examples/run_channel_sounding.py

# Copyright 2024 Google LLC
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#      https://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

# -----------------------------------------------------------------------------
# Imports
# -----------------------------------------------------------------------------
from __future__ import annotations

import asyncio
import sys
import functools

from bumble import core
from bumble import hci
from bumble.device import Connection, Device, ChannelSoundingCapabilities
from bumble.transport import open_transport
import bumble.logging


# From https://cs.android.com/android/platform/superproject/main/+/main:packages/modules/Bluetooth/system/gd/hci/distance_measurement_manager.cc.
CS_TONE_ANTENNA_CONFIG_MAPPING_TABLE = [
    [0, 4, 5, 6],
    [1, 7, 7, 7],
    [2, 7, 7, 7],
    [3, 7, 7, 7],
]
CS_PREFERRED_PEER_ANTENNA_MAPPING_TABLE = [1, 1, 1, 1, 3, 7, 15, 3]
CS_ANTENNA_PERMUTATION_ARRAY = [
    [1, 2, 3, 4],
    [2, 1, 3, 4],
    [1, 3, 2, 4],
    [3, 1, 2, 4],
    [3, 2, 1, 4],
    [2, 3, 1, 4],
    [1, 2, 4, 3],
    [2, 1, 4, 3],
    [1, 4, 2, 3],
    [4, 1, 2, 3],
    [4, 2, 1, 3],
    [2, 4, 1, 3],
    [1, 4, 3, 2],
    [4, 1, 3, 2],
    [1, 3, 4, 2],
    [3, 1, 4, 2],
    [3, 4, 1, 2],
    [4, 3, 1, 2],
    [4, 2, 3, 1],
    [2, 4, 3, 1],
    [4, 3, 2, 1],
    [3, 4, 2, 1],
    [3, 2, 4, 1],
    [2, 3, 4, 1],
]


# -----------------------------------------------------------------------------
async def main() -> None:
    if len(sys.argv) < 3:
        print(
            'Usage: run_channel_sounding.py <config-file> <transport-spec-for-device>'
            '[target_address](If missing, run as reflector)'
        )
        print('example: run_channel_sounding.py cs_reflector.json usb:0')
        print(
            'example: run_channel_sounding.py cs_initiator.json usb:0 F0:F1:F2:F3:F4:F5'
        )
        return

    print('<<< connecting to HCI...')
    async with await open_transport(sys.argv[2]) as hci_transport:
        print('<<< connected')

        device = Device.from_config_file_with_hci(
            sys.argv[1], hci_transport.source, hci_transport.sink
        )
        await device.power_on()
        assert (local_cs_capabilities := device.cs_capabilities)

        if len(sys.argv) == 3:
            print('<<< Start Advertising')
            await device.start_advertising(
                own_address_type=hci.OwnAddressType.RANDOM, auto_restart=True
            )

            def on_cs_capabilities(
                connection: Connection, capabilities: ChannelSoundingCapabilities
            ):
                del capabilities
                print('<<< Set CS Settings')
                asyncio.create_task(device.set_default_cs_settings(connection))

            device.on(
                'connection',
                lambda connection: connection.on(
                    'channel_sounding_capabilities',
                    functools.partial(on_cs_capabilities, connection),
                ),
            )
        else:
            target_address = hci.Address(sys.argv[3])

            print(f'<<< Connecting to {target_address}')
            connection = await device.connect(
                target_address, transport=core.PhysicalTransport.LE
            )
            print('<<< ACL Connected')
            if not (await device.get_long_term_key(connection.handle, b'', 0)):
                print('<<< No bond, start pairing')
                await connection.pair()
                print('<<< Pairing complete')

            print('<<< Encrypting Connection')
            await connection.encrypt()

            print('<<< Getting remote CS Capabilities...')
            remote_capabilities = await device.get_remote_cs_capabilities(connection)
            print('<<< Set CS Settings...')
            await device.set_default_cs_settings(connection)
            print('<<< Set CS Config...')
            config = await device.create_cs_config(connection)
            print('<<< Enable CS Security...')
            await device.enable_cs_security(connection)
            tone_antenna_config_selection = CS_TONE_ANTENNA_CONFIG_MAPPING_TABLE[
                local_cs_capabilities.num_antennas_supported - 1
            ][remote_capabilities.num_antennas_supported - 1]
            print('<<< Set CS Procedure Parameters...')
            await device.set_cs_procedure_parameters(
                connection=connection,
                config=config,
                tone_antenna_config_selection=tone_antenna_config_selection,
                preferred_peer_antenna=CS_PREFERRED_PEER_ANTENNA_MAPPING_TABLE[
                    tone_antenna_config_selection
                ],
            )
            print('<<< Enable CS Procedure...')
            await device.enable_cs_procedure(connection=connection, config=config)

        await hci_transport.source.terminated


# -----------------------------------------------------------------------------
bumble.logging.setup_basic_logging('DEBUG')
asyncio.run(main())