Is it important to first add the advertising service UUID?

[Christopher Hunt]

Given a peripheral with BLE services A and B, if I advertise B but add A first during my services_init code, then the 16 bit UUID portion of B is added to A's long UUID. Is this intended behaviour i.e. should the service to be advertised always be added first? Certainly, if I add B first then the advertising UUID is correct.

[Jared]

Hi,

 Is B a predefined service and is A a custom service? What are you using as a base UUID? Could you provide some code that shows where you set the UUID of B and A and any base UUID if it's used. I need a better overview over what you're actually doing. 

regards

Jared 

[mrono]

This sounds familiar. Could it be similar to this case?

[Jared]

Thank you for sharing this thread. It might very well be similar to that case. 

[Christopher Hunt]

Both A and B are custom services.

Here's how my UUIDs are declared (relevant portions are shown only):

// UUID eba38534-0bcb-4b34-85a3-85b9744ccc5f
#define A_SERVICE_UUID_BASE                                                                   \
    {                                                                                                  \
        0x5f, 0xcc, 0x4c, 0x74, 0xb9, 0x85, 0xa3, 0x85, 0x34, 0x4b, 0xcb, 0x0b, 0x34, 0x85, 0xa3, 0xeb \
    }

#define A_SERVICE_UUID 0x8534

// UUID 148d12e2-a31e-4117-b763-403cc42efa61
#define B_SERVICE_UUID_BASE                                                               \
    {                                                                                                  \
        0x61, 0xfa, 0x2e, 0xc4, 0x3c, 0x40, 0x63, 0xb7, 0x17, 0x41, 0x1e, 0xa3, 0xe2, 0x12, 0x8d, 0x14 \
    }

#define B_SERVICE_UUID 0x12e2

static ble_uuid_t m_adv_uuids[] = /**< Universally unique service identifiers. */
    {{B_SERVICE_UUID, BLE_UUID_TYPE_VENDOR_BEGIN}};

...

    // Add A Service UUID
    ble_uuid128_t base_uuid = {A_SERVICE_UUID_BASE};
    err_code = sd_ble_uuid_vs_add(&base_uuid, &p_a->uuid_type);
    VERIFY_SUCCESS(err_code);

    ble_uuid.type = p_a->uuid_type;
    ble_uuid.uuid = A_SERVICE_UUID;

    // Add the Service
    err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY, &ble_uuid, &p_a->service_handle);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }

...

    // Add B Service UUID
    ble_uuid128_t base_uuid = {B_SERVICE_UUID_BASE};
    err_code = sd_ble_uuid_vs_add(&base_uuid, &p_b->uuid_type);
    VERIFY_SUCCESS(err_code);

    ble_uuid.type = p_b->uuid_type;
    ble_uuid.uuid = B_SERVICE_UUID;

    // Add the Service
    err_code = sd_ble_gatts_service_add(BLE_GATTS_SRVC_TYPE_PRIMARY, &ble_uuid, &p_b->service_handle);
    if (err_code != NRF_SUCCESS)
    {
        return err_code;
    }

[Christopher Hunt]

I'm not sure that they are the same issue as I'm using two custom services (a point of difference).