Pattern being ignored?

[Odud]

• Bleak: 0.21.1
• Python version: 3.12.0
• Operating System: Debian GNU/Linux 12 (bookworm) (Raspberry Pi)
• BlueZ version (bluetoothctl -v) in case of Linux: bluetoothctl: 5.66

Description

Trying to only scan for devices from a particular manufacturer, so I used what I thought was the correct argument to the scanner: async with BleakScanner(callback, bluez={"Pattern": "A4:C1:38"}) as scanner:

A4:C1:38 is the start of the MAC addresses that I am iterested in. However all devices seem to be passed back to the callback

[dlech]

It sounds like what you want is BleakScanner.find_device_by_filter().

FYI, filtering by address doesn't work on macOS, so if you were trying to make something that works cross platform, you should consider filters on something from the advertisement data instead.

[Odud]

That's equivalent to what I do at the moment - I was hoping to offload the filtering to BlueZ

Pete Barlow

On Wed, 8 Nov 2023, 00:02 David Lechner, @.***> wrote:

It sounds like what you want is BleakScanner.find_device_by_filter() https://bleak.readthedocs.io/en/latest/api/scanner.html#bleak.BleakScanner.find_device_by_filter .

FYI, filtering by address doesn't work on macOS, so if you were trying to make something that works cross platform, you should consider filters on something from the advertisement data instead.

— Reply to this email directly, view it on GitHub https://github.com/hbldh/bleak/issues/1447#issuecomment-1800537719, or unsubscribe https://github.com/notifications/unsubscribe-auth/ADXMVZYOYRKWFP6BJJ3FCKDYDLDXRAVCNFSM6AAAAAA7A6SMUWVHI2DSMVQWIX3LMV43OSLTON2WKQ3PNVWWK3TUHMYTQMBQGUZTONZRHE . You are receiving this because you authored the thread.Message ID: @.***>

[dlech]

If the device in question has a service UUID in the advertising data, you ca use the service_uuids keyword arg to BleakScanner() to offload filtering. Filtering by address (and pretty much anything else) can't be offloaded.

[filmkorn]

Unsure if this is relevant to this issue - but I found that on bluez the service_uuids argument is ignored and the callback is called on non-matching devices.

• Bleak: 0.21.1
• Python version: 3.11.7
• Operating System (uname -a): Linux raspberrypi 6.1.21-v8+ #1642 SMP PREEMPT Mon Apr 3 17:24:16 BST 2023 aarch64 GNU/Linux
• BlueZ version (bluetoothctl -v) in case of Linux: bluetoothctl: 5.66

Example:

import asyncio

from bleak import BleakScanner, AdvertisementData, BLEDevice

SERVICE_UUID = "0e140000-0af1-4582-a242-773e63054c68"


async def detection_callback(device: BLEDevice, advertisement_data: AdvertisementData):
    print(f"Found device: {device.address} (device.name)")
    print(f"Matches service UUID: {SERVICE_UUID in advertisement_data.service_uuids}")


async def discover():
    scanner = BleakScanner(
        detection_callback=detection_callback,
        use_bdaddr=False,
        service_uuids=[SERVICE_UUID],
    )

    await scanner.start()
    await asyncio.sleep(20)


asyncio.run(discover())

Results:

Found device: 68:27:37:56:DD:C3 - [AV] Samsung Soundbar MS650
Matches service UUID: False
Found device: 0A:9F:E3:B6:74:C9 - 0A-9F-E3-B6-74-C9
Matches service UUID: False
Found device: 00:1B:66:E0:80:F0 - MOMENTUM 3
Matches service UUID: False

This doesn't happen on Windows in my tests.

[dlech]

Unsure if this is relevant to this issue -

Not relevant, so i moved it to a new issue.