Initial serial_interface implementation

__init__.py

@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+# -*- coding: utf-8 -*-
+#
+"""
+serial_interface (Serial Interface Module)
+==========================================
+
+**Author:**
+
+* Dirk Alders <sudo-dirk@mount-mockery.de>
+
+**Description:**
+
+    This Module supports a common interface for a serial port
+
+**Submodules:**
+
+* :mod:`mmod.module.sub1`
+* :class:`mmod.module.sub2`
+* :func:`mmod.module.sub2`
+
+**Unittest:**
+
+        See also the :download:`unittest <../../serial_interface/_testresults_/unittest.pdf>` documentation.
+"""
+__DEPENDENCIES__ = ['stringtools']
+
+import stringtools
+
+import logging
+import serial
+import time
+
+logger_name = 'SERIAL_INTERFACE'
+logger = logging.getLogger(logger_name)
+
+
+class serial_interface(object):
+    """
+    Class to send and receive data via a serial port.
+
+    .. note:: All parameters are given to the standard :py:class:`serial.Serial` library
+    """
+    LOG_PREFIX = 'SER:'
+
+    def __init__(self, *args, **kwargs):
+        self._args = args
+        self._kwargs = kwargs
+        self.com = None
+        self.open()
+
+    def open(self):
+        """
+        This opens the serial port.
+
+        :returns: True if the port has been successfully opened
+        :rtype: bool
+        """
+        if self.com is not None:
+            self.close()
+        try:
+            self.com = serial.Serial(*self._args, **self._kwargs)
+        except:
+            self.com = None
+            logger.warning('%s Unable to open comport (%s)', self.LOG_PREFIX, self._args[0])
+            return False
+        else:
+            logger.debug('%s Opening comport (%s)', self.LOG_PREFIX, self._args[0])
+        return True
+
+    def close(self):
+        """
+        This closes the serial port.
+        """
+        if self.com is not None:
+            logger.debug('%s Closing comport (%s)', self.LOG_PREFIX, self._args[0])
+            self.com.close()
+            self.com = None
+
+    def bytes_in_queue(self):
+        """
+        This returns the number of available bytes for receiption.
+
+        :returns: Number of bytes in queue
+        :rtype: int
+        """
+        if self.com is not None:
+            return self.com.inWaiting()
+        else:
+            return 0
+
+    def receive(self, max_length=None):
+        """
+        This receives data from the serial interface.
+
+        :param int length: An optinal number of bytes to be received. None will return all available bytes.
+        :returns: The received data
+        :rtype: str
+        """
+        length = self.bytes_in_queue()
+        if max_length is not None:
+            length = min(length, max_length)
+        if self.com is not None and length > 0:
+            data = self.com.read(length)
+            self._handle_debug('RX <- ', data)
+            return data
+
+    def send(self, data):
+        """
+        This sends data via the serial interface.
+
+        :param str data: The data to be send
+        """
+        if self.com is not None:
+            self._handle_debug('TX -> ', data)
+            self.com.write(data)
+
+    def _handle_debug(self, msg, data):
+        logger.debug('%s ' + msg + stringtools.hexlify(data), self.LOG_PREFIX)
+
+    def __del__(self):
+        self.close()