Bonjour,
je me permets de poster ce post concernant un programme pour lire sur le port COM1 ou 2.
mais ca ne fonctionne pas, il se met automatiquement en time out et n'effectue pas de loop do while tant qu'il n'y a rien dans le buffer du port serie a la reception.
voici le code.
[code]
#include "stdafx.h"
#include <windows.h>
#include <stdio.h>
#include <stdlib.h>
#include <conio.h>
#define RX_SIZE 4096 /* taille tampon d'entrée */
#define TX_SIZE 4096 /* taille tampon de sortie */
#define MAX_WAIT_READ 500 /* temps max d'attente pour lecture (en ms) */
bool WriteCom(void* buffer);
bool ReadCom() ;
HANDLE h_serialCOM = NULL;
int _tmain(int argc, _TCHAR* argv[])
{
COMMTIMEOUTS g_cto =
{
MAX_WAIT_READ, /* ReadIntervalTimeOut */
0, /* ReadTotalTimeOutMultiplier */
MAX_WAIT_READ, /* ReadTotalTimeOutConstant */
0, /* WriteTotalTimeOutMultiplier */
0 /* WriteTotalTimeOutConstant */
};
DCB g_dcb =
{
sizeof(DCB), /* DCBlength */
9600, /* BaudRate */
TRUE, /* fBinary */
FALSE, /* fParity */
FALSE, /* fOutxCtsFlow */
FALSE, /* fOutxDsrFlow */
DTR_CONTROL_DISABLE, /* fDtrControl */
FALSE, /* fDsrSensitivity */
FALSE, /* fTXContinueOnXoff */
FALSE, /* fOutX */
FALSE, /* fInX */
FALSE, /* fErrorChar */
FALSE, /* fNull */
RTS_CONTROL_DISABLE, /* fRtsControl */
FALSE, /* fAbortOnError */
0, /* fDummy2 */
0, /* wReserved */
0x100, /* XonLim */
0x100, /* XoffLim */
8, /* ByteSize */
NOPARITY, /* Parity */
ONESTOPBIT, /* StopBits */
0x11, /* XonChar */
0x13, /* XoffChar */
'?', /* ErrorChar */
0x1A, /* EofChar */
0x10 /* EvtChar */
};
h_serialCOM = CreateFile("COM2", GENERIC_READ|GENERIC_WRITE, 0, NULL,
OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
if(h_serialCOM == INVALID_HANDLE_VALUE)
{
printf("\nErreur lors de l'ouverture du port COM");
}
/* affectation taille des tampons d'émission et de réception */
SetupComm(h_serialCOM, RX_SIZE, TX_SIZE);
/* configuration du port COM */
if(!SetCommTimeouts(h_serialCOM, &g_cto) || !SetCommState(h_serialCOM, &g_dcb))
{
printf("\nErreur lors de la configuration du port COM");
CloseHandle(h_serialCOM);
}
/* on vide les tampons d'émission et de réception, mise à 1 DTR */
PurgeComm(h_serialCOM, PURGE_TXCLEAR|PURGE_RXCLEAR|PURGE_TXABORT|PURGE_RXABORT);
EscapeCommFunction(h_serialCOM, SETDTR);
ReadCom();
return 0;
}
bool ReadCom()
{
DWORD dwRead;
char lpBuf[50]={0};
bool fres=false;
bool fWaitingOnRead = false;
OVERLAPPED osReader = {0};
// Create the overlapped event. Must be closed before exiting
// to avoid a handle leak.
osReader.hEvent = CreateEvent(NULL, TRUE, FALSE, NULL);
if (osReader.hEvent == NULL)
return false;
// Error creating overlapped event; abort.
do
{if (!fWaitingOnRead)
{
// Issue read operation.
if (ReadFile(h_serialCOM, lpBuf, 1, &dwRead, &osReader)==false)
{
if (GetLastError() != ERROR_IO_PENDING) // read not delayed?
// Error in communications; report it.
printf ("erreur de com");
else
fWaitingOnRead = true;//signaled
}
else {
// read completed immediately
printf("succes reception :%s",lpBuf);
fres=true;
}
}
if (fWaitingOnRead)
{
DWORD dwRes = WaitForSingleObject(osReader.hEvent, 500);
switch(dwRes)
{
// Read completed.
case WAIT_OBJECT_0:
if (!GetOverlappedResult(h_serialCOM, &osReader, &dwRead, FALSE))
// Read completed successfully.
printf("\n succes reception :%s",lpBuf);
// Reset flag so that another opertion can be issued.
fWaitingOnRead = false;
fres = true;
break;
case WAIT_TIMEOUT:
printf("\n time out");
// Operation isn't complete yet. fWaitingOnRead flag isn't
// changed since I'll loop back around, and I don't want
// to issue another read until the first one finishes.
//
// This is a good time to do some background work.
fres = false;
break;
default:
// Error in the WaitForSingleObject; abort.
// This indicates a problem with the OVERLAPPED structure's
// event handle.
printf("\n DEFAULT");
fres = false;
break;
}
}
}
while(fres=false);
}
[/code]
il ya surement quelquechose qui deconne dans le commtimeout ou bien dans le do while de test readfile.
Comme vous avez pu le constater j'ai essayer de respecter a la lettre l'article sur msdn.
merci
kix