Bleak not disconnecting automatically when run and stopped/interrupted with PyCharm

• bleak version: 0.12.1
• Python version: 3.9
• Operating System: PopOS 21.04 (based on Ubuntu)
• BlueZ version (bluetoothctl -v) in case of Linux: 5.56

Description

I connect to my BLE hardware device using python3 and Bleak and I send a LED command every 5 seconds indefinitely. The device blinks its LEDs and answers back. It works perfectly. However, when I stop the code (I use Pycharm and I press the red stop button), the snippet never works again unless I reset the Bluetooth subsystem (systemctl restart bluetooth). It seems I am suffering from the issue in line #348 of client.py in master branch, which states something like " Otherwise BlueZ will keep the device connected even after Python exits". I think I can confirm this since, when I run the code again it comes up with the error “bleak.exc.BleakError: Device with address <my_mac_below> was not found.” It cannot be found because it is not advertising since it is still connected in the background 😦

Also, in my hardware device logging subsystem, I see Bleak never tells it to disconnect. My other apps with other frameworks automatically disconnect if code is no longer working. I have seen this issue around the forum but tested some of the suggestions (some of the branches are not existing anymore) and it does not seem to be solved. Maybe I am missing some parameters on BleakClient()? Gonna check issue #377 again meanwhile.

This seems a great project. Let me know if I can do some testing around all this.

What I Did

Please see my code example 😃 I simply activate notifications on UUID_C. Then I write commands on UUID_W.

import logging
import asyncio
import bleak.exc
from bleak import BleakClient, discover


logging.basicConfig(level=logging.INFO)
UUID_C = 'f0001132-0451-4000-b000-000000000000'
UUID_W = 'f0001131-0451-4000-b000-000000000000'
addr = '04:EE:03:6C:EF:30'


def notification_handler(_, data):
    print(data)


async def main(mac):
    try:
        disconnected_event = asyncio.Event()

        def disconnected_callback(client):
            print("Disconnected callback called!")
            disconnected_event.set()

        async with BleakClient(mac, disconnected_callback=disconnected_callback) as client:
            await client.start_notify(UUID_C, notification_handler)
            # this blinks some LEDs in my hardware device :)
            v = b'LED \r'
            while 1:
                await client.write_gatt_char(UUID_W, v)
                await asyncio.sleep(5)

    except bleak.exc.BleakError as ex:
        print('-- {}'.format(ex))


if __name__ == "__main__":
    asyncio.run(main(addr))

[dlech]

In order to make disconnecting work correctly after an unhandled exception, replace:

        loop = asyncio.get_event_loop()
        loop.run_until_complete(run(ADDRESS))

with

        asyncio.run(run(ADDRESS))

[dlech]

I just tried to reproduce the issue using a fresh install of:

PyCharm 2021.2.2 (Community Edition)
Build #PC-212.5284.44, built on September 14, 2021
Runtime version: 11.0.12+7-b1504.28 amd64
VM: OpenJDK 64-Bit Server VM by JetBrains s.r.o.
Linux 5.11.0-37-generic
GC: G1 Young Generation, G1 Old Generation
Memory: 750M
Cores: 8

Current Desktop: ubuntu:GNOME

and examples/disconnect_callback.py.

The device disconnected as expected when pressing the stop button in PyCharm. So I’m not sure why your PyCharm would be different.