Characteristic Discovery with 128bit UUID

[AlessandroADG]

Hi,

We are evaluating the possibility to connect our nRF52840 to another BLE device but we are facing issues with UUID Nordic handling strategy.

Quickly: 

• We have a central nRF and two pheripheral. The first is Nordic the second is system in production and we cannot change the SW.
• We created a custom service on the Nordic pheripheral and it works properly (characteristic discovered sendind data etc.)
• Later we tried to discovery the service on the second pheripheral.
  Second pheripheral has:
  • SERVICE UUID acbd3540-0211-4126-8c1f-45bcb7722f9e
  • CHAR_1 UUID acbd3540-0211-4126-8c1f-45bcb7722fA0
  • CHAR_2 UUID acbd3540-0211-4126-8c1f-45bcb7722fA1
  • CHAR_3 UUID acbd3540-0211-4126-8c1f-45bcb7722fA2

As you can see the other vendor is adopting the same Nordic strategy for UUID but on 00-01 octet instead of 12-13 octet as Nordic.

We added SERVICE UUID and CHAR_1 UUID to UUID List in the SD (sd_ble_uuid_vs_add(..) ) and we provide 0x3540 to ble_db_discovery_evt_register

It connects to the pheripheal but the discovery fail.
Here the log:

ble_db_disc: Starting discovery of service with UUID 0x3540 on connection handle 0x1

nrf_ble_gq: Adding item to the request queue

nrf_ble_gq: GATTC Primary Services Discovery Request

nrf_ble_gq: SD GATT procedure (2) succeeded on connection handle: 1

nrf_ble_gq: Processing the request queue...

ble_db_disc: Service UUID 0xB03E not found

Did someone solved a similar problem or someone from Nordic can support?

Alessandro

[Simonr]

Hi Alessandro

Yes, it should be possible as long as you reference the correct UUID tag (sd_ble_uuid_vs_add())as I mentioned in my last reply. 

Best regards,

Simon

[AlessandroADG]

Hi Simon,

happy to know it's possible.

Justo to be clear.

First of all I have to add the different UUID with sd_ble_uuid_vs_add() with something like this

So, I will add all my UUID128 (service and characteristics).

    err_code = sd_ble_uuid_vs_add(&ads_base_uuid, &p_ble_ads_c->uuid_type);

    VERIFY_SUCCESS(err_code);

Later I will have to register the UUID for the discovery event.

But here my question: I have to do it?

All the characteristic have the same 16bit UUID so I need to use the 128UUID.

Here the code I am using up to now. This function accept only 16UUID not 128UUID

    ads_uuid.type = p_ble_ads_c->uuid_type;
    ads_uuid.uuid = ADS_SERVICE_UUID;

    return ble_db_discovery_evt_register(&ads_uuid);

This is why I am asking your support.

Alessandro