diff options
Diffstat (limited to 'lib/python2.7/site-packages/serial/serialposix.py')
| -rw-r--r-- | lib/python2.7/site-packages/serial/serialposix.py | 703 |
1 files changed, 0 insertions, 703 deletions
diff --git a/lib/python2.7/site-packages/serial/serialposix.py b/lib/python2.7/site-packages/serial/serialposix.py deleted file mode 100644 index b9b4b28..0000000 --- a/lib/python2.7/site-packages/serial/serialposix.py +++ /dev/null @@ -1,703 +0,0 @@ -#!/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) 2001-2010 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, errno, time -from serial.serialutil import * - -# 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... -# this code block should supply a device() and set_special_baudrate() function -# for the platform -plat = sys.platform.lower() - -if plat[:5] == 'linux': # Linux (confirmed) - - def device(port): - return '/dev/ttyS%d' % port - - TCGETS2 = 0x802C542A - TCSETS2 = 0x402C542B - BOTHER = 0o010000 - - def set_special_baudrate(port, baudrate): - # right size is 44 on x86_64, allow for some growth - import array - buf = array.array('i', [0] * 64) - - try: - # get serial_struct - FCNTL.ioctl(port.fd, TCGETS2, buf) - # set custom speed - buf[2] &= ~TERMIOS.CBAUD - buf[2] |= BOTHER - buf[9] = buf[10] = baudrate - - # set serial_struct - res = FCNTL.ioctl(port.fd, TCSETS2, buf) - except IOError, e: - raise ValueError('Failed to set custom baud rate (%s): %s' % (baudrate, e)) - - baudrate_constants = { - 0: 0000000, # hang up - 50: 0000001, - 75: 0000002, - 110: 0000003, - 134: 0000004, - 150: 0000005, - 200: 0000006, - 300: 0000007, - 600: 0000010, - 1200: 0000011, - 1800: 0000012, - 2400: 0000013, - 4800: 0000014, - 9600: 0000015, - 19200: 0000016, - 38400: 0000017, - 57600: 0010001, - 115200: 0010002, - 230400: 0010003, - 460800: 0010004, - 500000: 0010005, - 576000: 0010006, - 921600: 0010007, - 1000000: 0010010, - 1152000: 0010011, - 1500000: 0010012, - 2000000: 0010013, - 2500000: 0010014, - 3000000: 0010015, - 3500000: 0010016, - 4000000: 0010017 - } - -elif plat == 'cygwin': # cygwin/win32 (confirmed) - - def device(port): - return '/dev/com%d' % (port + 1) - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = { - 128000: 0x01003, - 256000: 0x01005, - 500000: 0x01007, - 576000: 0x01008, - 921600: 0x01009, - 1000000: 0x0100a, - 1152000: 0x0100b, - 1500000: 0x0100c, - 2000000: 0x0100d, - 2500000: 0x0100e, - 3000000: 0x0100f - } - -elif plat[:7] == 'openbsd': # OpenBSD - - def device(port): - return '/dev/cua%02d' % port - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = {} - -elif plat[:3] == 'bsd' or \ - plat[:7] == 'freebsd': - - def device(port): - return '/dev/cuad%d' % port - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = {} - -elif plat[:6] == 'darwin': # OS X - - version = os.uname()[2].split('.') - # Tiger or above can support arbitrary serial speeds - if int(version[0]) >= 8: - def set_special_baudrate(port, baudrate): - # use IOKit-specific call to set up high speeds - import array, fcntl - buf = array.array('i', [baudrate]) - IOSSIOSPEED = 0x80045402 #_IOW('T', 2, speed_t) - fcntl.ioctl(port.fd, IOSSIOSPEED, buf, 1) - else: # version < 8 - def set_special_baudrate(port, baudrate): - raise ValueError("baud rate not supported") - - def device(port): - return '/dev/cuad%d' % port - - baudrate_constants = {} - - -elif plat[:6] == 'netbsd': # NetBSD 1.6 testing by Erk - - def device(port): - return '/dev/dty%02d' % port - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = {} - -elif plat[:4] == 'irix': # IRIX (partially tested) - - def device(port): - return '/dev/ttyf%d' % (port+1) #XXX different device names depending on flow control - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = {} - -elif plat[:2] == 'hp': # HP-UX (not tested) - - def device(port): - return '/dev/tty%dp0' % (port+1) - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = {} - -elif plat[:5] == 'sunos': # Solaris/SunOS (confirmed) - - def device(port): - return '/dev/tty%c' % (ord('a')+port) - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = {} - -elif plat[:3] == 'aix': # AIX - - def device(port): - return '/dev/tty%d' % (port) - - def set_special_baudrate(port, baudrate): - raise ValueError("sorry don't know how to handle non standard baud rate on this platform") - - baudrate_constants = {} - -else: - # platform detection has failed... - sys.stderr.write("""\ -don't know how to number ttys on this system. -! Use an explicit path (eg /dev/ttyS1) or send this information to -! the author of this module: - -sys.platform = %r -os.name = %r -serialposix.py version = %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... -""" % (sys.platform, os.name, VERSION)) - # 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 parameter. - def device(portum): - return '/dev/ttyS%d' % portnum - def set_special_baudrate(port, baudrate): - raise SerialException("sorry don't know how to handle non standard baud rate on this platform") - baudrate_constants = {} - #~ raise Exception, "this module does not run on this platform, sorry." - -# whats up with "aix", "beos", .... -# they should work, just need to know the device names. - - -# 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 -if hasattr(TERMIOS, 'TIOCINQ'): - TIOCINQ = TERMIOS.TIOCINQ -else: - TIOCINQ = hasattr(TERMIOS, 'FIONREAD') and TERMIOS.FIONREAD or 0x541B -TIOCOUTQ = hasattr(TERMIOS, 'TIOCOUTQ') and TERMIOS.TIOCOUTQ or 0x5411 - -TIOCM_zero_str = struct.pack('I', 0) -TIOCM_RTS_str = struct.pack('I', TIOCM_RTS) -TIOCM_DTR_str = struct.pack('I', TIOCM_DTR) - -TIOCSBRK = hasattr(TERMIOS, 'TIOCSBRK') and TERMIOS.TIOCSBRK or 0x5427 -TIOCCBRK = hasattr(TERMIOS, 'TIOCCBRK') and TERMIOS.TIOCCBRK or 0x5428 - - -class PosixSerial(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.") - if self._isOpen: - 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 IOError, msg: - self.fd = None - raise SerialException(msg.errno, "could not open port %s: %s" % (self._port, msg)) - #~ fcntl.fcntl(self.fd, FCNTL.F_SETFL, 0) # set blocking - - try: - self._reconfigurePort() - 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._isOpen = True - self.flushInput() - - - def _reconfigurePort(self): - """Set communication parameters on opened port.""" - if self.fd is None: - raise SerialException("Can only operate on a valid file descriptor") - 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: - orig_attr = termios.tcgetattr(self.fd) - iflag, oflag, cflag, lflag, ispeed, ospeed, cc = orig_attr - 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.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 baud rate - 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 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' % self._baudrate) - else: - if custom_baud < 0: - 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_ONE_POINT_FIVE: - cflag |= (TERMIOS.CSTOPB) # XXX same as TWO.. there is no POSIX support for 1.5 - elif self._stopbits == STOPBITS_TWO: - cflag |= (TERMIOS.CSTOPB) - else: - raise ValueError('Invalid stop bit 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 - if [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: - set_special_baudrate(self, custom_baud) - - def close(self): - """Close port""" - if self._isOpen: - if self.fd is not None: - 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] - - # select based implementation, proved to work on many systems - 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._isOpen: raise portNotOpenError - read = bytearray() - while len(read) < size: - try: - ready,_,_ = select.select([self.fd],[],[], self._timeout) - # 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 select.error, e: - # ignore EAGAIN errors. all other errors are shown - # see also http://www.python.org/dev/peps/pep-3151/#select - if e[0] != errno.EAGAIN: - raise SerialException('read failed: %s' % (e,)) - except OSError, e: - # ignore EAGAIN errors. all other errors are shown - if e.errno != errno.EAGAIN: - raise SerialException('read failed: %s' % (e,)) - return bytes(read) - - def write(self, data): - """Output the given string over the serial port.""" - if not self._isOpen: raise portNotOpenError - d = to_bytes(data) - tx_len = len(d) - if self._writeTimeout is not None and self._writeTimeout > 0: - timeout = time.time() + self._writeTimeout - else: - timeout = None - while tx_len > 0: - try: - n = os.write(self.fd, d) - if timeout: - # when timeout is set, use select to wait for being ready - # with the time left as timeout - timeleft = timeout - time.time() - if timeleft < 0: - raise writeTimeoutError - _, ready, _ = select.select([], [self.fd], [], timeleft) - if not ready: - raise writeTimeoutError - else: - # wait for write operation - _, ready, _ = select.select([], [self.fd], [], None) - if not ready: - raise SerialException('write failed (select)') - d = d[n:] - tx_len -= n - except OSError, v: - if v.errno != errno.EAGAIN: - raise SerialException('write failed: %s' % (v,)) - return len(data) - - 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._isOpen: 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._isOpen: raise portNotOpenError - termios.tcflush(self.fd, TERMIOS.TCOFLUSH) - - def sendBreak(self, duration=0.25): - """Send break condition. Timed, returns to idle state after given duration.""" - if not self._isOpen: raise portNotOpenError - termios.tcsendbreak(self.fd, int(duration/0.25)) - - def setBreak(self, level=1): - """Set break: Controls TXD. When active, no transmitting is possible.""" - if self.fd is None: raise portNotOpenError - if level: - fcntl.ioctl(self.fd, TIOCSBRK) - else: - fcntl.ioctl(self.fd, TIOCCBRK) - - def setRTS(self, level=1): - """Set terminal status line: Request To Send""" - if not self._isOpen: raise portNotOpenError - if level: - fcntl.ioctl(self.fd, TIOCMBIS, TIOCM_RTS_str) - else: - fcntl.ioctl(self.fd, TIOCMBIC, TIOCM_RTS_str) - - def setDTR(self, level=1): - """Set terminal status line: Data Terminal Ready""" - if not self._isOpen: raise portNotOpenError - if level: - 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._isOpen: 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._isOpen: 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._isOpen: 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._isOpen: raise portNotOpenError - s = fcntl.ioctl(self.fd, TIOCMGET, TIOCM_zero_str) - return struct.unpack('I',s)[0] & TIOCM_CD != 0 - - # - - platform specific - - - - - - def outWaiting(self): - """Return the number of characters currently in the output buffer.""" - #~ s = fcntl.ioctl(self.fd, TERMIOS.FIONREAD, TIOCM_zero_str) - s = fcntl.ioctl(self.fd, TIOCOUTQ, TIOCM_zero_str) - return struct.unpack('I',s)[0] - - def drainOutput(self): - """internal - not portable!""" - if not self._isOpen: raise portNotOpenError - termios.tcdrain(self.fd) - - def nonblocking(self): - """internal - not portable!""" - if not self._isOpen: raise portNotOpenError - fcntl.fcntl(self.fd, FCNTL.F_SETFL, os.O_NONBLOCK) - - def fileno(self): - """\ - For easier use of the serial port instance with select. - WARNING: this function is not portable to different platforms! - """ - if not self._isOpen: raise portNotOpenError - return self.fd - - def setXON(self, level=True): - """\ - Manually control flow - when software flow control is enabled. - This will send XON (true) and XOFF (false) to the other device. - WARNING: this function is not portable to different platforms! - """ - if not self.hComPort: raise portNotOpenError - if enable: - termios.tcflow(self.fd, TERMIOS.TCION) - else: - termios.tcflow(self.fd, TERMIOS.TCIOFF) - - def flowControlOut(self, enable): - """\ - Manually control flow of outgoing data - when hardware or software flow - control is enabled. - WARNING: this function is not portable to different platforms! - """ - if not self._isOpen: raise portNotOpenError - if enable: - termios.tcflow(self.fd, TERMIOS.TCOON) - else: - termios.tcflow(self.fd, TERMIOS.TCOOFF) - - -# assemble Serial class with the platform specifc implementation and the base -# for file-like behavior. for Python 2.6 and newer, that provide the new I/O -# library, derrive from io.RawIOBase -try: - import io -except ImportError: - # classic version with our own file-like emulation - class Serial(PosixSerial, FileLike): - pass -else: - # io library present - class Serial(PosixSerial, io.RawIOBase): - pass - -class PosixPollSerial(Serial): - """poll based read implementation. not all systems support poll properly. - however this one has better handling of errors, such as a device - disconnecting while it's in use (e.g. USB-serial unplugged)""" - - 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 self.fd is None: 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._interCharTimeout is not None and self._interCharTimeout > 0)) and not buf: - break # early abort on timeout - return bytes(read) - - -if __name__ == '__main__': - s = Serial(0, - baudrate=19200, # baud rate - bytesize=EIGHTBITS, # number of data bits - parity=PARITY_EVEN, # enable parity checking - stopbits=STOPBITS_ONE, # number of stop bits - 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') - sys.stdout.write('%r\n' % s.read(5)) - sys.stdout.write('%s\n' % s.inWaiting()) - del s - |