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.

# -----------------------------------------------------------------------------
# Imports
# -----------------------------------------------------------------------------
import sys
import time
import math
import random
import struct
import logging
import asyncio
import os

from bumble.core import AdvertisingData
from bumble.device import Device
from bumble.transport import open_transport_or_link
from bumble.profiles.device_information_service import DeviceInformationService
from bumble.profiles.heart_rate_service import HeartRateService


# -----------------------------------------------------------------------------
async def main():
    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_or_link(sys.argv[2]) as (hci_source, hci_sink):
        device = Device.from_config_file_with_hci(sys.argv[1], hci_source, hci_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([
                (AdvertisingData.COMPLETE_LOCAL_NAME, bytes('Bumble Heart', 'utf-8')),
                (AdvertisingData.INCOMPLETE_LIST_OF_16_BIT_SERVICE_CLASS_UUIDS, bytes(heart_rate_service.uuid)),
                (AdvertisingData.APPEARANCE, struct.pack('<H', 0x0340))
            ])
        )

        # 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)


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