Unable to connect to device on Ubuntu

[xsaahil]

• bleak version: 0.11.0
• Python version: 3.8.10
• Operating System: Ubuntu 20.04.3
• BlueZ version (bluetoothctl -v) in case of Linux: 5.53

Description

I am trying to connect to a BLE Server to do some GATT operations such as reads and writes. When I am trying to connect to the device I am always getting this error:

bleak.exc.BleakDBusError: org.bluez.Error.NotAvailable

The laptop connects to the device and disconnects immediately and returns error.

What I Did

I tried connecting directly with bluetoothctl connect XX:XX:XX:XX:XX and this command is able to connect to the device and the connection is stable until I disconnect.

Currently, this things happen:

• When I run the script, the laptops BLE connects to the device
• After like 500 to 600 ms the laptop, this error shows up.

File "/home/user/venv/lib/python3.8/site-packages/bleak/backends/bluezdbus/utils.py", line 24, in assert_reply raise BleakDBusError(reply.error_name)
bleak.exc.BleakDBusError: org.bluez.Error.NotAvailable

• This is the how the object looks like that hits the exception and disconnects:

{'destination': ':1.368', 'path': None, 'interface': None, 'member': None, 'message_type': <MessageType.ERROR: 3>, 'flags': <MessageFlag.NO_REPLY_EXPECTED: 1>, 'error_name': 'org.bluez.Error.NotAvailable', 'reply_serial': 6, 'sender': ':1.303', 'unix_fds': [], 'signature': 's', 'signature_tree': <dbus_next.signature.SignatureTree object at 0x7fc57f7e9df0>, 'body': ['Operation currently not available'], 'serial': 3227}

I have tried reproducing this on a different laptop and the same thing hapens, I have also tried changing the bluez version from 5.53 to 5.45 and it still results the same.

[dlech]

• bleak version: 0.11.0

Please try with Bleak 0.13.0. This should include more information in the error message.

[xsaahil]

I have updated the version to 0.13.0 and this the error message:

{'destination': ':1.449', 'path': None, 'interface': None, 'member': None, 'message_type': <MessageType.ERROR: 3>, 'flags': <MessageFlag.NO_REPLY_EXPECTED: 1>, 'error_name': 'org.bluez.Error.NotAvailable', 'reply_serial': 6, 'sender': ':1.441', 'unix_fds': [], 'signature': 's', 'signature_tree': <dbus_next.signature.SignatureTree object at 0x7fde31e9ef40>, 'body': ['Operation currently not available'], 'serial': 326}

I have tried using pygatt and it works and keeps the connection, but the connection does not stay with bleak.

[dlech]

Looking at the BlueZ source code, it seems like this error comes from is an audio profile. Is this a dual-mode device (low energy + classic)?

There isn't a BlueZ API to only connect to low energy, so I'm afraid we probably can't fix this in Bleak.

You could try opening an issue in the BlueZ repository to see if they can offer more insight. Including logs from btmon there would probably be helpful.