1 files changed, 66 insertions, 0 deletions

diff --git a/glucometerutils/support/serial.py b/glucometerutils/support/serial.py
new file mode 100644
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+++ b/glucometerutils/support/serial.py
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+"""Common routines and base driver class for serial-based meters.
+"""
+
+__author__ = 'Diego Elio Pettenò'
+__email__ = 'flameeyes@flameeyes.eu'
+__copyright__ = 'Copyright © 2017, Diego Elio Pettenò'
+__license__ = 'MIT'
+
+import logging
+
+import serial
+
+from glucometerutils import exceptions
+
+
+class SerialDevice(object):
+    """A Serial-connected glucometer driver base.
+
+    This class does not implement an actual driver by itself, but provides an
+    easier access to the boilerplate code required for pyserial.
+
+    This helper assumes that communication happens on a standard 8n1
+    configuration, with variable baudrate and no hardware flow control.
+
+    The actual drivers should set the following parameters:
+
+      BAUDRATE: (int) the speed the serial port should be opened at.
+      DEFAULT_CABLE_ID: (string) USB Vendor/Product ID pair, in format
+        abcd:abcd, of the default cable for the meter, in case the user
+        didn't pass an explicit device driver.
+
+    Optional parameters available:
+
+      TIMEOUT: (float, default: 1) the read timeout in seconds as defined by
+        pyserial.
+
+    After initialization, the following attributes can be used by the driver:
+      serial_: (serial.Serial) the open Serial object.
+
+    """
+
+    BAUDRATE = None
+    DEFAULT_CABLE_ID = None
+
+    TIMEOUT = 1
+
+    def __init__(self, device):
+        assert self.BAUDRATE is not None
+
+        if not device and self.DEFAULT_CABLE_ID:
+            logging.info(
+                'No --device parameter provided, looking for default cable.')
+            device = 'hwgrep://' + self.DEFAULT_CABLE_ID
+
+        if not device:
+            raise exceptions.CommandLineError(
+                'No --device parameter provided, and no default cable known.')
+
+        self.serial_ = serial.serial_for_url(
+            device,
+            baudrate=self.BAUDRATE,
+            timeout=self.TIMEOUT,
+            writeTimeout=None,
+            bytesize=serial.EIGHTBITS, parity=serial.PARITY_NONE,
+            stopbits=serial.STOPBITS_ONE,
+            xonxoff=True, rtscts=False, dsrdtr=False)