examples/heart_rate_server.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.

import asyncio
import math
import random

# -----------------------------------------------------------------------------
# Imports
# -----------------------------------------------------------------------------
import sys
import time

import bumble.logging
from bumble import data_types
from bumble.core import AdvertisingData
from bumble.device import Device
from bumble.profiles.device_information_service import DeviceInformationService
from bumble.profiles.heart_rate_service import HeartRateService
from bumble.transport import open_transport
from bumble.utils import AsyncRunner


# -----------------------------------------------------------------------------
async def main() -> None:
    if len(sys.argv) != 3:
        print('Usage: python heart_rate_server.py <device-config> <transport-spec>')
        print('example: python heart_rate_server.py device1.json usb:0')
        return

    async with await open_transport(sys.argv[2]) as hci_transport:
        device = Device.from_config_file_with_hci(
            sys.argv[1], hci_transport.source, hci_transport.sink
        )

        # Keep track of accumulated expended energy
        energy_start_time = time.time()

        def reset_energy_expended():
            nonlocal energy_start_time
            energy_start_time = time.time()

        # Add a Device Information Service and Heart Rate Service to the GATT sever
        device_information_service = DeviceInformationService(
            manufacturer_name='ACME',
            model_number='HR-102',
            serial_number='7654321',
            hardware_revision='1.1.3',
            software_revision='2.5.6',
            system_id=(0x123456, 0x8877665544),
        )

        heart_rate_service = HeartRateService(
            read_heart_rate_measurement=lambda _: HeartRateService.HeartRateMeasurement(
                heart_rate=100 + int(50 * math.sin(time.time() * math.pi / 60)),
                sensor_contact_detected=random.choice((True, False, None)),
                energy_expended=random.choice(
                    (int((time.time() - energy_start_time) * 100), None)
                ),
                rr_intervals=random.choice(
                    (
                        (
                            random.randint(900, 1100) // 1000,
                            random.randint(900, 1100) // 1000,
                        ),
                        None,
                    )
                ),
            ),
            body_sensor_location=HeartRateService.BodySensorLocation.WRIST,
            reset_energy_expended=lambda _: reset_energy_expended(),
        )

        device.add_services([device_information_service, heart_rate_service])

        # Set the advertising data
        device.advertising_data = bytes(
            AdvertisingData(
                [
                    data_types.CompleteLocalName('Bumble Heart'),
                    data_types.IncompleteListOf16BitServiceUUIDs(
                        [heart_rate_service.uuid]
                    ),
                    data_types.Appearance(
                        data_types.Appearance.Category.HEART_RATE_SENSOR,
                        data_types.Appearance.HeartRateSensorSubcategory.GENERIC_HEART_RATE_SENSOR,
                    ),
                ]
            )
        )

        # Notify subscribers of the current value as soon as they subscribe
        def on_subscription(connection, notify_enabled, indicate_enabled):
            if notify_enabled or indicate_enabled:
                AsyncRunner.spawn(
                    device.notify_subscriber(
                        connection,
                        heart_rate_service.heart_rate_measurement_characteristic,
                    )
                )

        heart_rate_service.heart_rate_measurement_characteristic.on(
            'subscription', on_subscription
        )

        # Go!
        await device.power_on()
        await device.start_advertising(auto_restart=True)

        # Notify every 3 seconds
        while True:
            await asyncio.sleep(3.0)
            await device.notify_subscribers(
                heart_rate_service.heart_rate_measurement_characteristic
            )


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