examples/run_hfp_handsfree.py

# Copyright 2021-2022 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
# -----------------------------------------------------------------------------
import asyncio
import sys
import os
import logging
import json
import websockets
import functools
from typing import Optional

from bumble import rfcomm
from bumble import hci
from bumble.device import Device, Connection
from bumble.transport import open_transport_or_link
from bumble import hfp
from bumble.hfp import HfProtocol


# -----------------------------------------------------------------------------
class UiServer:
    protocol: Optional[HfProtocol] = None

    async def start(self):
        """Start a Websocket server to receive events from a web page."""

        async def serve(websocket, _path):
            while True:
                try:
                    message = await websocket.recv()
                    print('Received: ', str(message))

                    parsed = json.loads(message)
                    message_type = parsed['type']
                    if message_type == 'at_command':
                        if self.protocol is not None:
                            await self.protocol.execute_command(parsed['command'])

                except websockets.exceptions.ConnectionClosedOK:
                    pass

        # pylint: disable=no-member
        await websockets.serve(serve, 'localhost', 8989)


# -----------------------------------------------------------------------------
def on_dlc(dlc: rfcomm.DLC, configuration: hfp.Configuration):
    print('*** DLC connected', dlc)
    protocol = HfProtocol(dlc, configuration)
    UiServer.protocol = protocol
    asyncio.create_task(protocol.run())

    def on_sco_request(connection: Connection, link_type: int, protocol: HfProtocol):
        if connection == protocol.dlc.multiplexer.l2cap_channel.connection:
            if link_type == hci.HCI_Connection_Complete_Event.SCO_LINK_TYPE:
                esco_parameters = hfp.ESCO_PARAMETERS[
                    hfp.DefaultCodecParameters.SCO_CVSD_D1
                ]
            elif protocol.active_codec == hfp.AudioCodec.MSBC:
                esco_parameters = hfp.ESCO_PARAMETERS[
                    hfp.DefaultCodecParameters.ESCO_MSBC_T2
                ]
            elif protocol.active_codec == hfp.AudioCodec.CVSD:
                esco_parameters = hfp.ESCO_PARAMETERS[
                    hfp.DefaultCodecParameters.ESCO_CVSD_S4
                ]
            connection.abort_on(
                'disconnection',
                connection.device.send_command(
                    hci.HCI_Enhanced_Accept_Synchronous_Connection_Request_Command(
                        bd_addr=connection.peer_address, **esco_parameters.asdict()
                    )
                ),
            )

    handler = functools.partial(on_sco_request, protocol=protocol)
    dlc.multiplexer.l2cap_channel.connection.device.on('sco_request', handler)
    dlc.multiplexer.l2cap_channel.once(
        'close',
        lambda: dlc.multiplexer.l2cap_channel.connection.device.remove_listener(
            'sco_request', handler
        ),
    )


# -----------------------------------------------------------------------------
async def main():
    if len(sys.argv) < 3:
        print('Usage: run_classic_hfp.py <device-config> <transport-spec>')
        print('example: run_classic_hfp.py classic2.json usb:04b4:f901')
        return

    print('<<< connecting to HCI...')
    async with await open_transport_or_link(sys.argv[2]) as (hci_source, hci_sink):
        print('<<< connected')

        # Hands-Free profile configuration.
        # TODO: load configuration from file.
        configuration = hfp.Configuration(
            supported_hf_features=[
                hfp.HfFeature.THREE_WAY_CALLING,
                hfp.HfFeature.REMOTE_VOLUME_CONTROL,
                hfp.HfFeature.ENHANCED_CALL_STATUS,
                hfp.HfFeature.ENHANCED_CALL_CONTROL,
                hfp.HfFeature.CODEC_NEGOTIATION,
                hfp.HfFeature.HF_INDICATORS,
                hfp.HfFeature.ESCO_S4_SETTINGS_SUPPORTED,
            ],
            supported_hf_indicators=[
                hfp.HfIndicator.BATTERY_LEVEL,
            ],
            supported_audio_codecs=[
                hfp.AudioCodec.CVSD,
                hfp.AudioCodec.MSBC,
            ],
        )

        # Create a device
        device = Device.from_config_file_with_hci(sys.argv[1], hci_source, hci_sink)
        device.classic_enabled = True

        # Create and register a server
        rfcomm_server = rfcomm.Server(device)

        # Listen for incoming DLC connections
        channel_number = rfcomm_server.listen(lambda dlc: on_dlc(dlc, configuration))
        print(f'### Listening for connection on channel {channel_number}')

        # Advertise the HFP RFComm channel in the SDP
        device.sdp_service_records = {
            0x00010001: hfp.sdp_records(0x00010001, channel_number, configuration)
        }

        # Let's go!
        await device.power_on()

        # Start being discoverable and connectable
        await device.set_discoverable(True)
        await device.set_connectable(True)

        # Start the UI websocket server to offer a few buttons and input boxes
        ui_server = UiServer()
        await ui_server.start()

        await hci_source.wait_for_termination()


# -----------------------------------------------------------------------------
logging.basicConfig(level=os.environ.get('BUMBLE_LOGLEVEL', 'DEBUG').upper())
asyncio.run(main())