def write(self, data):
"""Output the given byte string over the serial port."""
if not self.is_open:
raise portNotOpenError
d = to_bytes(data)
tx_len = length = len(d)
timeout = Timeout(self._write_timeout)
while tx_len > 0:
try:
n = os.write(self.fd, d)
if timeout.is_non_blocking:
# Zero timeout indicates non-blocking - simply return the
# number of bytes of data actually written
return n
elif not timeout.is_infinite:
# when timeout is set, use select to wait for being ready
# with the time left as timeout
if timeout.expired():
raise writeTimeoutError
abort, ready, _ = select.select([self.pipe_abort_write_r],
[self.fd], [],
timeout.time_left())
if abort:
os.read(self.pipe_abort_write_r, 1000)
break
if not ready:
raise writeTimeoutError
else:
assert timeout.time_left() is None
# wait for write operation
abort, ready, _ = select.select([self.pipe_abort_write_r],
[self.fd], [], None)
if abort:
os.read(self.pipe_abort_write_r, 1)
break
if not ready:
raise SerialException('write failed (select)')
d = d[n:]
tx_len -= n
except SerialException:
raise
except OSError as e:
# this is for Python 3.x where select.error is a subclass of
# OSError ignore BlockingIOErrors and EINTR. other errors are shown
# https://www.python.org/dev/peps/pep-0475.
if e.errno not in (errno.EAGAIN, errno.EALREADY,
errno.EWOULDBLOCK, errno.EINPROGRESS,
errno.EINTR):
raise SerialException('write failed: {}'.format(e))
except select.error as e:
# this is for Python 2.x
# ignore BlockingIOErrors and EINTR. all errors are shown
# see also http://www.python.org/dev/peps/pep-3151/#select
if e[0] not in (errno.EAGAIN, errno.EALREADY,
errno.EWOULDBLOCK, errno.EINPROGRESS,
errno.EINTR):
raise SerialException('write failed: {}'.format(e))
if not timeout.is_non_blocking and timeout.expired():
raise writeTimeoutError
return length - len(d)
def read(self, size=1):
"""\
Read size bytes from the serial port. If a timeout is set it may
return less characters as requested. With no timeout it will block
until the requested number of bytes is read.
"""
if not self.is_open:
raise portNotOpenError
read = bytearray()
timeout = Timeout(self._timeout)
while len(read) < size:
try:
ready, _, _ = select.select([self.fd, self.pipe_abort_read_r],
[], [], timeout.time_left())
if self.pipe_abort_read_r in ready:
os.read(self.pipe_abort_read_r, 1000)
break
# If select was used with a timeout, and the timeout occurs, it
# returns with empty lists -> thus abort read operation.
# For timeout == 0 (non-blocking operation) also abort when
# there is nothing to read.
if not ready:
break # timeout
buf = os.read(self.fd, size - len(read))
# read should always return some data as select reported it was
# ready to read when we get to this point.
if not buf:
# Disconnected devices, at least on Linux, show the
# behavior that they are always ready to read immediately
# but reading returns nothing.
raise SerialException(
'device reports readiness to read but returned no data '
'(device disconnected or multiple access on port?)')
read.extend(buf)
except OSError as e:
# this is for Python 3.x where select.error is a subclass of
# OSError ignore BlockingIOErrors and EINTR. other errors are shown
# https://www.python.org/dev/peps/pep-0475.
if e.errno not in (errno.EAGAIN, errno.EALREADY,
errno.EWOULDBLOCK, errno.EINPROGRESS,
errno.EINTR):
raise SerialException('read failed: {}'.format(e))
except select.error as e:
# this is for Python 2.x
# ignore BlockingIOErrors and EINTR. all errors are shown
# see also http://www.python.org/dev/peps/pep-3151/#select
if e[0] not in (errno.EAGAIN, errno.EALREADY,
errno.EWOULDBLOCK, errno.EINPROGRESS,
errno.EINTR):
raise SerialException('read failed: {}'.format(e))
if timeout.expired():
break
return bytes(read)
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.is_open:
raise SerialException("Port is already open.")
self.fd = None
# open
try:
self.fd = os.open(self.portstr,
os.O_RDWR | os.O_NOCTTY | os.O_NONBLOCK)
except OSError as msg:
self.fd = None
raise SerialException(
msg.errno,
"could not open port {}: {}".format(self._port, msg))
#~ fcntl.fcntl(self.fd, fcntl.F_SETFL, 0) # set blocking
try:
self._reconfigure_port(force_update=True)
except:
try:
os.close(self.fd)
except:
# ignore any exception when closing the port
# also to keep original exception that happened when setting up
pass
self.fd = None
raise
else:
self.is_open = True
try:
if not self._dsrdtr:
self._update_dtr_state()
if not self._rtscts:
self._update_rts_state()
except IOError as e:
if e.errno in (errno.EINVAL, errno.ENOTTY):
# ignore Invalid argument and Inappropriate ioctl
pass
else:
raise
self.reset_input_buffer()
self.pipe_abort_read_r, self.pipe_abort_read_w = os.pipe()
self.pipe_abort_write_r, self.pipe_abort_write_w = os.pipe()
fcntl.fcntl(self.pipe_abort_read_r, fcntl.F_SETFL, os.O_NONBLOCK)
fcntl.fcntl(self.pipe_abort_write_r, fcntl.F_SETFL, os.O_NONBLOCK)
def _reconfigure_port(self, force_update=True):
"""Set communication parameters on opened port."""
super(VTIMESerial, self)._reconfigure_port()
fcntl.fcntl(self.fd, fcntl.F_SETFL, 0) # clear O_NONBLOCK
if self._inter_byte_timeout is not None:
vmin = 1
vtime = int(self._inter_byte_timeout * 10)
elif self._timeout is None:
vmin = 1
vtime = 0
else:
vmin = 0
vtime = int(self._timeout * 10)
try:
orig_attr = termios.tcgetattr(self.fd)
iflag, oflag, cflag, lflag, ispeed, ospeed, cc = orig_attr
except termios.error as msg: # if a port is nonexistent but has a /dev file, it'll fail here
raise SerialException("Could not configure port: {}".format(msg))
if vtime < 0 or vtime > 255:
raise ValueError('Invalid vtime: {!r}'.format(vtime))
cc[termios.VTIME] = vtime
cc[termios.VMIN] = vmin
termios.tcsetattr(self.fd, termios.TCSANOW,
[iflag, oflag, cflag, lflag, ispeed, ospeed, cc])
def read(self, size=1):
"""\
Read size bytes from the serial port. If a timeout is set it may
return less characters as requested. With no timeout it will block
until the requested number of bytes is read.
"""
if not self.is_open:
raise portNotOpenError
read = bytearray()
poll = select.poll()
poll.register(
self.fd,
select.POLLIN | select.POLLERR | select.POLLHUP | select.POLLNVAL)
if size > 0:
while len(read) < size:
# print "\tread(): size",size, "have", len(read) #debug
# wait until device becomes ready to read (or something fails)
for fd, event in poll.poll(self._timeout * 1000):
if event & (select.POLLERR | select.POLLHUP
| select.POLLNVAL):
raise SerialException('device reports error (poll)')
# we don't care if it is select.POLLIN or timeout, that's
# handled below
buf = os.read(self.fd, size - len(read))
read.extend(buf)
if ((self._timeout is not None and self._timeout >= 0) or
(self._inter_byte_timeout is not None
and self._inter_byte_timeout > 0)) and not buf:
break # early abort on timeout
return bytes(read)
def write(self, data):
"""Output the given byte string over the serial port."""
if not self.is_open:
raise portNotOpenError
#~ if not isinstance(data, (bytes, bytearray)):
#~ raise TypeError('expected %s or bytearray, got %s' % (bytes, type(data)))
# convert data (needed in case of memoryview instance: Py 3.1 io lib), ctypes doesn't like memoryview
data = to_bytes(data)
if data:
#~ win32event.ResetEvent(self._overlapped_write.hEvent)
n = win32.DWORD()
success = win32.WriteFile(self._port_handle, data, len(data),
ctypes.byref(n), self._overlapped_write)
if self._write_timeout != 0: # if blocking (None) or w/ write timeout (>0)
if not success and win32.GetLastError() not in (
win32.ERROR_SUCCESS, win32.ERROR_IO_PENDING):
raise SerialException("WriteFile failed ({!r})".format(
ctypes.WinError()))
# Wait for the write to complete.
#~ win32.WaitForSingleObject(self._overlapped_write.hEvent, win32.INFINITE)
win32.GetOverlappedResult(self._port_handle,
self._overlapped_write,
ctypes.byref(n), True)
if win32.GetLastError() == win32.ERROR_OPERATION_ABORTED:
return n.value # canceled IO is no error
if n.value != len(data):
raise writeTimeoutError
return n.value
else:
errorcode = win32.ERROR_SUCCESS if success else win32.GetLastError(
)
if errorcode in (win32.ERROR_INVALID_USER_BUFFER,
win32.ERROR_NOT_ENOUGH_MEMORY,
win32.ERROR_OPERATION_ABORTED):
return 0
elif errorcode in (win32.ERROR_SUCCESS,
win32.ERROR_IO_PENDING):
# no info on true length provided by OS function in async mode
return len(data)
else:
raise SerialException("WriteFile failed ({!r})".format(
ctypes.WinError()))
else:
return 0
def out_waiting(self):
"""Return how many bytes the in the outgoing buffer"""
flags = win32.DWORD()
comstat = win32.COMSTAT()
if not win32.ClearCommError(self._port_handle, ctypes.byref(flags),
ctypes.byref(comstat)):
raise SerialException("ClearCommError failed ({!r})".format(
ctypes.WinError()))
return comstat.cbOutQue
def in_waiting(self):
"""Return the number of bytes currently in the input buffer."""
flags = win32.DWORD()
comstat = win32.COMSTAT()
if not win32.ClearCommError(self._port_handle, ctypes.byref(flags),
ctypes.byref(comstat)):
raise SerialException("ClearCommError failed ({!r})".format(
ctypes.WinError()))
return comstat.cbInQue
def read(self, size=1):
"""\
Read size bytes from the serial port. If a timeout is set it may
return less characters as requested. With no timeout it will block
until the requested number of bytes is read.
"""
if not self.is_open:
raise portNotOpenError
if size > 0:
win32.ResetEvent(self._overlapped_read.hEvent)
flags = win32.DWORD()
comstat = win32.COMSTAT()
if not win32.ClearCommError(self._port_handle, ctypes.byref(flags),
ctypes.byref(comstat)):
raise SerialException("ClearCommError failed ({!r})".format(
ctypes.WinError()))
n = min(comstat.cbInQue, size) if self.timeout == 0 else size
if n > 0:
buf = ctypes.create_string_buffer(n)
rc = win32.DWORD()
read_ok = win32.ReadFile(self._port_handle, buf, n,
ctypes.byref(rc),
ctypes.byref(self._overlapped_read))
if not read_ok and win32.GetLastError() not in (
win32.ERROR_SUCCESS, win32.ERROR_IO_PENDING):
raise SerialException("ReadFile failed ({!r})".format(
ctypes.WinError()))
result_ok = win32.GetOverlappedResult(
self._port_handle, ctypes.byref(self._overlapped_read),
ctypes.byref(rc), True)
if not result_ok:
if win32.GetLastError() != win32.ERROR_OPERATION_ABORTED:
raise SerialException(
"GetOverlappedResult failed ({!r})".format(
ctypes.WinError()))
read = buf.raw[:rc.value]
else:
read = bytes()
else:
read = bytes()
return bytes(read)
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.")
self.fd = None
# open
try:
self.fd = os.open(self.portstr,
os.O_RDWR | os.O_NOCTTY | os.O_NONBLOCK)
except Exception as msg:
self.fd = None
raise SerialException("could not open port %s: %s" %
(self._port, msg))
# ~ fcntl.fcntl(self.fd, FCNTL.F_SETFL, 0) #set blocking
try:
self._reconfigurePort()
except BaseException:
os.close(self.fd)
self.fd = None
else:
self._isOpen = True
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 == serialutil.FIVEBITS:
comDCB.ByteSize = 5
elif self._bytesize == serialutil.SIXBITS:
comDCB.ByteSize = 6
elif self._bytesize == serialutil.SEVENBITS:
comDCB.ByteSize = 7
elif self._bytesize == serialutil.EIGHTBITS:
comDCB.ByteSize = 8
else:
raise ValueError("Unsupported number of data bits: {!r}".format(
self._bytesize))
if self._parity == serialutil.PARITY_NONE:
comDCB.Parity = win32.NOPARITY
comDCB.fParity = 0 # Disable Parity Check
elif self._parity == serialutil.PARITY_EVEN:
comDCB.Parity = win32.EVENPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == serialutil.PARITY_ODD:
comDCB.Parity = win32.ODDPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == serialutil.PARITY_MARK:
comDCB.Parity = win32.MARKPARITY
comDCB.fParity = 1 # Enable Parity Check
elif self._parity == serialutil.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 == serialutil.STOPBITS_ONE:
comDCB.StopBits = win32.ONESTOPBIT
elif self._stopbits == serialutil.STOPBITS_ONE_POINT_FIVE:
comDCB.StopBits = win32.ONE5STOPBITS
elif self._stopbits == serialutil.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 = serialutil.XON
comDCB.XoffChar = serialutil.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()))
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.is_open:
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.name
try:
if port.upper().startswith('COM') and int(port[3:]) > 8:
port = '\\\\.\\' + port
except ValueError:
# for like COMnotanumber
pass
self._port_handle = 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._port_handle == win32.INVALID_HANDLE_VALUE:
self._port_handle = None # 'cause __del__ is called anyway
raise SerialException("could not open port {!r}: {!r}".format(
self.portstr, ctypes.WinError()))
try:
self._overlapped_read = win32.OVERLAPPED()
self._overlapped_read.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlapped_write = win32.OVERLAPPED()
#~ self._overlapped_write.hEvent = win32.CreateEvent(None, 1, 0, None)
self._overlapped_write.hEvent = win32.CreateEvent(None, 0, 0, None)
# Setup a 4k buffer
win32.SetupComm(self._port_handle, 4096, 4096)
# Save original timeout values:
self._orgTimeouts = win32.COMMTIMEOUTS()
win32.GetCommTimeouts(self._port_handle,
ctypes.byref(self._orgTimeouts))
self._reconfigure_port()
# Clear buffers:
# Remove anything that was there
win32.PurgeComm(
self._port_handle, 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._port_handle = None
raise
else:
self.is_open = True
def _reconfigurePort(self):
"""Set communication parameters on opened port."""
if self.fd is None:
raise SerialException("Can only operate on a valid port handle")
custom_baud = None
vmin = vtime = 0 # timeout is done via select
if self._interCharTimeout is not None:
vmin = 1
vtime = int(self._interCharTimeout * 10)
try:
iflag, oflag, cflag, lflag, ispeed, ospeed, cc = termios.tcgetattr(
self.fd)
# if a port is nonexistent but has a /dev file, it'll fail here
except termios.error as msg:
raise SerialException("Could not configure port: %s" % msg)
# set up raw mode / no echo / binary
cflag |= (TERMIOS.CLOCAL | TERMIOS.CREAD)
lflag &= ~(TERMIOS.ICANON | TERMIOS.ECHO | TERMIOS.ECHOE
| TERMIOS.ECHOK | TERMIOS.ECHONL | TERMIOS.ISIG
| TERMIOS.IEXTEN) # |TERMIOS.ECHOPRT
for flag in ('ECHOCTL', 'ECHOKE'): # netbsd workaround for Erk
if hasattr(TERMIOS, flag):
lflag &= ~getattr(TERMIOS, flag)
oflag &= ~(TERMIOS.OPOST)
iflag &= ~(TERMIOS.INLCR | TERMIOS.IGNCR | TERMIOS.ICRNL
| TERMIOS.IGNBRK)
if hasattr(TERMIOS, 'IUCLC'):
iflag &= ~TERMIOS.IUCLC
if hasattr(TERMIOS, 'PARMRK'):
iflag &= ~TERMIOS.PARMRK
# setup baudrate
try:
ispeed = ospeed = getattr(TERMIOS, 'B%s' % (self._baudrate))
except AttributeError:
try:
ispeed = ospeed = baudrate_constants[self._baudrate]
except KeyError:
#~ raise ValueError('Invalid baud rate: %r' % self._baudrate)
# may need custom baud rate, it isnt in our list.
ispeed = ospeed = getattr(TERMIOS, 'B38400')
custom_baud = int(self._baudrate) # store for later
# setup char len
cflag &= ~TERMIOS.CSIZE
if self._bytesize == 8:
cflag |= TERMIOS.CS8
elif self._bytesize == 7:
cflag |= TERMIOS.CS7
elif self._bytesize == 6:
cflag |= TERMIOS.CS6
elif self._bytesize == 5:
cflag |= TERMIOS.CS5
else:
raise ValueError('Invalid char len: %r' % self._bytesize)
# setup stopbits
if self._stopbits == STOPBITS_ONE:
cflag &= ~(TERMIOS.CSTOPB)
elif self._stopbits == STOPBITS_TWO:
cflag |= (TERMIOS.CSTOPB)
else:
raise ValueError('Invalid stopit specification: %r' %
self._stopbits)
# setup parity
iflag &= ~(TERMIOS.INPCK | TERMIOS.ISTRIP)
if self._parity == PARITY_NONE:
cflag &= ~(TERMIOS.PARENB | TERMIOS.PARODD)
elif self._parity == PARITY_EVEN:
cflag &= ~(TERMIOS.PARODD)
cflag |= (TERMIOS.PARENB)
elif self._parity == PARITY_ODD:
cflag |= (TERMIOS.PARENB | TERMIOS.PARODD)
else:
raise ValueError('Invalid parity: %r' % self._parity)
# setup flow control
# xonxoff
if hasattr(TERMIOS, 'IXANY'):
if self._xonxoff:
iflag |= (TERMIOS.IXON | TERMIOS.IXOFF) # |TERMIOS.IXANY)
else:
iflag &= ~(TERMIOS.IXON | TERMIOS.IXOFF | TERMIOS.IXANY)
else:
if self._xonxoff:
iflag |= (TERMIOS.IXON | TERMIOS.IXOFF)
else:
iflag &= ~(TERMIOS.IXON | TERMIOS.IXOFF)
# rtscts
if hasattr(TERMIOS, 'CRTSCTS'):
if self._rtscts:
cflag |= (TERMIOS.CRTSCTS)
else:
cflag &= ~(TERMIOS.CRTSCTS)
# try it with alternate constant name
elif hasattr(TERMIOS, 'CNEW_RTSCTS'):
if self._rtscts:
cflag |= (TERMIOS.CNEW_RTSCTS)
else:
cflag &= ~(TERMIOS.CNEW_RTSCTS)
# XXX should there be a warning if setting up rtscts (and xonxoff etc)
# fails??
# buffer
# vmin "minimal number of characters to be read. = for non blocking"
if vmin < 0 or vmin > 255:
raise ValueError('Invalid vmin: %r ' % vmin)
cc[TERMIOS.VMIN] = vmin
# vtime
if vtime < 0 or vtime > 255:
raise ValueError('Invalid vtime: %r' % vtime)
cc[TERMIOS.VTIME] = vtime
# activate settings
termios.tcsetattr(self.fd, TERMIOS.TCSANOW,
[iflag, oflag, cflag, lflag, ispeed, ospeed, cc])
# apply custom baud rate, if any
if custom_baud is not None:
import array
buf = array.array('i', [0] * 32)
# get serial_struct
FCNTL.ioctl(self.fd, TERMIOS.TIOCGSERIAL, buf)
# set custom divisor
buf[6] = buf[7] / custom_baud
# update flags
buf[4] &= ~ASYNC_SPD_MASK
buf[4] |= ASYNC_SPD_CUST
# set serial_struct
try:
res = FCNTL.ioctl(self.fd, TERMIOS.TIOCSSERIAL, buf)
except IOError:
raise ValueError('Failed to set custom baud rate: %r' %
self._baudrate)
def _reconfigure_port(self, force_update=False):
"""Set communication parameters on opened port."""
if self.fd is None:
raise SerialException(
"Can only operate on a valid file descriptor")
# if exclusive lock is requested, create it before we modify anything else
if self._exclusive is not None:
if self._exclusive:
try:
fcntl.flock(self.fd, fcntl.LOCK_EX | fcntl.LOCK_NB)
except IOError as msg:
raise SerialException(
msg.errno,
"Could not exclusively lock port {}: {}".format(
self._port, msg))
else:
fcntl.flock(self.fd, fcntl.LOCK_UN)
custom_baud = None
vmin = vtime = 0 # timeout is done via select
if self._inter_byte_timeout is not None:
vmin = 1
vtime = int(self._inter_byte_timeout * 10)
try:
orig_attr = termios.tcgetattr(self.fd)
iflag, oflag, cflag, lflag, ispeed, ospeed, cc = orig_attr
except termios.error as msg: # if a port is nonexistent but has a /dev file, it'll fail here
raise SerialException("Could not configure port: {}".format(msg))
# set up raw mode / no echo / binary
cflag |= (termios.CLOCAL | termios.CREAD)
lflag &= ~(termios.ICANON | termios.ECHO | termios.ECHOE
| termios.ECHOK | termios.ECHONL | termios.ISIG
| termios.IEXTEN) # |termios.ECHOPRT
for flag in ('ECHOCTL', 'ECHOKE'): # netbsd workaround for Erk
if hasattr(termios, flag):
lflag &= ~getattr(termios, flag)
oflag &= ~(termios.OPOST | termios.ONLCR | termios.OCRNL)
iflag &= ~(termios.INLCR | termios.IGNCR | termios.ICRNL
| termios.IGNBRK)
if hasattr(termios, 'IUCLC'):
iflag &= ~termios.IUCLC
if hasattr(termios, 'PARMRK'):
iflag &= ~termios.PARMRK
# setup baud rate
try:
ispeed = ospeed = getattr(termios, 'B{}'.format(self._baudrate))
except AttributeError:
try:
ispeed = ospeed = self.BAUDRATE_CONSTANTS[self._baudrate]
except KeyError:
#~ raise ValueError('Invalid baud rate: %r' % self._baudrate)
# may need custom baud rate, it isn't in our list.
ispeed = ospeed = getattr(termios, 'B38400')
try:
custom_baud = int(self._baudrate) # store for later
except ValueError:
raise ValueError('Invalid baud rate: {!r}'.format(
self._baudrate))
else:
if custom_baud < 0:
raise ValueError('Invalid baud rate: {!r}'.format(
self._baudrate))
# setup char len
cflag &= ~termios.CSIZE
if self._bytesize == 8:
cflag |= termios.CS8
elif self._bytesize == 7:
cflag |= termios.CS7
elif self._bytesize == 6:
cflag |= termios.CS6
elif self._bytesize == 5:
cflag |= termios.CS5
else:
raise ValueError('Invalid char len: {!r}'.format(self._bytesize))
# setup stop bits
if self._stopbits == serialutil.STOPBITS_ONE:
cflag &= ~(termios.CSTOPB)
elif self._stopbits == serialutil.STOPBITS_ONE_POINT_FIVE:
cflag |= (termios.CSTOPB
) # XXX same as TWO.. there is no POSIX support for 1.5
elif self._stopbits == serialutil.STOPBITS_TWO:
cflag |= (termios.CSTOPB)
else:
raise ValueError('Invalid stop bit specification: {!r}'.format(
self._stopbits))
# setup parity
iflag &= ~(termios.INPCK | termios.ISTRIP)
if self._parity == serialutil.PARITY_NONE:
cflag &= ~(termios.PARENB | termios.PARODD | CMSPAR)
elif self._parity == serialutil.PARITY_EVEN:
cflag &= ~(termios.PARODD | CMSPAR)
cflag |= (termios.PARENB)
elif self._parity == serialutil.PARITY_ODD:
cflag &= ~CMSPAR
cflag |= (termios.PARENB | termios.PARODD)
elif self._parity == serialutil.PARITY_MARK and CMSPAR:
cflag |= (termios.PARENB | CMSPAR | termios.PARODD)
elif self._parity == serialutil.PARITY_SPACE and CMSPAR:
cflag |= (termios.PARENB | CMSPAR)
cflag &= ~(termios.PARODD)
else:
raise ValueError('Invalid parity: {!r}'.format(self._parity))
# setup flow control
# xonxoff
if hasattr(termios, 'IXANY'):
if self._xonxoff:
iflag |= (termios.IXON | termios.IXOFF) # |termios.IXANY)
else:
iflag &= ~(termios.IXON | termios.IXOFF | termios.IXANY)
else:
if self._xonxoff:
iflag |= (termios.IXON | termios.IXOFF)
else:
iflag &= ~(termios.IXON | termios.IXOFF)
# rtscts
if hasattr(termios, 'CRTSCTS'):
if self._rtscts:
cflag |= (termios.CRTSCTS)
else:
cflag &= ~(termios.CRTSCTS)
elif hasattr(termios,
'CNEW_RTSCTS'): # try it with alternate constant name
if self._rtscts:
cflag |= (termios.CNEW_RTSCTS)
else:
cflag &= ~(termios.CNEW_RTSCTS)
# XXX should there be a warning if setting up rtscts (and xonxoff etc) fails??
# buffer
# vmin "minimal number of characters to be read. 0 for non blocking"
if vmin < 0 or vmin > 255:
raise ValueError('Invalid vmin: {!r}'.format(vmin))
cc[termios.VMIN] = vmin
# vtime
if vtime < 0 or vtime > 255:
raise ValueError('Invalid vtime: {!r}'.format(vtime))
cc[termios.VTIME] = vtime
# activate settings
if force_update or [iflag, oflag, cflag, lflag, ispeed, ospeed, cc
] != orig_attr:
termios.tcsetattr(self.fd, termios.TCSANOW,
[iflag, oflag, cflag, lflag, ispeed, ospeed, cc])
# apply custom baud rate, if any
if custom_baud is not None:
self._set_special_baudrate(custom_baud)
if self._rs485_mode is not None:
self._set_rs485_mode(self._rs485_mode)