bleak.exc.BleakError: failed to discover services, device disconnected

[bisudw]

• bleak version: 0.21.1
• Python version: 3.10
• Operating System: Ubuntu
• BlueZ version (bluetoothctl -v) in case of Linux: 5.64

Description

I have a Vernier Caliper from TESA which has a BLE module and it gives data from that BLE Module. I am trying to read the data from the BLE Module. I am ble to read it in My Phone using LightBlue App (a ble scanner app).

What I Did

When I am rnning the Service_Explorer I am able to discover the device and the advertised service UUID is also visible. Its the same service UUID that i get in my phone app.

It looks like this:

E0:4B:16:4A:55:EA: TLC-BLE
--------------------------
AdvertisementData(local_name='TLC-BLE', manufacturer_data={1341: b'\x0800530322\x069E0445'}, service_uuids=['6e400001-b5a3-f393-e0a9-e50e24dcca9e'], tx_power=4, rssi=-49)

But when I am trying to connect to the same BLE device I am getting error which says:

bleak.exc.BleakError: failed to discover services, device disconnected

here is the code which I am using to trying to connect:

import asyncio
from bleak import BleakClient


async def main():
    async with BleakClient("E0:4B:16:4A:55:EA") as client:
        # Read a characteristic, etc.
        print("Connected")

    # Device will disconnect when block exits.
    print("disconnect")

# Using asyncio.run() is important to ensure that device disconnects on
# KeyboardInterrupt or other unhandled exception.
asyncio.run(main())

Logs

Traceback (most recent call last):
  File "/home/biswa/PycharmProjects/BLEScanner/main.py", line 15, in <module>
    asyncio.run(main())
  File "/usr/lib/python3.10/asyncio/runners.py", line 44, in run
    return loop.run_until_complete(main)
  File "/usr/lib/python3.10/asyncio/base_events.py", line 649, in run_until_complete
    return future.result()
  File "/home/biswa/PycharmProjects/BLEScanner/main.py", line 6, in main
    async with BleakClient("E0:4B:16:4A:55:EA") as client:
  File "/home/biswa/PycharmProjects/BLEScanner/.venv/lib/python3.10/site-packages/bleak/__init__.py", line 565, in __aenter__
    await self.connect()
  File "/home/biswa/PycharmProjects/BLEScanner/.venv/lib/python3.10/site-packages/bleak/__init__.py", line 605, in connect
    return await self._backend.connect(**kwargs)
  File "/home/biswa/PycharmProjects/BLEScanner/.venv/lib/python3.10/site-packages/bleak/backends/bluezdbus/client.py", line 268, in connect
    await self.get_services(
  File "/home/biswa/PycharmProjects/BLEScanner/.venv/lib/python3.10/site-packages/bleak/backends/bluezdbus/client.py", line 656, in get_services
    self.services = await manager.get_services(
  File "/home/biswa/PycharmProjects/BLEScanner/.venv/lib/python3.10/site-packages/bleak/backends/bluezdbus/manager.py", line 644, in get_services
    await self._wait_for_services_discovery(device_path)
  File "/home/biswa/PycharmProjects/BLEScanner/.venv/lib/python3.10/site-packages/bleak/backends/bluezdbus/manager.py", line 779, in _wait_for_services_discovery
    raise BleakError("failed to discover services, device disconnected")
bleak.exc.BleakError: failed to discover services, device disconnected

[dlech]

Can you run the same program with debug logging enabled? If that doesn't provide enough info you may need to log Bluetooth packets as well.

https://bleak.readthedocs.io/en/latest/troubleshooting.html