diff options
Diffstat (limited to 'glucometerutils/support/lifescan_binary_protocol.py')
| -rw-r--r-- | glucometerutils/support/lifescan_binary_protocol.py | 57 |
1 files changed, 31 insertions, 26 deletions
diff --git a/glucometerutils/support/lifescan_binary_protocol.py b/glucometerutils/support/lifescan_binary_protocol.py index 0143cd4..92a0002 100644 --- a/glucometerutils/support/lifescan_binary_protocol.py +++ b/glucometerutils/support/lifescan_binary_protocol.py @@ -18,36 +18,41 @@ from glucometerutils import common from glucometerutils.support import construct_extras from glucometerutils.support import lifescan +_LINK_CONTROL = construct.BitStruct( + construct.Padding(3), + 'more' / construct.Default(construct.Flag, False), + 'disconnect' / construct.Default(construct.Flag, False), + 'acknowledge' / construct.Default(construct.Flag, False), + 'expect_receive' / construct.Default(construct.Flag, False), + 'sequence_number' / construct.Default(construct.Flag, False), +) + +def LifeScanPacket(command_prefix, include_link_control): + if include_link_control: + link_control_construct = _LINK_CONTROL + else: + link_control_construct = construct.Const(b'\x00') -PACKET = construct.Struct( - construct.RawCopy( - construct.Embedded( - construct.Struct( - construct.Const(b'\x02'), # stx - 'length' / construct.Rebuild( - construct.Byte, lambda ctx: len(ctx.message) + 6), - # The following structure is only used by some of the devices. - 'link_control' / construct.BitStruct( - construct.Padding(3), - 'more' / construct.Default( - construct.Flag, False), - 'disconnect' / construct.Default( - construct.Flag, False), - 'acknowledge' / construct.Default( - construct.Flag, False), - 'expect_receive' / construct.Default( - construct.Flag, False), - 'sequence_number' / construct.Default( - construct.Flag, False), + command_prefix_construct = construct.Const(construct.Byte, command_prefix) + + return construct.Struct( + construct.RawCopy( + construct.Embedded( + construct.Struct( + construct.Const(b'\x02'), # stx + 'length' / construct.Rebuild( + construct.Byte, lambda ctx: len(ctx.message) + 7), + 'link_control' / link_control_construct, + 'command_prefix' / command_prefix_construct, + 'message' / construct.Bytes( + length=lambda ctx: ctx.length - 7), + construct.Const(b'\x03'), # etx ), - 'message' / construct.Bytes(length=lambda ctx: ctx.length - 6), - construct.Const(b'\x03'), # etx ), ), - ), - 'checksum' / construct.Checksum( - construct.Int16ul, lifescan.crc_ccitt, construct.this.data), -) + 'checksum' / construct.Checksum( + construct.Int16ul, lifescan.crc_ccitt, construct.this.data), + ) VERIO_TIMESTAMP = construct_extras.Timestamp( construct.Int32ul, epoch=946684800) # 2010-01-01 00:00 |