| #! python |
| # |
| # Python Serial Port Extension for Win32, Linux, BSD, Jython |
| # see __init__.py |
| # |
| # This module implements a simple socket based client. |
| # It does not support changing any port parameters and will silently ignore any |
| # requests to do so. |
| # |
| # The purpose of this module is that applications using pySerial can connect to |
| # TCP/IP to serial port converters that do not support RFC 2217. |
| # |
| # (C) 2001-2015 Chris Liechti <[email protected]> |
| # |
| # SPDX-License-Identifier: BSD-3-Clause |
| # |
| # URL format: socket://<host>:<port>[/option[/option...]] |
| # options: |
| # - "debug" print diagnostic messages |
| |
| import logging |
| import select |
| import socket |
| import time |
| try: |
| import urlparse |
| except ImportError: |
| import urllib.parse as urlparse |
| |
| from serial.serialutil import * |
| |
| # map log level names to constants. used in fromURL() |
| LOGGER_LEVELS = { |
| 'debug': logging.DEBUG, |
| 'info': logging.INFO, |
| 'warning': logging.WARNING, |
| 'error': logging.ERROR, |
| } |
| |
| POLL_TIMEOUT = 2 |
| |
| class Serial(SerialBase): |
| """Serial port implementation for plain sockets.""" |
| |
| BAUDRATES = (50, 75, 110, 134, 150, 200, 300, 600, 1200, 1800, 2400, 4800, |
| 9600, 19200, 38400, 57600, 115200) |
| |
| def open(self): |
| """\ |
| Open port with current settings. This may throw a SerialException |
| if the port cannot be opened. |
| """ |
| self.logger = None |
| 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.") |
| try: |
| self._socket = socket.create_connection(self.fromURL(self.portstr)) |
| except Exception as msg: |
| self._socket = None |
| raise SerialException("Could not open port %s: %s" % (self.portstr, msg)) |
| |
| self._socket.settimeout(POLL_TIMEOUT) # used for write timeout support :/ |
| |
| # not that there anything to configure... |
| self._reconfigurePort() |
| # all things set up get, now a clean start |
| self._isOpen = True |
| if not self._rtscts: |
| self.setRTS(True) |
| self.setDTR(True) |
| self.flushInput() |
| self.flushOutput() |
| |
| def _reconfigurePort(self): |
| """\ |
| Set communication parameters on opened port. For the socket:// |
| protocol all settings are ignored! |
| """ |
| if self._socket is None: |
| raise SerialException("Can only operate on open ports") |
| if self.logger: |
| self.logger.info('ignored port configuration change') |
| |
| def close(self): |
| """Close port""" |
| if self._isOpen: |
| if self._socket: |
| try: |
| self._socket.shutdown(socket.SHUT_RDWR) |
| self._socket.close() |
| except: |
| # ignore errors. |
| pass |
| self._socket = None |
| self._isOpen = False |
| # in case of quick reconnects, give the server some time |
| time.sleep(0.3) |
| |
| def makeDeviceName(self, port): |
| raise SerialException("there is no sensible way to turn numbers into URLs") |
| |
| def fromURL(self, url): |
| """extract host and port from an URL string""" |
| parts = urlparse.urlsplit(url) |
| if parts.scheme.lower() != "socket": |
| raise SerialException('expected a string in the form "socket://<host>:<port>[/option[/option...]]": not starting with socket:// (%r)' % (parts.scheme,)) |
| try: |
| # process options now, directly altering self |
| for option in parts.path.lower().split('/'): |
| if '=' in option: |
| option, value = option.split('=', 1) |
| else: |
| value = None |
| if not option: |
| pass |
| elif option == 'logging': |
| logging.basicConfig() # XXX is that good to call it here? |
| self.logger = logging.getLogger('pySerial.socket') |
| self.logger.setLevel(LOGGER_LEVELS[value]) |
| self.logger.debug('enabled logging') |
| else: |
| raise ValueError('unknown option: %r' % (option,)) |
| # get host and port |
| host, port = parts.hostname, parts.port |
| if not 0 <= port < 65536: raise ValueError("port not in range 0...65535") |
| except ValueError as e: |
| raise SerialException('expected a string in the form "socket://<host>:<port>[/option[/option...]]": %s' % e) |
| return (host, port) |
| |
| # - - - - - - - - - - - - - - - - - - - - - - - - |
| |
| def inWaiting(self): |
| """Return the number of characters currently in the input buffer.""" |
| if not self._isOpen: raise portNotOpenError |
| # Poll the socket to see if it is ready for reading. |
| # If ready, at least one byte will be to read. |
| lr, lw, lx = select.select([self._socket], [], [], 0) |
| return len(lr) |
| |
| 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 |
| data = bytearray() |
| if self._timeout is not None: |
| timeout = time.time() + self._timeout |
| else: |
| timeout = None |
| while len(data) < size: |
| try: |
| # an implementation with internal buffer would be better |
| # performing... |
| block = self._socket.recv(size - len(data)) |
| if block: |
| data.extend(block) |
| else: |
| # no data -> EOF (connection probably closed) |
| break |
| except socket.timeout: |
| # just need to get out of recv from time to time to check if |
| # still alive |
| continue |
| except socket.error as e: |
| # connection fails -> terminate loop |
| raise SerialException('connection failed (%s)' % e) |
| if timeout is not None and time.time() > timeout: |
| break |
| return bytes(data) |
| |
| def write(self, data): |
| """\ |
| Output the given string over the serial port. Can block if the |
| connection is blocked. May raise SerialException if the connection is |
| closed. |
| """ |
| if not self._isOpen: raise portNotOpenError |
| try: |
| self._socket.sendall(to_bytes(data)) |
| except socket.error as e: |
| # XXX what exception if socket connection fails |
| raise SerialException("socket connection failed: %s" % e) |
| return len(data) |
| |
| def flushInput(self): |
| """Clear input buffer, discarding all that is in the buffer.""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('ignored flushInput') |
| |
| def flushOutput(self): |
| """\ |
| Clear output buffer, aborting the current output and |
| discarding all that is in the buffer. |
| """ |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('ignored flushOutput') |
| |
| def sendBreak(self, duration=0.25): |
| """\ |
| Send break condition. Timed, returns to idle state after given |
| duration. |
| """ |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('ignored sendBreak(%r)' % (duration,)) |
| |
| def setBreak(self, level=True): |
| """Set break: Controls TXD. When active, to transmitting is |
| possible.""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('ignored setBreak(%r)' % (level,)) |
| |
| def setRTS(self, level=True): |
| """Set terminal status line: Request To Send""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('ignored setRTS(%r)' % (level,)) |
| |
| def setDTR(self, level=True): |
| """Set terminal status line: Data Terminal Ready""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('ignored setDTR(%r)' % (level,)) |
| |
| def getCTS(self): |
| """Read terminal status line: Clear To Send""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('returning dummy for getCTS()') |
| return True |
| |
| def getDSR(self): |
| """Read terminal status line: Data Set Ready""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('returning dummy for getDSR()') |
| return True |
| |
| def getRI(self): |
| """Read terminal status line: Ring Indicator""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('returning dummy for getRI()') |
| return False |
| |
| def getCD(self): |
| """Read terminal status line: Carrier Detect""" |
| if not self._isOpen: raise portNotOpenError |
| if self.logger: |
| self.logger.info('returning dummy for getCD()') |
| return True |
| |
| # - - - platform specific - - - |
| |
| # works on Linux and probably all the other POSIX systems |
| def fileno(self): |
| """Get the file handle of the underlying socket for use with select""" |
| return self._socket.fileno() |
| |
| |
| # |
| # simple client test |
| if __name__ == '__main__': |
| import sys |
| s = Serial('socket://localhost:7000') |
| sys.stdout.write('%s\n' % s) |
| |
| sys.stdout.write("write...\n") |
| s.write(b"hello\n") |
| s.flush() |
| sys.stdout.write("read: %s\n" % s.read(5)) |
| |
| s.close() |
