimeoutMultiplier;
    ct.WriteTotalTimeoutConstant = WriteTotalTimeoutConstant;
    ct.WriteTotalTimeoutMultiplier = WriteTotalTimeoutMultiplier;
 
    if (!SetCommTimeouts(hPortHandle, &ct))
    {
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("SetCommTimeouts() failed. GetLastError() = %lu.\n"), ErrorCode);
 
        return FALSE;
    }
 
    return TRUE;
}

Referenced by Rs232ConfigurePortWin32().

Rs232WriteByteWin32()

BOOL Rs232WriteByteWin32

(

BYTE

DataByte

)

Definition at line 240 of file rs232.c.

{
    DWORD    BytesWritten = 0;
    BOOL    Success;
    DWORD    ErrorCode;
 
    Success = WriteFile(hPortHandle, &DataByte, 1, &BytesWritten, NULL);
 
    if (!Success || BytesWritten != 1)
    {
        ErrorCode = GetLastError();
 
        _tprintf(TEXT("WriteFile() failed. GetLastError() = %lu.\n"), ErrorCode);
 
        return FALSE;
    }
 
    return TRUE;
}

Referenced by Rs232Thread().

Variable Documentation

hPortHandle

HANDLE hPortHandle = NULL

Definition at line 29 of file rs232.c.

Referenced by Rs232ClosePortWin32(), Rs232ConfigurePortWin32(), Rs232OpenPortWin32(), Rs232ReadByteWin32(), Rs232SetCommunicationTimeoutsWin32(), and Rs232WriteByteWin32().