"""Driver for LifeScan OneTouch Ultra 2 devices"""
__author__ = 'Diego Elio Pettenò'
__email__ = 'flameeyes@flameeyes.eu'
__copyright__ = 'Copyright © 2013, Diego Elio Pettenò'
__license__ = 'GPL v3 or later'
import datetime
import re
import serial
from glucometerutils import common
from glucometerutils import exceptions
class MissingChecksum(exceptions.InvalidResponse):
"""The response misses the expected 4-digits checksum."""
def __init__(self, response):
self.response = response
def __str__(self):
return 'Response is missing the OT2 checksum: %s' % self.response
class InvalidSerialNumber(exceptions.Error):
"""The serial number is not ending with Y as expected."""
class Device(object):
def __init__(self, device):
self.serial_ = serial.Serial(
port=device, baudrate=9600, bytesize=serial.EIGHTBITS,
parity=serial.PARITY_NONE, stopbits=serial.STOPBITS_ONE,
timeout=1, xonxoff=False, rtscts=False, dsrdtr=False, writeTimeout=None)
def _SendCommand(self, cmd):
"""Send command interface.
Args:
cmd: command and parameters to send (without newline)
This function exists to wrap the need to send the 0x11 0x0d prefix with
each command that wakes this model up.
"""
cmdstring = bytes('\x11\r' + cmd + '\r', 'ascii')
self.serial_.write(cmdstring);
self.serial_.flush()
_RESPONSE_MATCH = re.compile(r'^(.+) ([0-9A-F]{4})\r$')
def _ValidateAndStripChecksum(self, line):
"""Verify the CRC16 checksum and remove it from the line.
Args:
line: the line to check the CRC16 of.
Returns:
A copy of the line with the CRC16 stripped out.
"""
match = self._RESPONSE_MATCH.match(line)
if not match:
raise MissingChecksum(line)
response, checksum = match.groups()
# TODO(flameeyes) check that the checksum is actually valid
return response
def _SendOnelinerCommand(self, cmd):
"""Send command and read a one-line response.
Args:
cmd: command and parameters to send (without newline)
Returns:
A single line of text that the glucometer responds, without the checksum.
"""
self._SendCommand(cmd)
line = self.serial_.readline().decode('ascii')
return self._ValidateAndStripChecksum(line)
def GetVersion(self):
"""Returns an identifier of the firmware version of the glucometer.
Returns:
The software version returned by the glucometer, such as
"P02.00.00 30/08/06".
"""
response = self._SendOnelinerCommand('DM?')
if response[0] != '?':
raise InvalidResponse(response)
return response[1:]
_SERIAL_NUMBER_RE = re.compile('^@ "([A-Z0-9]{9})"$')
def GetSerialNumber(self):
"""Retrieve the serial number of the device.
Returns:
A string representing the serial number of the device.
Raises:
exceptions.InvalidResponse: if the DM@ command returns a string not
matching _SERIAL_NUMBER_RE.
InvalidSerialNumber: if the returned serial number does not match
the OneTouch2 device as per specs.
"""
response = self._SendOnelinerCommand('DM@')
match = self._SERIAL_NUMBER_RE.match(response)
if not match:
raise exceptions.InvalidResponse(response)
serial_number = match.group(1)
# 'Y' at the far right of the serial number is the indication of a OneTouch
# Ultra2 device, as per specs.
if serial_number[-1] != 'Y':
raise InvalidSerialNumber('Serial number %s is invalid.' % serial_number)
return serial_number
# The [TF] at the start is to accept both Get (F) and Set (T) commands.
_DATETIME_RE = re.compile(
r'^"[A-Z]{3}","([0-9]{2}/[0-9]{2}/[0-9]{2})","([0-9]{2}:[0-9]{2}:[0-9]{2}) "$')
def _ParseDateTime(self, response):
"""Convert a response with date and time from the meter into a datetime.
Args:
response: the response coming from a DMF or DMT command
Returns:
A datetime object built according to the returned response.
Raises:
InvalidResponse if the string cannot be matched by _DATETIME_RE.
"""
match = self._DATETIME_RE.match(response)
if not match:
raise exceptions.InvalidResponse(response)
date, time = match.groups()
month, day, year = [int(part) for part in date.split('/')]
hour, minute, second = [int(part) for part in time.split(':')]
# Yes, OneTouch2's firmware is not Y2K safe.
return datetime.datetime(2000 + year, month, day, hour, minute, second)
def GetDateTime(self):
"""Returns the current date and time for the glucometer.
Returns:
A datetime object built according to the returned response.
"""
response = self._SendOnelinerCommand('DMF')
return self._ParseDateTime(response[2:])
def SetDateTime(self, date=datetime.datetime.now()):
"""Sets the date and time of the glucometer.
Args:
date: The value to set the date/time of the glucometer to. If none is
given, the current date and time of the computer is used.
Returns:
A datetime object built according to the returned response.
"""
response = self._SendOnelinerCommand(
'DMT' + date.strftime('%m/%d/%y %H:%M:%S'))
return self._ParseDateTime(response[2:])
def _ParseGlucoseUnit(self, unit):
"""Parses the value of a OneTouch Ultra Glucose unit definition.
Args:
unit: the string reported by the glucometer as glucose unit.
Return:
common.UNIT_MGDL: if the glucometer reads in mg/dL
common.UNIT_MMOLL: if the glucometer reads in mmol/L
Raises:
exceptions.InvalidGlucoseUnit: if the unit is not recognized
"""
if unit == 'MG/DL ':
return common.UNIT_MGDL
elif unit == 'MMOL/L':
return common.UNIT_MMOLL
else:
raise exceptions.InvalidGlucoseUnit(string)
_GLUCOSE_UNIT_RE = re.compile(r'^SU\?,"(MG/DL |MMOL/L)"')
def GetGlucoseUnit(self):
"""Returns a constant representing the unit for the dumped readings.
Returns:
common.UNIT_MGDL: if the glucometer reads in mg/dL
common.UNIT_MMOLL: if the glucometer reads in mmol/L
"""
response = self._SendOnelinerCommand('DMSU?')
match = self._GLUCOSE_UNIT_RE.match(response)
return self._ParseGlucoseUnit(match.group(1))
_DUMP_HEADER_RE = re.compile(r'P ([0-9]{3}),"[0-9A-Z]{9}","(MG/DL |MMOL/L)"')
_DUMP_LINE_RE = re.compile(r'P ("[A-Z]{3}","[0-9/]{8}","[0-9:]{8} "),"([ 0-9.]{6})",')
def GetReadings(self, unit=None):
"""Iterates over the reading values stored in the glucometer.
Args:
unit: The glucose unit to use for the output.
Yields:
A tuple (date, value) of the readings in the glucometer. The value is a
floating point in the unit specified; if no unit is specified, the default
unit in the glucometer will be used.
Raises:
exceptions.InvalidResponse: if the response does not match what expected.
"""
self._SendCommand('DMP')
data = self.serial_.readlines()
header = data.pop(0).decode('ascii')
match = self._DUMP_HEADER_RE.match(header)
if not match:
raise exceptions.InvalidResponse(header)
final_unit = unit or self._ParseGlucoseUnit(match.group(2))
count = int(match.group(1))
assert count == len(data)
for line in data:
line = self._ValidateAndStripChecksum(line.decode('ascii'))
match = self._DUMP_LINE_RE.match(line)
if not match:
raise exceptions.InvalidResponse(line)
date = self._ParseDateTime(match.group(1))
# OneTouch2 always returns the data in mg/dL even if the
# glucometer is set to mmol/L. We need to convert it to the
# requested unit here.
value = common.ConvertGlucoseUnit(int(match.group(2)),
common.UNIT_MGDL, unit)
yield (date, value)
