src.bluetooth_sig.gatt.characteristics.cgm_session_start_time

CGM Session Start Time characteristic implementation.

Implements the CGM Session Start Time characteristic (0x2AAA).

Structure (from GSS YAML):

Session Start Time (7 bytes) – DateTime struct (year+month+day+h+m+s) Time Zone (1 byte, uint8) – offset from UTC in 15-minute increments DST Offset (1 byte, uint8) – DST adjustment code E2E-CRC (2 bytes, uint16, optional)

References

Bluetooth SIG Continuous Glucose Monitoring Service org.bluetooth.characteristic.cgm_session_start_time (GSS YAML)

Classes

Name	Description
CGMSessionStartTimeCharacteristic	CGM Session Start Time characteristic (0x2AAA).
CGMSessionStartTimeData	Parsed data from CGM Session Start Time characteristic.

Module Contents

class src.bluetooth_sig.gatt.characteristics.cgm_session_start_time.CGMSessionStartTimeCharacteristic(info: src.bluetooth_sig.types.CharacteristicInfo | None = None, validation: src.bluetooth_sig.gatt.characteristics.characteristic_meta.ValidationConfig | None = None)

Bases: src.bluetooth_sig.gatt.characteristics.base.BaseCharacteristic[CGMSessionStartTimeData]

CGM Session Start Time characteristic (0x2AAA).

Reports the session start time, time zone, and DST offset for a CGM session.

allow_variable_length: bool = True

expected_type

min_length: int = 9

class src.bluetooth_sig.gatt.characteristics.cgm_session_start_time.CGMSessionStartTimeData

Bases: msgspec.Struct

Parsed data from CGM Session Start Time characteristic.

start_time

Session start date and time.

time_zone

Time zone offset from UTC in 15-minute increments.

dst_offset

DST adjustment code.

e2e_crc

E2E-CRC value. None if absent.

dst_offset: src.bluetooth_sig.gatt.characteristics.dst_offset.DSTOffset

e2e_crc: int | None = None

start_time: datetime.datetime

time_zone: int