From fc60f8b714dfde13c61caf1c3792073516d9c556 Mon Sep 17 00:00:00 2001
From: Stefanie Tellex <stefie10@alum.mit.edu>
Date: Fri, 29 Oct 2021 21:21:22 -0400
Subject: freedomlite initial commit

---
 glucometerutils/drivers/fsfreedomlite.py | 266 +++++++++++++++++++++++++++++++
 1 file changed, 266 insertions(+)
 create mode 100644 glucometerutils/drivers/fsfreedomlite.py

diff --git a/glucometerutils/drivers/fsfreedomlite.py b/glucometerutils/drivers/fsfreedomlite.py
new file mode 100644
index 0000000..f2a9db8
--- /dev/null
+++ b/glucometerutils/drivers/fsfreedomlite.py
@@ -0,0 +1,266 @@
+# -*- coding: utf-8 -*-
+#
+# SPDX-FileCopyrightText: © 2021 Stefanie Tellex
+# SPDX-License-Identifier: MIT
+"""Driver for FreeStyle Freedom Lite devices.
+
+Supported features:
+    - get readings (ignores ketone results);
+    - use the glucose unit preset on the device by default;
+    - get and set date and time;
+    - get serial number and software version.
+
+Expected device path: /dev/ttyUSB0 or similar serial port device.
+
+Further information on the device protocol can be found at
+
+https://protocols.glucometers.tech/abbott/freestyle-optium
+"""
+
+import datetime
+import logging
+import re
+from typing import Generator, NoReturn, Sequence
+
+from glucometerutils import common, driver, exceptions
+from glucometerutils.support import serial
+
+_CLOCK_RE = re.compile(
+    r"^Clock:\t(?P<month>[A-Z][a-z]{2})  (?P<day>[0-9]{2}) (?P<year>[0-9]{4})\t"
+    r"(?P<time>[0-9]{2}:[0-9]{2}:[0-9]{2})$"
+)
+
+# The reading can be HI (padded to three-characters by a space) if the value was
+# over what the meter was supposed to read. Unlike the "Clock:" line, the months
+# of June and July are written in full, everything else is truncated to three
+# characters, so accept a space or 'e'/'y' at the end of the month name. Also,
+# the time does *not* include seconds.
+_READING_RE = re.compile(
+    r"^(?P<reading>HI |[0-9]{3})  "
+    r"(?P<month>[A-Z][a-z]{2})[ ey] "
+    r"(?P<day>[0-9]{2}) "
+    r"(?P<year>[0-9]{4}) "
+    r"(?P<time>[0-9]{2}:[0-9]{2}) "
+    r"(?P<type>[GK]) 0x00$"
+)
+
+_CHECKSUM_RE = re.compile(r"^(?P<checksum>0x[0-9A-F]{4})  END$")
+
+# There are two date format used by the device. One uses three-letters month
+# names, and that's easy enough. The other uses three-letters month names,
+# except for (at least) July. So ignore the fourth character.
+# explicit mapping. Note that the mapping *requires* a trailing whitespace.
+_MONTH_MATCHES = {
+    "Jan": 1,
+    "Feb": 2,
+    "Mar": 3,
+    "Apr": 4,
+    "May": 5,
+    "Jun": 6,
+    "Jul": 7,
+    "Aug": 8,
+    "Sep": 9,
+    "Oct": 10,
+    "Nov": 11,
+    "Dec": 12,
+}
+
+
+def _parse_clock(datestr: str) -> datetime.datetime:
+    """Convert the date/time string used by the device into a datetime.
+
+    Args:
+      datestr: a string as returned by the device during information handling.
+    """
+    match = _CLOCK_RE.match(datestr)
+    if not match:
+        raise exceptions.InvalidResponse(datestr)
+
+    # int() parses numbers in decimal, so we don't have to worry about '08'
+    day = int(match.group("day"))
+    month = _MONTH_MATCHES[match.group("month")]
+    year = int(match.group("year"))
+
+    hour, minute, second = (int(x) for x in match.group("time").split(":"))
+
+    return datetime.datetime(year, month, day, hour, minute, second)
+
+
+class Device(serial.SerialDevice, driver.GlucometerDevice):
+    BAUDRATE = 19200
+    DEFAULT_CABLE_ID = "1a61:3420"
+
+    def _send_command(self, command: str) -> Sequence[str]:
+        cmd_bytes = bytes("$%s\r\n" % command, "ascii")
+        logging.debug("Sending command: %r", cmd_bytes)
+
+        self.serial_.write(cmd_bytes)
+        self.serial_.flush()
+
+        response = self.serial_.readlines()
+
+        logging.debug("Received response: %r", response)
+
+        # We always want to decode the output, and remove stray \r\n. Any
+        # failure in decoding means the output is invalid anyway.
+        decoded_response = [line.decode("ascii").rstrip("\r\n") for line in response]
+        return decoded_response
+
+    def connect(self) -> None:
+        self._send_command("xmem")  # ignore output this time
+        self._fetch_device_information()
+
+    def disconnect(self) -> None:  # pylint: disable=no-self-use
+        return
+
+    def _fetch_device_information(self) -> None:
+        data = self._send_command("colq")
+
+        for line in data:
+            parsed_line = line.split("\t")
+
+            if parsed_line[0] == "S/N:":
+                self.device_serialno_ = parsed_line[1]
+            elif parsed_line[0] == "Ver:":
+                self.device_version_ = parsed_line[1]
+                if parsed_line[2] == "MMOL":
+                    self.device_glucose_unit_ = common.Unit.MMOL_L
+                else:  # I only have a mmol/l device, so I can't be sure.
+                    self.device_glucose_unit_ = common.Unit.MG_DL
+            # There are more entries: Clock, Market, ROM and Usage, but we don't
+            # care for those here.
+            elif parsed_line[0] == "CMD OK":
+                return
+
+        # I have not figured out why this happens, but sometimes it's echoing
+        # back the commands and not replying to them.
+        raise exceptions.ConnectionFailed()
+
+    def get_meter_info(self) -> common.MeterInfo:
+        """Fetch and parses the device information.
+
+        Returns:
+          A common.MeterInfo object.
+        """
+        return common.MeterInfo(
+            "Freestyle Optium glucometer",
+            serial_number=self.get_serial_number(),
+            version_info=("Software version: " + self.get_version(),),
+            native_unit=self.get_glucose_unit(),
+        )
+
+    def get_version(self) -> str:
+        """Returns an identifier of the firmware version of the glucometer.
+
+        Returns:
+          The software version returned by the glucometer, such as "0.22"
+        """
+        return self.device_version_
+
+    def get_serial_number(self) -> str:
+        """Retrieve the serial number of the device.
+
+        Returns:
+          A string representing the serial number of the device.
+        """
+        return self.device_serialno_
+
+    def get_glucose_unit(self) -> common.Unit:
+        """Returns a constant representing the unit displayed by the meter.
+
+        Returns:
+          common.Unit.MG_DL: if the glucometer displays in mg/dL
+          common.Unit.MMOL_L: if the glucometer displays in mmol/L
+        """
+        return self.device_glucose_unit_
+
+    def get_datetime(self) -> datetime.datetime:
+        """Returns the current date and time for the glucometer.
+
+        Returns:
+          A datetime object built according to the returned response.
+        """
+        data = self._send_command("colq")
+
+        for line in data:
+            if not line.startswith("Clock:"):
+                continue
+
+            return _parse_clock(line)
+
+        raise exceptions.InvalidResponse("\n".join(data))
+
+    def _set_device_datetime(self, date: datetime.datetime) -> datetime.datetime:
+        data = self._send_command(date.strftime("tim,%m,%d,%y,%H,%M"))
+
+        parsed_data = "".join(data)
+        if parsed_data != "CMD OK":
+            raise exceptions.InvalidResponse(parsed_data)
+
+        return self.get_datetime()
+
+    def zero_log(self) -> NoReturn:
+        raise NotImplementedError
+
+    def get_readings(self) -> Generator[common.AnyReading, None, 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.
+
+        """
+        data = self._send_command("xmem")
+
+        # The first line is empty, the second is the serial number, the third
+        # the version, the fourth the current time, and the fifth the record
+        # count.. The last line has a checksum and the end.
+        count = int(data[4])
+        if count != (len(data) - 6):
+            raise exceptions.InvalidResponse("\n".join(data))
+
+        # Extract the checksum from the last line.
+        checksum_match = _CHECKSUM_RE.match(data[-1])
+        if not checksum_match:
+            raise exceptions.InvalidResponse("\n".join(data))
+
+        expected_checksum = int(checksum_match.group("checksum"), 16)
+        # exclude the last line in the checksum calculation, as that's the
+        # checksum itself. The final \r\n is added separately.
+        calculated_checksum = sum(ord(c) for c in "\r\n".join(data[:-1])) + 0xD + 0xA
+
+        if expected_checksum != calculated_checksum:
+            raise exceptions.InvalidChecksum(expected_checksum, calculated_checksum)
+
+        for line in data[5:-1]:
+            match = _READING_RE.match(line)
+            if not match:
+                raise exceptions.InvalidResponse(line)
+
+            if match.group("type") != "G":
+                logging.warning("Non-glucose readings are not supported, ignoring.")
+                continue
+
+            if match.group("reading") == "HI ":
+                value = float("inf")
+            else:
+                value = float(match.group("reading"))
+
+            day = int(match.group("day"))
+            month = _MONTH_MATCHES[match.group("month")]
+            year = int(match.group("year"))
+
+            hour, minute = map(int, match.group("time").split(":"))
+
+            timestamp = datetime.datetime(year, month, day, hour, minute)
+
+            # The reading, if present, is always in mg/dL even if the glucometer
+            # is set to mmol/L.
+            yield common.GlucoseReading(timestamp, value)
-- 
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