int xbee_ser_open( xbee_serial_t *serial, uint32_t baudrate)
{
int err;
if (serial == NULL)
{
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: NULL parameter, return -EINVAL\n", __FUNCTION__);
#endif
return -EINVAL;
}
// make sure device name is null terminated
serial->device[(sizeof serial->device) - 1] = '\0';
serial->fd = open( serial->device, O_RDWR | O_NOCTTY | O_NDELAY);
if (serial->fd < 0)
{
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: open('%s') failed (errno=%d)\n", __FUNCTION__,
serial->device, errno);
#endif
return -errno;
}
// Configure file descriptor to not block on read() if there aren't
// any characters available.
fcntl( serial->fd, F_SETFL, FNDELAY);
// reset port before setting actual baudrate
xbee_ser_baudrate( serial, 0);
err = xbee_ser_baudrate( serial, baudrate);
if (err)
{
return err;
}
return 0;
}
void next_baudrate( xbee_serial_t *port)
{
uint32_t rates[] = { 9600, 19200, 38400, 57600, 115200 };
int i;
for (i = 0; i < _TABLE_ENTRIES( rates); ++i)
{
if (port->baudrate == rates[i])
{
++i;
break;
}
}
// At end of loop, if port was using a rate not in the list above,
// the code will end up setting the baudrate to 9600.
xbee_ser_baudrate( port, rates[i % _TABLE_ENTRIES( rates)]);
print_baudrate( port);
}
int xbee_ser_open( xbee_serial_t *serial, uint32_t baudrate)
{
char buffer[sizeof("\\\\.\\COM9999")];
HANDLE hCom;
COMMTIMEOUTS timeouts;
int err;
if (serial == NULL || serial->comport > 9999)
{
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: -EINVAL (serial=%p)\n", __FUNCTION__, serial);
#endif
return -EINVAL;
}
// if XBee's existing hCom handle is not null, need to close it
// (unless we're just changing the baud rate?)
// Assume serial port has not changed if port is already open, and skip the
// CreateFile step.
if (serial->hCom)
{
// serial port is already open
hCom = serial->hCom;
serial->hCom = NULL;
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: port already open (hCom=%p)\n",
__FUNCTION__, hCom);
#endif
}
else
{
snprintf( buffer, sizeof buffer, "\\\\.\\COM%u", serial->comport);
hCom = CreateFile( buffer, GENERIC_READ | GENERIC_WRITE,
0, NULL, OPEN_EXISTING, FILE_ATTRIBUTE_NORMAL, NULL);
if (hCom == INVALID_HANDLE_VALUE)
{
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: error %lu opening handle to %s\n", __FUNCTION__,
GetLastError(), buffer);
#endif
return -EIO;
}
}
// set up a transmit and receive buffers
SetupComm( hCom, XBEE_SER_RX_BUFSIZE, XBEE_SER_TX_BUFSIZE);
/* Set the COMMTIMEOUTS structure. Per MSDN documentation for
ReadIntervalTimeout, "A value of MAXDWORD, combined with zero values
for both the ReadTotalTimeoutConstant and ReadTotalTimeoutMultiplier
members, specifies that the read operation is to return immediately
with the bytes that have already been received, even if no bytes have
been received."
*/
if (!GetCommTimeouts( hCom, &timeouts))
{
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: %s failed (%lu initializing COM%u)\n",
__FUNCTION__, "GetCommTimeouts", GetLastError(), serial->comport);
#endif
CloseHandle( hCom);
return -EIO;
}
timeouts.ReadIntervalTimeout = MAXDWORD;
timeouts.ReadTotalTimeoutMultiplier = 0;
timeouts.ReadTotalTimeoutConstant = 0;
if (!SetCommTimeouts( hCom, &timeouts))
{
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: %s failed (%lu initializing COM%u)\n",
__FUNCTION__, "SetCommTimeouts", GetLastError(), serial->comport);
#endif
CloseHandle( hCom);
return -EIO;
}
PurgeComm( hCom, PURGE_TXCLEAR | PURGE_TXABORT |
PURGE_RXCLEAR | PURGE_RXABORT);
serial->hCom = hCom;
err = xbee_ser_baudrate( serial, baudrate);
if (err)
{
serial->hCom = NULL;
return err;
}
#ifdef XBEE_SERIAL_VERBOSE
printf( "%s: SUCCESS COM%u opened (hCom=%p, baud=%u)\n",
__FUNCTION__, serial->comport, hCom, baudrate);
#endif
return 0;
}
