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#! /usr/bin/python
#Python Serial Port Extension for Win32, Linux, BSD, Jython
#see __init__.py
#
#(C) 2001-2003 Chris Liechti <cliechti@gmx.net>
# this is distributed under a free software license, see license.txt
PARITY_NONE, PARITY_EVEN, PARITY_ODD = 'N', 'E', 'O'
STOPBITS_ONE, STOPBITS_TWO = (1, 2)
FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS = (5,6,7,8)
PARITY_NAMES = {
PARITY_NONE: 'None',
PARITY_EVEN: 'Even',
PARITY_ODD: 'Odd',
}
XON = chr(17)
XOFF = chr(19)
#Python < 2.2.3 compatibility
try:
True
except:
True = 1
False = not True
class SerialException(Exception):
"""Base class for serial port related exceptions."""
portNotOpenError = SerialException('Port not open')
class SerialTimeoutException(SerialException):
"""Write timeouts give an exception"""
writeTimeoutError = SerialTimeoutException("Write timeout")
class FileLike(object):
"""An abstract file like class.
This class implements readline and readlines based on read and
writelines based on write.
This class is used to provide the above functions for to Serial
port objects.
Note that when the serial port was opened with _NO_ timeout that
readline blocks until it sees a newline (or the specified size is
reached) and that readlines would never return and therefore
refuses to work (it raises an exception in this case)!
"""
def read(self, size): raise NotImplementedError
def write(self, s): raise NotImplementedError
def readline(self, size=None, eol='\n'):
"""read a line which is terminated with end-of-line (eol) character
('\n' by default) or until timeout"""
line = ''
while 1:
c = self.read(1)
if c:
line += c #not very efficient but lines are usually not that long
if c == eol:
break
if size is not None and len(line) >= size:
break
else:
break
return line
def readlines(self, sizehint=None, eol='\n'):
"""read a list of lines, until timeout
sizehint is ignored"""
if self.timeout is None:
raise ValueError, "Serial port MUST have enabled timeout for this function!"
lines = []
while 1:
line = self.readline(eol=eol)
if line:
lines.append(line)
if line[-1] != eol: #was the line received with a timeout?
break
else:
break
return lines
def xreadlines(self, sizehint=None):
"""just call readlines - here for compatibility"""
return self.readlines()
def writelines(self, sequence):
for line in sequence:
self.write(line)
def flush(self):
"""flush of file like objects"""
pass
# iterator for e.g. "for line in Serial(0): ..." usage
def next(self):
line = self.readline()
if not line: raise StopIteration
return line
def __iter__(self):
return self
class SerialBase(FileLike):
"""Serial port base class. Provides __init__ function and properties to
get/set port settings."""
#default values, may be overriden in subclasses that do not support all values
BAUDRATES = (50,75,110,134,150,200,300,600,1200,1800,2400,4800,9600,
19200,38400,57600,115200,230400,460800,500000,576000,921600,
1000000,1152000,1500000,2000000,2500000,3000000,3500000,4000000)
BYTESIZES = (FIVEBITS, SIXBITS, SEVENBITS, EIGHTBITS)
PARITIES = (PARITY_NONE, PARITY_EVEN, PARITY_ODD)
STOPBITS = (STOPBITS_ONE, STOPBITS_TWO)
def __init__(self,
port = None, #number of device, numbering starts at
#zero. if everything fails, the user
#can specify a device string, note
#that this isn't portable anymore
#port will be opened if one is specified
baudrate=9600, #baudrate
bytesize=EIGHTBITS, #number of databits
parity=PARITY_NONE, #enable parity checking
stopbits=STOPBITS_ONE, #number of stopbits
timeout=None, #set a timeout value, None to wait forever
xonxoff=0, #enable software flow control
rtscts=0, #enable RTS/CTS flow control
writeTimeout=None, #set a timeout for writes
dsrdtr=None, #None: use rtscts setting, dsrdtr override if true or false
):
"""Initialize comm port object. If a port is given, then the port will be
opened immediately. Otherwise a Serial port object in closed state
is returned."""
self._isOpen = False
self._port = None #correct value is assigned below trough properties
self._baudrate = None #correct value is assigned below trough properties
self._bytesize = None #correct value is assigned below trough properties
self._parity = None #correct value is assigned below trough properties
self._stopbits = None #correct value is assigned below trough properties
self._timeout = None #correct value is assigned below trough properties
self._writeTimeout = None #correct value is assigned below trough properties
self._xonxoff = None #correct value is assigned below trough properties
self._rtscts = None #correct value is assigned below trough properties
self._dsrdtr = None #correct value is assigned below trough properties
#assign values using get/set methods using the properties feature
self.port = port
self.baudrate = baudrate
self.bytesize = bytesize
self.parity = parity
self.stopbits = stopbits
self.timeout = timeout
self.writeTimeout = writeTimeout
self.xonxoff = xonxoff
self.rtscts = rtscts
self.dsrdtr = dsrdtr
if port is not None:
self.open()
def isOpen(self):
"""Check if the port is opened."""
return self._isOpen
# - - - - - - - - - - - - - - - - - - - - - - - -
#TODO: these are not realy needed as the is the BAUDRATES etc attribute...
#maybe i remove them before the final release...
def getSupportedBaudrates(self):
return [(str(b), b) for b in self.BAUDRATES]
def getSupportedByteSizes(self):
return [(str(b), b) for b in self.BYTESIZES]
def getSupportedStopbits(self):
return [(str(b), b) for b in self.STOPBITS]
def getSupportedParities(self):
return [(PARITY_NAMES[b], b) for b in self.PARITIES]
# - - - - - - - - - - - - - - - - - - - - - - - -
def setPort(self, port):
"""Change the port. The attribute portstr is set to a string that
contains the name of the port."""
was_open = self._isOpen
if was_open: self.close()
if port is not None:
if type(port) in [type(''), type(u'')]: #strings are taken directly
self.portstr = port
else:
self.portstr = self.makeDeviceName(port)
else:
self.portstr = None
self._port = port
if was_open: self.open()
def getPort(self):
"""Get the current port setting. The value that was passed on init or using
setPort() is passed back. See also the attribute portstr which contains
the name of the port as a string."""
return self._port
port = property(getPort, setPort, doc="Port setting")
def setBaudrate(self, baudrate):
"""Change baudrate. It raises a ValueError if the port is open and the
baudrate is not possible. If the port is closed, then tha value is
accepted and the exception is raised when the port is opened."""
#~ if baudrate not in self.BAUDRATES: raise ValueError("Not a valid baudrate: %r" % baudrate)
try:
self._baudrate = int(baudrate)
except TypeError:
raise ValueError("Not a valid baudrate: %r" % (baudrate,))
else:
if self._isOpen: self._reconfigurePort()
def getBaudrate(self):
"""Get the current baudrate setting."""
return self._baudrate
baudrate = property(getBaudrate, setBaudrate, doc="Baudrate setting")
def setByteSize(self, bytesize):
"""Change byte size."""
if bytesize not in self.BYTESIZES: raise ValueError("Not a valid byte size: %r" % (bytesize,))
self._bytesize = bytesize
if self._isOpen: self._reconfigurePort()
def getByteSize(self):
"""Get the current byte size setting."""
return self._bytesize
bytesize = property(getByteSize, setByteSize, doc="Byte size setting")
def setParity(self, parity):
"""Change parity setting."""
if parity not in self.PARITIES: raise ValueError("Not a valid parity: %r" % (parity,))
self._parity = parity
if self._isOpen: self._reconfigurePort()
def getParity(self):
"""Get the current parity setting."""
return self._parity
parity = property(getParity, setParity, doc="Parity setting")
def setStopbits(self, stopbits):
"""Change stopbits size."""
if stopbits not in self.STOPBITS: raise ValueError("Not a valid stopbit size: %r" % (stopbits,))
self._stopbits = stopbits
if self._isOpen: self._reconfigurePort()
def getStopbits(self):
"""Get the current stopbits setting."""
return self._stopbits
stopbits = property(getStopbits, setStopbits, doc="Stopbits setting")
def setTimeout(self, timeout):
"""Change timeout setting."""
if timeout is not None:
if timeout < 0: raise ValueError("Not a valid timeout: %r" % (timeout,))
try:
timeout + 1 #test if it's a number, will throw a TypeError if not...
except TypeError:
raise ValueError("Not a valid timeout: %r" % (timeout,))
self._timeout = timeout
if self._isOpen: self._reconfigurePort()
def getTimeout(self):
"""Get the current timeout setting."""
return self._timeout
timeout = property(getTimeout, setTimeout, doc="Timeout setting for read()")
def setWriteTimeout(self, timeout):
"""Change timeout setting."""
if timeout is not None:
if timeout < 0: raise ValueError("Not a valid timeout: %r" % (timeout,))
try:
timeout + 1 #test if it's a number, will throw a TypeError if not...
except TypeError:
raise ValueError("Not a valid timeout: %r" % timeout)
self._writeTimeout = timeout
if self._isOpen: self._reconfigurePort()
def getWriteTimeout(self):
"""Get the current timeout setting."""
return self._writeTimeout
writeTimeout = property(getWriteTimeout, setWriteTimeout, doc="Timeout setting for write()")
def setXonXoff(self, xonxoff):
"""Change XonXoff setting."""
self._xonxoff = xonxoff
if self._isOpen: self._reconfigurePort()
def getXonXoff(self):
"""Get the current XonXoff setting."""
return self._xonxoff
xonxoff = property(getXonXoff, setXonXoff, doc="Xon/Xoff setting")
def setRtsCts(self, rtscts):
"""Change RtsCts flow control setting."""
self._rtscts = rtscts
if self._isOpen: self._reconfigurePort()
def getRtsCts(self):
"""Get the current RtsCts flow control setting."""
return self._rtscts
rtscts = property(getRtsCts, setRtsCts, doc="RTS/CTS flow control setting")
def setDsrDtr(self, dsrdtr=None):
"""Change DsrDtr flow control setting."""
if dsrdtr is None:
#if not set, keep backwards compatibility and follow rtscts setting
self._dsrdtr = self._rtscts
else:
#if defined independently, follow its value
self._dsrdtr = dsrdtr
if self._isOpen: self._reconfigurePort()
def getDsrDtr(self):
"""Get the current DsrDtr flow control setting."""
return self._dsrdtr
dsrdtr = property(getDsrDtr, setDsrDtr, "DSR/DTR flow control setting")
# - - - - - - - - - - - - - - - - - - - - - - - -
def __repr__(self):
"""String representation of the current port settings and its state."""
return "%s<id=0x%x, open=%s>(port=%r, baudrate=%r, bytesize=%r, parity=%r, stopbits=%r, timeout=%r, xonxoff=%r, rtscts=%r, dsrdtr=%r)" % (
self.__class__.__name__,
id(self),
self._isOpen,
self.portstr,
self.baudrate,
self.bytesize,
self.parity,
self.stopbits,
self.timeout,
self.xonxoff,
self.rtscts,
self.dsrdtr,
)
if __name__ == '__main__':
s = SerialBase()
print s.portstr
print s.getSupportedBaudrates()
print s.getSupportedByteSizes()
print s.getSupportedParities()
print s.getSupportedStopbits()
print s
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