aioble cannot retrieve device name

[eliclement]

When scanning for BLE devices the name() always returns None.
Using several BLE scanning apps I clearly see the advertised device names...
I am using an ESP32S3 and aioble

import aioble
import uasyncio as asyncio

async def scan():
    print("Scanning for BLE devices...")
    async with aioble.scan(duration_ms=20000) as scanner:
        async for result in scanner:
            name = result.name()
            print(f"Found device: {name}, RSSI: {result.rssi}")

asyncio.run(scan())

I get a list of found devices but no names could be retrieved by aioble.

Scanning for BLE devices...
Found device: None, RSSI: -38
Found device: None, RSSI: -80
Found device: None, RSSI: -52
Found device: None, RSSI: -44
Found device: None, RSSI: -54
Found device: None, RSSI: -37
Found device: None, RSSI: -81
Found device: None, RSSI: -42
Found device: None, RSSI: -63
Found device: None, RSSI: -77
Found device: None, RSSI: -51
Found device: None, RSSI: -71
Found device: None, RSSI: -36

[andrewleech]

Have you tried running the scan in active mode? Many Bluetooth devices place the device name in the response packet which means the slower active mode is needed.

Try adding active=True argument to the scan() function call.
https://github.com/micropython/micropython-lib/tree/68e3e07bc7ab63931cead3854b2a114e9a084248/micropython/bluetooth/aioble#usage

[eliclement]

@andrewleech I tried the actie=True but no success... Any other ideas?

import aioble
import uasyncio as asyncio

async def scan():
    print("Scanning for BLE devices...")
    async with aioble.scan(duration_ms=60000, active=True) as scanner:
        async for result in scanner:
            name = result.name()
            print(f"Found device: {name}, RSSI: {result.rssi}")

asyncio.run(scan())

Result is the same: result.name() returns always None. I also tried adding the interval_us=30000, window_us=30000 without success either.

[andrewleech]

I'm not sure sorry, it's been a few years since I used ble so I don't remember all the tricks.

The issue might be that the device names are being described differently than in the official name field, iirc the scanner apps on phone often create/display a fill-on device name based on features of the device.

What sort of device are you trying to scan for to get the name of? Can you give some examples of the things that aren't working?

[eliclement]

I am working on macOS and use the scanning applications: Bluetility or Lightblue. They both show me the correct name of any Android or iPhone in the surroundings for example. Using the library bleak on my mac or raspberry pi with the code below also shows the correct devices names in the surroundings:

import asyncio
from bleak import BleakScanner

async def scan_ble_devices():
    print("Scanning for BLE devices...")
    devices = await BleakScanner.discover()
    for device in devices:
        print(f"Device: {device.name}, Address: {device.address}, RSSI: {device.rssi}")

asyncio.run(scan_ble_devices())

Any other ideas where this misinterpretation can happen in the aioble device name handling?

[ekspla]

Correct me if there is something wrong in my comment below; I am not an expert in bluetooth.

Names of BLE peripheral devices seem to be not always advertised, while they can be obtained from
DEVICE INFORMATION SERVICE as written in the bluetooth spec.

Some sophisticated BLE stacks, like those in PCs and mobile phones, seem to store the name of
a peripheral device once they are connected to for the future use, while this is not the case in
Micropython.

[Additional comment]
An active scan does not necessarily gurantee that the name of the peripheral device is obtained.

While it requests a response with additional data, the response does not have to contain the name;
the response itself may not be delivered to the scanner.

If you want to investigate more in detail, I would suggest you to use a BLE sniffer.