Updating Advertisement data in nrf52840 using SDK 16

[Akshay Goyal]

Hi,

I am trying to update my advertisement data as well as scan response data (i want to put some custom advertisement data and the device name in scan response data).

// Stop advertisement
err_code=sd_ble_gap_adv_stop(m_advertising.adv_handle);
APP_ERROR_CHECK(err_code);


// encoding BLE adv data
new_advdata.adv_data.len = BLE_GAP_ADV_SET_DATA_SIZE_MAX;
err_code = ble_advdata_encode(&init.advdata, new_advdata.adv_data.p_data, &new_advdata.adv_data.len);
APP_ERROR_CHECK(err_code);

// encoding BLE scan response data
new_advdata.scan_rsp_data.len = BLE_GAP_ADV_SET_DATA_SIZE_MAX;
err_code = ble_advdata_encode(&init.srdata, new_advdata.scan_rsp_data.p_data, &new_advdata.scan_rsp_data.len);
APP_ERROR_CHECK(err_code);

//configure advertisement
err_code= sd_ble_gap_adv_set_configure(&m_advertising.adv_handle, &new_advdata, &m_advertising.adv_params);
APP_ERROR_CHECK(err_code);

// start Advertisement
err_code = sd_ble_gap_adv_start(m_advertising.adv_handle, APP_BLE_CONN_CFG_TAG);
APP_ERROR_CHECK(err_code);

After populating ble_advertising_init_t this structure i am using this code, but ble_advdata_encode is returning error code 16.

[BardenDK]

Hi Akshay,

It is not clear if you use new buffers for each update of the advertisement data. This is necessary. Take a look at this code snippet, taken from mesh_adv.c from the MESH SDK:

/**
 * In the SoftDevice v6.0.0 API, the advertisement data buffers are owned by the application.
 * If we want to change the advertisement data while the advertiser is running, we need to double
 * buffer the data.
 */
static uint8_t m_advdata_raw[2][MESH_ADV_DATA_SIZE_MAX];
static uint8_t m_srdata_raw[2][MESH_ADV_DATA_SIZE_MAX];
static uint8_t m_adv_set_index;

void mesh_adv_data_set(uint16_t service_uuid, const uint8_t * p_service_data, uint8_t length)
{
    memset(&m_gap_adv_data, 0, sizeof(m_gap_adv_data));
    m_gap_adv_data.adv_data.p_data      = m_advdata_raw[m_adv_set_index];
    m_gap_adv_data.scan_rsp_data.p_data = m_srdata_raw[m_adv_set_index];
    m_gap_adv_data.adv_data.len         = sizeof(m_advdata_raw[0]);
    m_gap_adv_data.scan_rsp_data.len    = sizeof(m_srdata_raw[m_adv_set_index]);
    m_adv_set_index = (m_adv_set_index + 1) & 1;

    ble_advdata_t advdata;
    memset(&advdata, 0, sizeof(advdata));
    advdata.flags = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;

    ble_uuid_t uuids[] = {{service_uuid, BLE_UUID_TYPE_BLE}};
    advdata.uuids_complete.uuid_cnt = ARRAY_SIZE(uuids);
    advdata.uuids_complete.p_uuids = uuids;

    ble_advdata_service_data_t service_data;
    service_data.service_uuid = service_uuid;
    service_data.data.size = length;
    service_data.data.p_data = (uint8_t *) p_service_data;

    advdata.p_service_data_array = &service_data;
    advdata.service_data_count = 1;

    /* The application may freely set anything into the scan response data. */
    ble_advdata_t srdata;
    memset(&srdata, 0, sizeof(srdata));
    srdata.name_type = BLE_ADVDATA_FULL_NAME;

    APP_ERROR_CHECK(ble_advdata_encode(&advdata, m_gap_adv_data.adv_data.p_data, &m_gap_adv_data.adv_data.len));
    APP_ERROR_CHECK(ble_advdata_encode(&srdata, m_gap_adv_data.scan_rsp_data.p_data, &m_gap_adv_data.scan_rsp_data.len));

#if NRF_SD_BLE_API_VERSION >= 6

    uint32_t err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_gap_adv_data, &m_adv_params);
    if (err_code == NRF_ERROR_INVALID_STATE)
    {
        err_code = sd_ble_gap_adv_set_configure(&m_adv_handle, &m_gap_adv_data, NULL);
    }
#else

    uint32_t err_code = sd_ble_gap_adv_data_set(m_gap_adv_data.adv_data.p_data,
                                                m_gap_adv_data.adv_data.len,
                                                m_gap_adv_data.scan_rsp_data.p_data,
                                                m_gap_adv_data.scan_rsp_data.len);
#endif  /* NRF_SD_BLE_API_VERSION >= 6 */
    APP_ERROR_CHECK(err_code);
}

Hope this helps.