Using detection_callback with service UUID in MacOS 12.4

[damianjwilliams]

• bleak version: 0.15.1
• Python version: 3.8
• Operating System: MacOS 12.4 and Windows 10

Description

Describe what you were trying to get done.
Use detection_callback.py example with MacOS 12.4

Tell us what happened, what went wrong, and what you expected to happen.
I wish to read advertising data from an ESP32 peripheral using the detection_callback.py example, but no advertising data is displayed. I know that when using MacOS 12.4, service UUIDs need to be provided to read advertising data (as discussed extensively, but I am still struggling to get it to work.

What I Did

My ESP32 is set up as a server using the BLE_server example from Arduino. The ESP32 will intermittently broadcast advertising data including a service UUID (in this case, 4fafc201-1fb5-459e-8fcc-c5c9c331914b)

It all works as expected on my PC running Windows 10:
I use discover.py example to determine the ESP32 MAC address.
Output:
94:B9:7E:DA:7C:FE: Long name works now

then service_explorer.py to confirm the service UUID.
Ouput:

INFO:__main__:	[Characteristic] 00002a05-0000-1000-8000-00805f9b34fb (Handle: 2): Service Changed (indicate), Value: None
INFO:__main__:		[Descriptor] 00002902-0000-1000-8000-00805f9b34fb (Handle: 4): Client Characteristic Configuration) | Value: b'\x02\x00'
INFO:__main__:[Service] 00001800-0000-1000-8000-00805f9b34fb (Handle: 20): Generic Access Profile
INFO:__main__:	[Characteristic] 00002a00-0000-1000-8000-00805f9b34fb (Handle: 21): Device Name (read), Value: b'Long name works now'
INFO:__main__:	[Characteristic] 00002a01-0000-1000-8000-00805f9b34fb (Handle: 23): Appearance (read), Value: b'\x00\x00'
INFO:__main__:	[Characteristic] 00002aa6-0000-1000-8000-00805f9b34fb (Handle: 25): Central Address Resolution (read), Value: b'\x00'
INFO:__main__:[Service] 4fafc201-1fb5-459e-8fcc-c5c9c331914b (Handle: 40): Unknown
INFO:__main__:	[Characteristic] beb5483e-36e1-4688-b7f5-ea07361b26a8 (Handle: 41): Unknown (read,write), Value: b'Hello World says Neil'

The correct service UUID is given in the second to last line.
I can also see this service UUID using the BLE scanner app I have on my phone.

I can then run detection_callback.py with this service_uuid
(i.e. including scanner = BleakScanner(simple_callback, ["4fafc201-1fb5-459e-8fcc-c5c9c331914b"])).
Output:

2022-08-24 22:10:29,835 __main__ INFO: 94:B9:7E:DA:7C:FE RSSI: -62, AdvertisementData(service_uuids=['4fafc201-1fb5-459e-8fcc-c5c9c331914b'])
2022-08-24 22:10:29,842 __main__ INFO: 94:B9:7E:DA:7C:FE RSSI: -62, AdvertisementData(local_name='Long name works now', service_uuids=['4fafc201-1fb5-459e-8fcc-c5c9c331914b'])
2022-08-24 22:10:29,952 __main__ INFO: 94:B9:7E:DA:7C:FE RSSI: -62, AdvertisementData(local_name='Long name works now', service_uuids=['4fafc201-1fb5-459e-8fcc-c5c9c331914b'])
2022-08-24 22:10:29,961 __main__ INFO: 94:B9:7E:DA:7C:FE RSSI: -60, AdvertisementData(local_name='Long name works now', service_uuids=['4fafc201-1fb5-459e-8fcc-c5c9c331914b'])
2022-08-24 22:10:30,171 __main__ INFO: 94:B9:7E:DA:7C:FE RSSI: -60, AdvertisementData(local_name='Long name works now', service_uuids=['4fafc201-1fb5

Everything seems to be working on my PC. However when I use the same detection_callback.py script including the service UUID on my Mac, all I get is

(re)starting scanner
(re)starting scanner

Am I missing something obvious?

[dlech]

If you have a question, please start a discussion: /~https://github.com/hbldh/bleak/discussions

[damianjwilliams]

Oop, I accidentally posted the issue in the middle of writing it. I've updated it now.

[dlech]

I know that when using MacOS 12.4, service UUIDs need to be provided to read advertising data (as discussed extensively, but I am still struggling to get it to work.

Apple fixed the bug in 12.3, so it is no longer required.

Am I missing something obvious?

Not that I can see. I've confirmed it is also not working on 12.5.1. I wonder if Apple introduced a new bug?

As a workaround, you can just leave out the service uuids.

[dlech]

After trying it a few more times, it is working again (I also started the Packet Logger app in the meantime). Not sure what could have been the difference from the times when I was able to reproduce the issue.

[damianjwilliams]

I just updated my MacOS from 12.4 to 12.5.1 and it seems to be working now! Thanks for your help.