#!/usr/bin/env python
#Python Serial Port Extension for Win32, Linux, BSD, Jython
#module for serial IO for POSIX compatible systems, like Linux
#see __init__.py
#
#(C) 2001-2003 Chris Liechti <cliechti@gmx.net>
# this is distributed under a free software license, see license.txt
#
#parts based on code from Grant B. Edwards <grante@visi.com>:
# ftp://ftp.visi.com/users/grante/python/PosixSerial.py
# references: http://www.easysw.com/~mike/serial/serial.html
import sys, os, fcntl, termios, struct, select
from serialutil import *
VERSION = "$Revision: 1.4 $".split()[1] #extract CVS version
#Do check the Python version as some constants have moved.
if (sys.hexversion < 0x020100f0):
import TERMIOS
else:
TERMIOS = termios
if (sys.hexversion < 0x020200f0):
import FCNTL
else:
FCNTL = fcntl
#try to detect the os so that a device can be selected...
plat = sys.platform.lower()
if plat[:5] == 'linux': #Linux (confirmed)
def device(port):
return '/dev/ttyS%d' % port
elif plat == 'cygwin': #cywin/win32 (confirmed)
def device(port):
return '/dev/com%d' % (port + 1)
elif plat == 'openbsd3': #BSD (confirmed)
def device(port):
return '/dev/ttyp%d' % port
elif plat[:3] == 'bsd' or \
plat[:6] == 'netbsd' or \
plat[:7] == 'freebsd' or \
plat[:7] == 'openbsd' or \
plat[:6] == 'darwin': #BSD (confirmed for freebsd4: cuaa%d)
def device(port):
return '/dev/cuaa%d' % port
elif plat[:4] == 'irix': #IRIX (not tested)
def device(port):
return '/dev/ttyf%d' % port
elif plat[:2] == 'hp': #HP-UX (not tested)
def device(port):
return '/dev/tty%dp0' % (port+1)
elif plat[:5] == 'sunos': #Solaris/SunOS (confirmed)
def device(port):
return '/dev/tty%c' % (ord('a')+port)
else:
#platform detection has failed...
info = "sys.platform = %r\nos.name = %r\nserialposix.py version = %s" % (sys.platform, os.name, VERSION)
print """send this information to the author of the pyserial:
%s
also add the device name of the serial port and where the
counting starts for the first serial port.
e.g. 'first serial port: /dev/ttyS0'
and with a bit luck you can get this module running...
"""
#no exception, just continue with a brave attempt to build a device name
#even if the device name is not correct for the platform it has chances
#to work using a string with the real device name as port paramter.
def device(portum):
return '/dev/ttyS%d' % portnum
#~ raise Exception, "this module does not run on this platform, sorry."
#whats up with "aix", "beos", "sco", ....
#they should work, just need to know the device names.
# construct dictionaries for baud rate lookups
baudEnumToInt = {}
baudIntToEnum = {}
for rate in (0,50,75,110,134,150,200,300,600,1200,1800,2400,4800,9600,
19200,38400,57600,115200,230400,460800,500000,576000,921600,
1000000,1152000,1500000,2000000,2500000,3000000,3500000,4000000
):
try:
i = eval('TERMIOS.B'+str(rate))
baudEnumToInt[i]=rate
baudIntToEnum[rate] = i
except:
pass
#load some constants for later use.
#try to use values from TERMIOS, use defaults from linux otherwise
TIOCMGET = hasattr(TERMIOS, 'TIOCMGET') and TERMIOS.TIOCMGET or 0x5415
TIOCMBIS = hasattr(TERMIOS, 'TIOCMBIS') and TERMIOS.TIOCMBIS or 0x5416
TIOCMBIC = hasattr(TERMIOS, 'TIOCMBIC') and TERMIOS.TIOCMBIC or 0x5417
TIOCMSET = hasattr(TERMIOS, 'TIOCMSET') and TERMIOS.TIOCMSET or 0x5418
#TIOCM_LE = hasattr(TERMIOS, 'TIOCM_LE') and TERMIOS.TIOCM_LE or 0x001
TIOCM_DTR = hasattr(TERMIOS, 'TIOCM_DTR') and TERMIOS.TIOCM_DTR or 0x002
TIOCM_RTS = hasattr(TERMIOS, 'TIOCM_RTS') and TERMIOS.TIOCM_RTS or 0x004
#TIOCM_ST = hasattr(TERMIOS, 'TIOCM_ST') and TERMIOS.TIOCM_ST or 0x008
#TIOCM_SR = hasattr(TERMIOS, 'TIOCM_SR') and TERMIOS.TIOCM_SR or 0x010
TIOCM_CTS = hasattr(TERMIOS, 'TIOCM_CTS') and TERMIOS.TIOCM_CTS or 0x020
TIOCM_CAR = hasattr(TERMIOS, 'TIOCM_CAR') and TERMIOS.TIOCM_CAR or 0x040
TIOCM_RNG = hasattr(TERMIOS, 'TIOCM_RNG') and TERMIOS.TIOCM_RNG or 0x080
TIOCM_DSR = hasattr(TERMIOS, 'TIOCM_DSR') and TERMIOS.TIOCM_DSR or 0x100
TIOCM_CD = hasattr(TERMIOS, 'TIOCM_CD') and TERMIOS.TIOCM_CD or TIOCM_CAR
TIOCM_RI = hasattr(TERMIOS, 'TIOCM_RI') and TERMIOS.TIOCM_RI or TIOCM_RNG
#TIOCM_OUT1 = hasattr(TERMIOS, 'TIOCM_OUT1') and TERMIOS.TIOCM_OUT1 or 0x2000
#TIOCM_OUT2 = hasattr(TERMIOS, 'TIOCM_OUT2') and TERMIOS.TIOCM_OUT2 or 0x4000
TIOCINQ = hasattr(TERMIOS, 'FIONREAD') and TERMIOS.FIONREAD or 0x541B
TIOCM_zero_str = struct.pack('I', 0)
TIOCM_RTS_str = struct.pack('I', TIOCM_RTS)
TIOCM_DTR_str = struct.pack('I', TIOCM_DTR)
class Serial(SerialBase):
"""Serial port class POSIX implementation. Serial port configuration is
done with termios and fcntl. Runs on Linux and many other Un*x like
systems."""
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, msg:
self.fd = None
raise SerialException("Could not open port: %s" % msg)
fcntl.fcntl(self.fd, FCNTL.F_SETFL, 0) #set blocking
self._reconfigurePort()
self._isOpen = True
def _reconfigurePort(self):
"""Set commuication parameters on opened port."""
if not self.fd:
raise SerialException("Can only operate on a valid port handle")
vmin = vtime = 0 #timeout is done via select
try:
iflag, oflag, cflag, lflag, ispeed, ospeed, cc = termios.tcgetattr(self.fd)
except termios.error, msg: #if a port is nonexistent but has a /dev file, it'll fail here
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.ECHOCTL|TERMIOS.ECHOKE|TERMIOS.ISIG|TERMIOS.IEXTEN) #|TERMIOS.ECHOPRT
oflag &= ~(TERMIOS.OPOST)
if hasattr(TERMIOS, 'IUCLC'):
iflag &= ~(TERMIOS.INLCR|TERMIOS.IGNCR|TERMIOS.ICRNL|TERMIOS.IUCLC|TERMIOS.IGNBRK)
else:
iflag &= ~(TERMIOS.INLCR|TERMIOS.IGNCR|TERMIOS.ICRNL|TERMIOS.IGNBRK)
#setup baudrate
try:
ispeed = ospeed = baudIntToEnum[self._baudrate]
except:
raise ValueError('Invalid baud rate: %r' % 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' % 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)
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. = 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])
def close(self):
"""Close port"""
if self._isOpen:
if self.fd:
os.close(self.fd)
self.fd = None
self._isOpen = False
def makeDeviceName(self, port):
return device(port)
# - - - - - - - - - - - - - - - - - - - - - - - -
def inWaiting(self):
"""Return the number of characters currently in the input buffer."""
#~ s = fcntl.ioctl(self.fd, TERMIOS.FIONREAD, TIOCM_zero_str)
s = fcntl.ioctl(self.fd, TIOCINQ, TIOCM_zero_str)
return struct.unpack('I',s)[0]
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.fd: raise portNotOpenError
read = ''
inp = None
if size > 0:
while len(read) < size:
#print "\tread(): size",size, "have", len(read) #debug
ready,_,_ = select.select([self.fd],[],[], self.timeout)
if not ready:
break #timeout
buf = os.read(self.fd, size-len(read))
read = read + buf
if self.timeout >= 0 and not buf:
break #early abort on timeout
return read
def write(self, data):
"""Output the given string over the serial port."""
if not self.fd: raise portNotOpenError
t = len(data)
d = data
while t>0:
n = os.write(self.fd, d)
d = d[n:]
t = t - n
def flush(self):
"""Flush of file like objects. In this case, wait until all data
is written."""
self.drainOutput()
def flushInput(self):
"""Clear input buffer, discarding all that is in the buffer."""
if not self.fd:
raise portNotOpenError
termios.tcflush(self.fd, TERMIOS.TCIFLUSH)
def flushOutput(self):
"""Clear output buffer, aborting the current output and
discarding all that is in the buffer."""
if not self.fd:
raise portNotOpenError
termios.tcflush(self.fd, TERMIOS.TCOFLUSH)
def sendBreak(self):
"""Send break condition."""
if not self.fd:
raise portNotOpenError
termios.tcsendbreak(self.fd, 0)
def setRTS(self,on=1):
"""Set terminal status line: Request To Send"""
if not self.fd: raise portNotOpenError
if on:
fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_RTS_str)
else:
fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_RTS_str)
def setDTR(self,on=1):
"""Set terminal status line: Data Terminal Ready"""
if not self.fd: raise portNotOpenError
if on:
fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_DTR_str)
else:
fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_DTR_str)
def getCTS(self):
"""Read terminal status line: Clear To Send"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_CTS != 0
def getDSR(self):
"""Read terminal status line: Data Set Ready"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_DSR != 0
def getRI(self):
"""Read terminal status line: Ring Indicator"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_RI != 0
def getCD(self):
"""Read terminal status line: Carrier Detect"""
if not self.fd: raise portNotOpenError
s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str)
return struct.unpack('I',s)[0] & TIOCM_CD != 0
# - - platform specific - - - -
def drainOutput(self):
"""internal - not portable!"""
if not self.fd: raise portNotOpenError
termios.tcdrain(self.fd)
def nonblocking(self):
"""internal - not portable!"""
if not self.fd:
raise portNotOpenError
fcntl.fcntl(self.fd, FCNTL.F_SETFL, FCNTL.O_NONBLOCK)
if __name__ == '__main__':
s = Serial(0,
baudrate=19200, #baudrate
bytesize=EIGHTBITS, #number of databits
parity=PARITY_EVEN, #enable parity checking
stopbits=STOPBITS_ONE, #number of stopbits
timeout=3, #set a timeout value, None for waiting forever
xonxoff=0, #enable software flow control
rtscts=0, #enable RTS/CTS flow control
)
s.setRTS(1)
s.setDTR(1)
s.flushInput()
s.flushOutput()
s.write('hello')
print repr(s.read(5))
print s.inWaiting()
del s
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