Updating Advertising Service Data

[jloliveira]

Good afternoon,

I'm running advertising with a uint16_t service data associated with a 16-bit service UUID.

I would like to update the service data regularly without the need to update the whole advertising package.

Is there a way to do this similarly to the flags_set() function in the BLE Advertising Module? When I try to accomplish it by recurring to "uint8_t * p_service_data = ble_advdata_parse(p_advertising->adv_data.adv_data.p_data, p_advertising->adv_data.adv_data.len, BLE_GAP_AD_TYPE_SERVICE_DATA)" I can never return the correct offset in the advertising data related to the Service Data field - it always returns 0 offset - and therefore can't access the actual Service Data to update it. Any suggestions to accomplish this?

Thank you,

João

[MartinBL]

Hi,

If ble_advdata_parse() always returns NULL it indicates that your advertising packets doesn't contain any Service Data. Have you confirmed that your packet actually contains a Service Data field before you call ble_advdata_parse()? You can easily see if the field is there with nRF Connect for mobile for example. 

If it is there, can you upload your code? 

[jloliveira]

Hi Martin,

Thank you for your reply.

I'm totally sure the advertising packet contains the ServiceData and it is working as expected. I'm updating the whole advertising data everytime I need to update the ServiceData and it works perfectly.

Any queues what might be wrong?

Thank you,

João

[MartinBL]

Not sure what it can be. Do you mind sharing your code? We can make the case private if you prefer confidentiality. 

[jloliveira]

Hi Martin,

I compiled the parts of code in respect to this matter for you to assess it.

Looking forward to hear any suggestion from you,

Thank you,

João

    //======= main.c =======
    
    static ble_advertising_init_t 		   m_init_adv_data_and_params;
 	static ble_advdata_service_data_t      m_service_data;
	uint16_t 							   m_sdata;
	static ble_uuid_t 					   m_adv_uuids[] = {{UUID_SERV_BEEP, BLE_UUID_TYPE_BLE}};
	static ble_gap_phys_t 				   m_phys;
	
    void advertising_init(void)
    {
    	uint32_t err_code;

    	//Build and Set Service Data
    	m_service_data.service_uuid       = UUID_SERV_BEEP;
    	m_service_data.data.size          = 2;
  
    	m_sdata                           = get_new_advertising_data();
    	m_service_data.data.p_data        = (uint8_t*)&m_sdata;


    	memset(&m_init_adv_data_and_params, 0, sizeof(m_init_adv_data_and_params));

    	//Build and Set Advertising Data.
    	m_init_adv_data_and_params.advdata.flags                        = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE;
    	m_init_adv_data_and_params.advdata.name_type                    = BLE_ADVDATA_FULL_NAME;
    	m_init_adv_data_and_params.advdata.include_appearance           = false;
    
    	m_init_adv_data_and_params.advdata.uuids_complete.uuid_cnt       = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]);
    	m_init_adv_data_and_params.advdata.uuids_complete.p_uuids        = m_adv_uuids;
    	m_init_adv_data_and_params.advdata.p_service_data_array          = &m_service_data;
    	m_init_adv_data_and_params.advdata.service_data_count            = 1;

    	//Build and Set Advertising Params.
    	m_init_adv_data_and_params.config.ble_adv_whitelist_enabled      = true;
    	m_init_adv_data_and_params.config.ble_adv_fast_enabled           = true;
    	m_init_adv_data_and_params.config.ble_adv_fast_interval          = APP_ADV_INTERVAL_FAST;
    	m_init_adv_data_and_params.config.ble_adv_fast_timeout           = APP_ADV_DURATION_10MS_FAST;
    	m_init_adv_data_and_params.config.ble_adv_slow_enabled           = true;
    	m_init_adv_data_and_params.config.ble_adv_slow_interval          = APP_ADV_INTERVAL_SLOW;
    	m_init_adv_data_and_params.config.ble_adv_slow_timeout           = APP_ADV_DURATION_10MS_SLOW;
    	m_init_adv_data_and_params.config.ble_adv_primary_phy            = BLE_GAP_PHY_1MBPS;
    	m_init_adv_data_and_params.config.ble_adv_secondary_phy          = BLE_GAP_PHY_1MBPS;


    	err_code = ble_advertising_init(&m_advertising, &m_init_adv_data_and_params);
    	APP_ERROR_CHECK(err_code);

    	ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
    }
    
    //====== ble_advertising.c =======
    
    uint32_t ble_advertising_init(ble_advertising_t            * const p_advertising,
                              ble_advertising_init_t const * const p_init)
	{
	
    	uint32_t ret;
    	if ((p_init == NULL) || (p_advertising == NULL))
    	{
    	    return NRF_ERROR_NULL;
    	}
    	if (!config_is_valid(&p_init->config))
    	{
    	    return NRF_ERROR_INVALID_PARAM;
    	}

    	p_advertising->adv_mode_current               = BLE_ADV_MODE_IDLE;
    	p_advertising->adv_modes_config               = p_init->config;
    	p_advertising->conn_cfg_tag                   = BLE_CONN_CFG_TAG_DEFAULT;
    	p_advertising->evt_handler                    = p_init->evt_handler;
    	//p_advertising->error_handler                = p_init->error_handler;
    	p_advertising->current_slave_link_conn_handle = BLE_CONN_HANDLE_INVALID;
    	p_advertising->p_adv_data                     = &p_advertising->adv_data;

    	memset(&p_advertising->peer_address, 0, sizeof(p_advertising->peer_address));

    	if (!p_advertising->initialized)
    	{
        	p_advertising->adv_handle = BLE_GAP_ADV_SET_HANDLE_NOT_SET;
    	}

    	uint16_t max_len = BLE_GAP_ADV_SET_DATA_SIZE_MAX;

    	ret = ble_advdata_encode(&p_init->advdata, p_advertising->enc_advdata, &max_len);
    	VERIFY_SUCCESS(ret);


    	p_advertising->adv_params.primary_phy     = BLE_GAP_PHY_1MBPS;
    	p_advertising->adv_params.duration        = p_advertising->adv_modes_config.ble_adv_fast_timeout;
    
    	p_advertising->adv_params.properties.type = BLE_GAP_ADV_TYPE_CONNECTABLE_SCANNABLE_UNDIRECTED;

    	p_advertising->adv_params.p_peer_addr     = NULL;
    	p_advertising->adv_params.filter_policy   = BLE_GAP_ADV_FP_ANY;
    	p_advertising->adv_params.interval        = p_advertising->adv_modes_config.ble_adv_fast_interval;

    	p_advertising->adv_params.scan_req_notification=true;

    	ret = sd_ble_gap_adv_set_configure(&p_advertising->adv_handle, NULL, &p_advertising->adv_params);
    	VERIFY_SUCCESS(ret);

    	p_advertising->initialized = true;

    	return ret;
	}
	
	ret_code_t sdata_set(ble_advertising_t * const p_advertising, uint16_t sdata)
	{
    	uint8_t * p_sdata = ble_advdata_parse(p_advertising->adv_data.adv_data.p_data,
                                          p_advertising->adv_data.adv_data.len,
                                          BLE_GAP_AD_TYPE_SERVICE_DATA);

    	if (p_sdata != NULL)
    	{
        	*p_sdata = sdata;
    	}
    	else //Debug
    	{
			uint16_t offset = 0;
        	ble_advdata_search(p_advertising->adv_data.adv_data.p_data, BLE_GAP_ADV_SET_DATA_SIZE_MAX, &offset, BLE_GAP_AD_TYPE_SERVICE_DATA);
        	NRF_LOG_INFO("OFFSET: %d", offset);
        }
        
    	return sd_ble_gap_adv_set_configure(&p_advertising->adv_handle, &p_advertising->adv_data, &p_advertising->adv_params);
	}

[MartinBL]

Hi,

What SDK are you using? I tried to use your advertising_init() and sdata_set() functions together with the ble_app_uart example in SDK 15 and it seems to work fine. ble_advdata_parse() returns the address of Service Data in the advertising packet and the offset is correct. When you call ble_advdata_parse(), can you check the value of p_advertising->adv_data.adv_data.len and make sure that it makes sense? Maybe the length has been altered somewhere and that your Service Data is "out of range".