1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
|
# -*- coding: utf-8 -*-
#
# SPDX-License-Identifier: MIT
"""Driver for SD CodeFree devices by SD Biosensor.
For SD Biosensor glucometers using the serial interface.
Supported features:
- get readings, including pre-/post-meal notes;
- set date and time.
Expected device path: /dev/ttyUSB0 or similar serial port device.
IMPORTANT NOTE: the glucometer can be connected before starting the program, but
it has to be turned on when the program asks you to.
"""
import binascii
import datetime
import enum
import functools
import logging
import operator
import construct
from glucometerutils import common
from glucometerutils import exceptions
from glucometerutils.support import serial
def xor_checksum(msg):
return functools.reduce(operator.xor, msg)
class Direction(enum.Enum):
In = 0x20
Out = 0x10
_PACKET = construct.Struct(
'stx' / construct.Const(0x53, construct.Byte),
'direction' / construct.Mapping(
construct.Byte,
{e: e.value for e in Direction}),
'length' / construct.Rebuild(
construct.Byte, lambda this: len(this.message) + 2),
'message' / construct.Bytes(lambda this: this.length - 2),
'checksum' / construct.Checksum(
construct.Byte, xor_checksum, construct.this.message),
'etx' / construct.Const(0xAA, construct.Byte)
)
_FIRST_MESSAGE = construct.Struct(
construct.Const(0x30, construct.Byte),
'count' / construct.Int16ub,
construct.Const(0xAA, construct.Byte)[19],
)
_CHALLENGE_PACKET_FULL = b'\x53\x20\x04\x10\x30\x20\xAA'
_RESPONSE_MESSAGE = b'\x10\x40'
_DATE_SET_MESSAGE = b'\x10\x10'
_DISCONNECT_MESSAGE = b'\x10\x60'
_DISCONNECTED_MESSAGE = b'\x10\x70'
_FETCH_MESSAGE = b'\x10\x60'
_MEAL_FLAG = {
common.Meal.NONE: 0x00,
common.Meal.BEFORE: 0x10,
common.Meal.AFTER: 0x20,
}
_READING = construct.Struct(
construct.Byte[2],
'year' / construct.Byte,
'month' / construct.Byte,
'day' / construct.Byte,
'hour' / construct.Byte,
'minute' / construct.Byte,
'value' / construct.Int16ub,
'meal' / construct.Mapping(
construct.Byte, _MEAL_FLAG),
construct.Byte[7],
)
class Device(serial.SerialDevice):
BAUDRATE = 38400
DEFAULT_CABLE_ID = '10c4:ea60' # Generic cable.
TIMEOUT = 300 # We need to wait for data from the device.
def read_message(self):
pkt = _PACKET.parse_stream(self.serial_)
logging.debug('received packet: %r', pkt)
return pkt.message
def wait_and_ready(self):
challenge = b'\0'
while challenge == b'\0':
challenge = self.serial_.read(1)
# The first packet read may have a prefixed zero, it might be a bug
# in the cp210x driver or device, but discard it if found.
if challenge == b'\0':
logging.debug('spurious null byte received')
continue
if challenge != b'\x53':
raise exceptions.ConnectionFailed(
message='Unexpected starting bytes %r' % challenge)
challenge += self.serial_.read(6)
if challenge != _CHALLENGE_PACKET_FULL:
raise exceptions.ConnectionFailed(
message='Unexpected challenge %r' % challenge)
logging.debug(
'challenge packet received: %s', binascii.hexlify(challenge))
self.send_message(_RESPONSE_MESSAGE)
# The first packet only contains the counter of how many readings are
# available.
first_message = _FIRST_MESSAGE.parse(self.read_message())
logging.debug('received first message: %r', first_message)
return first_message.count
def send_message(self, message):
pkt = _PACKET.build({
'message': message,
'direction': Direction.Out
})
logging.debug('sending packet: %s', binascii.hexlify(pkt))
self.serial_.write(pkt)
def connect(self): # pylint: disable=no-self-use
print("Please connect and turn on the device.")
def disconnect(self):
self.send_message(_DISCONNECT_MESSAGE)
response = self.read_message()
if response != _DISCONNECTED_MESSAGE:
raise exceptions.InvalidResponse(response=response)
def get_meter_info(self): # pylint: disable=no-self-use
return common.MeterInfo('SD CodeFree glucometer')
def get_version(self): # pylint: disable=no-self-use
raise NotImplementedError
def get_serial_number(self): # pylint: disable=no-self-use
raise NotImplementedError
def get_glucose_unit(self): # pylint: disable=no-self-use
# Device does not provide information on glucose unit.
return common.Unit.MG_DL
def get_datetime(self): # pylint: disable=no-self-use
raise NotImplementedError
def set_datetime(self, date=datetime.datetime.now()):
setdatecmd = date.strftime('ADATE%Y%m%d%H%M').encode('ascii')
# Ignore the readings count.
self.wait_and_ready()
self.send_message(setdatecmd)
response = self.read_message()
if response != _DATE_SET_MESSAGE:
raise exceptions.InvalidResponse(response=response)
# The date we return should only include up to minute, unfortunately.
return datetime.datetime(date.year, date.month, date.day,
date.hour, date.minute)
def zero_log(self):
raise NotImplementedError
def get_readings(self):
count = self.wait_and_ready()
for _ in range(count):
self.send_message(_FETCH_MESSAGE)
message = self.read_message()
reading = _READING.parse(message)
logging.debug('received reading: %r', reading)
yield common.GlucoseReading(
datetime.datetime(
2000 + reading.year, reading.month,
reading.day, reading.hour, reading.minute),
reading.value, meal=reading.meal)
|
