def open(self):
"""Open port with current settings. This may throw a SerialException
if the port cannot be opened."""
if self._port is None:
raise SerialException("Port must be configured before it can be used.")
if self._isOpen:
raise SerialException("Port is already open.")
# the "\\.\COMx" format is required for devices other than COM1-COM8
# not all versions of windows seem to support this properly
# so that the first few ports are used with the DOS device name
port = self.portstr
try:
if port.upper().startswith('COM') and int(port[3:]) > 8:
port = '\\\\.\\' + port
except ValueError:
# for like COMnotanumber
pass
self.hComPort = win32.CreateFile(port,
win32.GENERIC_READ | win32.GENERIC_WRITE,
0, # exclusive access
None, # no security
win32.OPEN_EXISTING,
win32.FILE_ATTRIBUTE_NORMAL | win32.FILE_FLAG_OVERLAPPED,
0)
if self.hComPort == win32.INVALID_HANDLE_VALUE:
self.hComPort = None # 'cause __del__ is called anyway
raise SerialException("could not open port %r: %r" % (self.portstr, ctypes.WinError()))
try:
self._overlappedRead = win32.OVERLAPPED()
self._overlappedRead.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlappedWrite = win32.OVERLAPPED()
#~ self._overlappedWrite.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlappedWrite.hEvent = win32.CreateEvent(None, 0, 0, None)
# Setup a 4k buffer
win32.SetupComm(self.hComPort, 4096, 4096)
# Save original timeout values:
self._orgTimeouts = win32.COMMTIMEOUTS()
win32.GetCommTimeouts(self.hComPort, ctypes.byref(self._orgTimeouts))
self._reconfigurePort()
# Clear buffers:
# Remove anything that was there
win32.PurgeComm(self.hComPort,
win32.PURGE_TXCLEAR | win32.PURGE_TXABORT |
win32.PURGE_RXCLEAR | win32.PURGE_RXABORT)
except:
try:
self._close()
except:
# ignore any exception when closing the port
# also to keep original exception that happened when setting up
pass
self.hComPort = None
raise
else:
self._isOpen = True
def _reconfigurePort(self):
"""Set communication parameters on opened port."""
if not self.hComPort:
raise SerialException("Can only operate on a valid port handle")
# Set Windows timeout values
# timeouts is a tuple with the following items:
# (ReadIntervalTimeout,ReadTotalTimeoutMultiplier,
# ReadTotalTimeoutConstant,WriteTotalTimeoutMultiplier,
# WriteTotalTimeoutConstant)
if self._timeout is None:
timeouts = (0, 0, 0, 0, 0)
elif self._timeout == 0:
timeouts = (win32.MAXDWORD, 0, 0, 0, 0)
else:
timeouts = (0, 0, int(self._timeout*1000), 0, 0)
if self._timeout != 0 and self._interCharTimeout is not None:
timeouts = (int(self._interCharTimeout * 1000),) + timeouts[1:]
if self._writeTimeout is None:
pass
elif self._writeTimeout == 0:
timeouts = timeouts[:-2] + (0, win32.MAXDWORD)
else:
timeouts = timeouts[:-2] + (0, int(self._writeTimeout*1000))
win32.SetCommTimeouts(self.hComPort, ctypes.byref(win32.COMMTIMEOUTS(*timeouts)))
win32.SetCommMask(self.hComPort, win32.EV_ERR)
# Setup the connection info.
# Get state and modify it:
comDCB = win32.DCB()
win32.GetCommState(self.hComPort, ctypes.byref(comDCB))
comDCB.BaudRate = self._baudrate
if self._bytesize == FIVEBITS:
comDCB.ByteSize = 5
elif self._bytesize == SIXBITS:
comDCB.ByteSize = 6
elif self._bytesize == SEVENBITS:
comDCB.ByteSize = 7
elif self._bytesize == EIGHTBITS:
comDCB.ByteSize = 8
else:
raise ValueError("Unsupported number of data bits: %r" % self._bytesize)
if self._parity == PARITY_NONE:
comDCB.Parity = win32.NOPARITY
comDCB.fParity = 0 # Disable Parity Check
elif self._parity == PARITY_EVEN:
comDCB.Parity = win32.EVENPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == PARITY_ODD:
comDCB.Parity = win32.ODDPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == PARITY_MARK:
comDCB.Parity = win32.MARKPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == PARITY_SPACE:
comDCB.Parity = win32.SPACEPARITY
comDCB.fParity = 1 # Enable Parity Check
else:
raise ValueError("Unsupported parity mode: %r" % self._parity)
if self._stopbits == STOPBITS_ONE:
comDCB.StopBits = win32.ONESTOPBIT
elif self._stopbits == STOPBITS_ONE_POINT_FIVE:
comDCB.StopBits = win32.ONE5STOPBITS
elif self._stopbits == STOPBITS_TWO:
comDCB.StopBits = win32.TWOSTOPBITS
else:
raise ValueError("Unsupported number of stop bits: %r" % self._stopbits)
comDCB.fBinary = 1 # Enable Binary Transmission
# Char. w/ Parity-Err are replaced with 0xff (if fErrorChar is set to TRUE)
if self._rtscts:
comDCB.fRtsControl = win32.RTS_CONTROL_HANDSHAKE
elif self._rtsToggle:
comDCB.fRtsControl = win32.RTS_CONTROL_TOGGLE
else:
comDCB.fRtsControl = self._rtsState
if self._dsrdtr:
comDCB.fDtrControl = win32.DTR_CONTROL_HANDSHAKE
else:
comDCB.fDtrControl = self._dtrState
if self._rtsToggle:
comDCB.fOutxCtsFlow = 0
else:
comDCB.fOutxCtsFlow = self._rtscts
comDCB.fOutxDsrFlow = self._dsrdtr
comDCB.fOutX = self._xonxoff
comDCB.fInX = self._xonxoff
comDCB.fNull = 0
comDCB.fErrorChar = 0
comDCB.fAbortOnError = 0
comDCB.XonChar = XON
comDCB.XoffChar = XOFF
if not win32.SetCommState(self.hComPort, ctypes.byref(comDCB)):
raise ValueError("Cannot configure port, some setting was wrong. Original message: %r" % ctypes.WinError())
def _reconfigure_port(self):
"""Set communication parameters on opened port."""
if not self._port_handle:
raise SerialException("Can only operate on a valid port handle")
# Set Windows timeout values
# timeouts is a tuple with the following items:
# (ReadIntervalTimeout,ReadTotalTimeoutMultiplier,
# ReadTotalTimeoutConstant,WriteTotalTimeoutMultiplier,
# WriteTotalTimeoutConstant)
timeouts = win32.COMMTIMEOUTS()
if self._timeout is None:
pass # default of all zeros is OK
elif self._timeout == 0:
timeouts.ReadIntervalTimeout = win32.MAXDWORD
else:
timeouts.ReadTotalTimeoutConstant = max(int(self._timeout * 1000),
1)
if self._timeout != 0 and self._inter_byte_timeout is not None:
timeouts.ReadIntervalTimeout = max(
int(self._inter_byte_timeout * 1000), 1)
if self._write_timeout is None:
pass
elif self._write_timeout == 0:
timeouts.WriteTotalTimeoutConstant = win32.MAXDWORD
else:
timeouts.WriteTotalTimeoutConstant = max(
int(self._write_timeout * 1000), 1)
win32.SetCommTimeouts(self._port_handle, ctypes.byref(timeouts))
win32.SetCommMask(self._port_handle, win32.EV_ERR)
# Setup the connection info.
# Get state and modify it:
comDCB = win32.DCB()
win32.GetCommState(self._port_handle, ctypes.byref(comDCB))
comDCB.BaudRate = self._baudrate
if self._bytesize == serial.FIVEBITS:
comDCB.ByteSize = 5
elif self._bytesize == serial.SIXBITS:
comDCB.ByteSize = 6
elif self._bytesize == serial.SEVENBITS:
comDCB.ByteSize = 7
elif self._bytesize == serial.EIGHTBITS:
comDCB.ByteSize = 8
else:
raise ValueError("Unsupported number of data bits: {!r}".format(
self._bytesize))
if self._parity == serial.PARITY_NONE:
comDCB.Parity = win32.NOPARITY
comDCB.fParity = 0 # Disable Parity Check
elif self._parity == serial.PARITY_EVEN:
comDCB.Parity = win32.EVENPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == serial.PARITY_ODD:
comDCB.Parity = win32.ODDPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == serial.PARITY_MARK:
comDCB.Parity = win32.MARKPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == serial.PARITY_SPACE:
comDCB.Parity = win32.SPACEPARITY
comDCB.fParity = 1 # Enable Parity Check
else:
raise ValueError("Unsupported parity mode: {!r}".format(
self._parity))
if self._stopbits == serial.STOPBITS_ONE:
comDCB.StopBits = win32.ONESTOPBIT
elif self._stopbits == serial.STOPBITS_ONE_POINT_FIVE:
comDCB.StopBits = win32.ONE5STOPBITS
elif self._stopbits == serial.STOPBITS_TWO:
comDCB.StopBits = win32.TWOSTOPBITS
else:
raise ValueError("Unsupported number of stop bits: {!r}".format(
self._stopbits))
comDCB.fBinary = 1 # Enable Binary Transmission
# Char. w/ Parity-Err are replaced with 0xff (if fErrorChar is set to TRUE)
if self._rs485_mode is None:
if self._rtscts:
comDCB.fRtsControl = win32.RTS_CONTROL_HANDSHAKE
else:
comDCB.fRtsControl = win32.RTS_CONTROL_ENABLE if self._rts_state else win32.RTS_CONTROL_DISABLE
comDCB.fOutxCtsFlow = self._rtscts
else:
# checks for unsupported settings
# XXX verify if platform really does not have a setting for those
if not self._rs485_mode.rts_level_for_tx:
raise ValueError(
'Unsupported value for RS485Settings.rts_level_for_tx: {!r}'
.format(self._rs485_mode.rts_level_for_tx, ))
if self._rs485_mode.rts_level_for_rx:
raise ValueError(
'Unsupported value for RS485Settings.rts_level_for_rx: {!r}'
.format(self._rs485_mode.rts_level_for_rx, ))
if self._rs485_mode.delay_before_tx is not None:
raise ValueError(
'Unsupported value for RS485Settings.delay_before_tx: {!r}'
.format(self._rs485_mode.delay_before_tx, ))
if self._rs485_mode.delay_before_rx is not None:
raise ValueError(
'Unsupported value for RS485Settings.delay_before_rx: {!r}'
.format(self._rs485_mode.delay_before_rx, ))
if self._rs485_mode.loopback:
raise ValueError(
'Unsupported value for RS485Settings.loopback: {!r}'.
format(self._rs485_mode.loopback, ))
comDCB.fRtsControl = win32.RTS_CONTROL_TOGGLE
comDCB.fOutxCtsFlow = 0
if self._dsrdtr:
comDCB.fDtrControl = win32.DTR_CONTROL_HANDSHAKE
else:
comDCB.fDtrControl = win32.DTR_CONTROL_ENABLE if self._dtr_state else win32.DTR_CONTROL_DISABLE
comDCB.fOutxDsrFlow = self._dsrdtr
comDCB.fOutX = self._xonxoff
comDCB.fInX = self._xonxoff
comDCB.fNull = 0
comDCB.fErrorChar = 0
comDCB.fAbortOnError = 0
comDCB.XonChar = serial.XON
comDCB.XoffChar = serial.XOFF
if not win32.SetCommState(self._port_handle, ctypes.byref(comDCB)):
raise SerialException(
'Cannot configure port, something went wrong. '
'Original message: {!r}'.format(ctypes.WinError()))