Adafruit_CircuitPython_Blue.../adafruit_bluefruit_connect/location_packet.py
2020-03-16 14:56:41 -04:00

81 lines
2.6 KiB
Python

# The MIT License (MIT)
#
# Copyright (c) 2019 Dan Halbert for Adafruit Industries
#
# Permission is hereby granted, free of charge, to any person obtaining a copy
# of this software and associated documentation files (the "Software"), to deal
# in the Software without restriction, including without limitation the rights
# to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
# copies of the Software, and to permit persons to whom the Software is
# furnished to do so, subject to the following conditions:
#
# The above copyright notice and this permission notice shall be included in
# all copies or substantial portions of the Software.
#
# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
# IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
# FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
# AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
# LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
# OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
# THE SOFTWARE.
"""
`adafruit_bluefruit_connect.location_packet`
====================================================
Bluefruit Connect App geographical location packet.
* Author(s): Dan Halbert for Adafruit Industries
"""
import struct
from .packet import Packet
class LocationPacket(Packet):
"""A packet of latitude, longitude, and altitude values."""
_FMT_PARSE = "<xxfffx"
PACKET_LENGTH = struct.calcsize(_FMT_PARSE)
# _FMT_CONSTRUCT doesn't include the trailing checksum byte.
_FMT_CONSTRUCT = "<2sfff"
_TYPE_HEADER = b"!L"
def __init__(self, latitude, longitude, altitude):
"""Construct a LocationPacket from the given values."""
self._latitude = latitude
self._longitude = longitude
self._altitude = altitude
def to_bytes(self):
"""Return the bytes needed to send this packet.
"""
partial_packet = struct.pack(
self._FMT_CONSTRUCT,
self._TYPE_HEADER,
self._latitude,
self._longitude,
self._altitude,
)
return self.add_checksum(partial_packet)
@property
def latitude(self):
"""The latitude value."""
return self._latitude
@property
def longitude(self):
"""The longitude value."""
return self._longitude
@property
def altitude(self):
"""The altitude value."""
return self._altitude
# Register this class with the superclass. This allows the user to import only what is needed.
LocationPacket.register_packet_type()