BLE and Wifi interference?

[Paco88]

Hi to everyone!
I noticeed a possible issue using, at the same time, BLE and wifi.
Once created a bluetooth object, if services are exposed, i can't make a socket connection, and also the ftp server has communication problem.
Instead if a bluetooth object is created without services no issue is arised.
In the following code i try to create 3 bluetooth services and after that, i try to make a mqtt broker connection.

wlan = WLAN()
wlan.init(mode = WLAN.STA, antenna = WLAN.EXT_ANT, channel = 11)
bt = Bluetooth()
id = str(ubinascii.hexlify(machine.unique_id(), ':'), 'utf-8')
bt.set_advertisement(name = 'X-DOM - '+id[9:17].upper())
bt.advertise(True)
bt.callback(trigger=Bluetooth.CLIENT_CONNECTED | Bluetooth.CLIENT_DISCONNECTED, handler=conn_cb)

srv_reset = bt.service(uuid=0x77777777, isprimary=True,  nbr_chars=2, start=True)
reset = srv_reset.characteristic(uuid = 0x11111111, properties = Bluetooth.PROP_WRITE, value = 0)
password = srv_reset.characteristic(uuid = 0x22222222, properties = Bluetooth.PROP_WRITE, value = 0)
password.callback(trigger=Bluetooth.CHAR_WRITE_EVENT,handler= func_password)
reset.callback(trigger=Bluetooth.CHAR_WRITE_EVENT,handler= func_reset)

srv_refresh = bt.service(uuid=0x88888888, isprimary=True,  nbr_chars=1, start=True)
refresh = srv_refresh.characteristic(uuid = 0x33333333, properties = Bluetooth.PROP_WRITE, value = 0)
refresh.callback(trigger=Bluetooth.CHAR_WRITE_EVENT,handler= func_refresh)

srv_config = bt.service(uuid=0x99999999, isprimary=True,  nbr_chars=4, start=True)
ch_nets = srv_config.characteristic(uuid=0x44444444, properties = Bluetooth.PROP_READ, value = 0)
ch_nets.callback(trigger=Bluetooth.CHAR_READ_EVENT, handler=func_scanning)
net_config = srv_config.characteristic(uuid=0x55555555, properties = Bluetooth.PROP_WRITE, value = 0)
net_config.callback(trigger=Bluetooth.CHAR_WRITE_EVENT, handler=func_net_cf)
mqtt_config = srv_config.characteristic(uuid=0x66666666, properties = Bluetooth.PROP_WRITE, value = 0)
mqtt_config.callback(trigger=Bluetooth.CHAR_WRITE_EVENT, handler=func_mqtt_cf)
notify_config = srv_config.characteristic(uuid=0x12345678, properties = Bluetooth.PROP_WRITE, value = 0)
notify_config.callback(trigger=Bluetooth.CHAR_WRITE_EVENT, handler=func_notify_cf)

client = MQTTClient(CLIENT_ID,server="projectxdom.co.uk",user=uid,password=pwd_mqtt)
client.set_callback(sub_cb)
if not client.connect(clean_session = True):
    client.subscribe('/rgbled/color')
    client.subscribe('PippoBaudo')

In the client.connect() the wipy return the error code OSError: -76

Instead the following code works fine

wlan = WLAN()
wlan.init(mode = WLAN.STA, antenna = WLAN.EXT_ANT, channel = 11)
bt = Bluetooth()
id = str(ubinascii.hexlify(machine.unique_id(), ':'), 'utf-8')
bt.set_advertisement(name = 'X-DOM - '+id[9:17].upper())
bt.advertise(True)
bt.callback(trigger=Bluetooth.CLIENT_CONNECTED | Bluetooth.CLIENT_DISCONNECTED, handler=conn_cb)
client = MQTTClient(CLIENT_ID,server="projectxdom.co.uk",user=uid,password=pwd_mqtt)
client.set_callback(sub_cb)
if not client.connect(clean_session = True):
    client.subscribe('/rgbled/color')
    client.subscribe('PippoBaudo')

Is it a bug, or my mistake?
Tnx

[Innocenzo]

@Paco88 I think that the INTERNAL ANTENNA and the EXTERNAL ANTENNA are too close and this can cause an interference.

[Paco88]

This may be a real problem...

[Innocenzo]

@Paco88 Someone like @robert-hh, @jmarcelino or @bucknall maybe know some other motivation

[duffo64]

Hi @Paco88

WiFi and BLE are on the same antenna and ESP32 controls access via coexistence (hardware or software).
I see that you are explicitly enabling external antenna. What happens if you try with the onboard antenna ?

Claudio

[Paco88]

@duffo64
Hi!
No difference with internal or external antenna.

[redimo]

Even with an External Antenna the BLE seems to have quite some problems. Sometimes it doesnt find anyhting at all.