BLE connects but connection is lost immediately

[salvoaerodev]

I wrote a simple script to discover a device with a fixed adv complete name, and connect to this device with his MAC address. After found it i need to connect to that device and discover services and characteristics, but after the connection i get a GATT object and connection closes when i try to discover his services.

I verified the connection on my BLE device. The connection started normally. Anyway when i call the

bluetooth.isconnected()

it fails and on my console i do not get the error message i wrote for that condition.

The full code i wrote is here

import binascii
from network import Bluetooth
bluetooth = Bluetooth()
bluetooth.start_scan(10)    # start scanning with no timeout
while bluetooth.isscanning():
    adv = bluetooth.get_adv()
    if(adv != None):
        name = bluetooth.resolve_adv_data(adv.data, Bluetooth.ADV_NAME_CMPL)
        print(name)
        if(name == 'xDev-FF:A1:B0-M01'):
            mac_address = binascii.hexlify(adv.mac)
            print("MAC: "+ str(mac_address))
            print("DATA: {}".format(binascii.hexlify(adv.data)))
            conn = bluetooth.connect(adv.mac)
            if(conn.isconnected()):
                print("Connection opened!")
            print("Connected to device with addr = {}".format(binascii.hexlify(adv.mac)))
            services = conn.services()
            print("Service List")
            for service in services:
                time.sleep(0.050)
                print(service)

And here the log

xDev-FF:A1:B0-M01
MAC: b'f10403020100'
DATA: b'020106120978444f4d2d46463a41313a42302d4d3031020afe000000000000'
Connected to device with addr = b'f10403020100'
Traceback (most recent call last):
  File "<stdin>", line 18, in <module>
OSError: connection already closed

[Arkaik]

Hi, I had the same problem, which firmware version are you using?

Personnaly I was using 1.6.12.b1.
Following this topic I found that downgrading to 1.4.0.b1 works.

Hope it helps.

[salvoaerodev]

It's your same firmware @Arkaik, so probably it's a bug introduced with 1.6.12.b1. I will try to downgrade too. Thanks for your support and let's keep in touch for next updates on BLE.

[Arkaik]

@salvoaerodev Sure, I hope this bug will be fixed soon as it could be nice to reupgrade firmware for already fixed bugs.