Change device name during BLE Connection (SDK 15.0.0)

[leoc7]

Hi everyone,

My hw/sw configuration:

- nRF52840
- sdk 15.0.0
- softdevice: s140_nrf52_6.0.0

I would like to change the device name and update it in advertising packet, during a BLE connection.

void change_ble_device_name(uint8_t *device_name){
    ble_gap_conn_sec_mode_t sec_mode;
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    uint32_t err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *)device_name,
                                          strlen(device_name));
    APP_ERROR_CHECK(err_code);

    /* Re-initialize advertising module */
    advertising_init();

    /* Start advertising */
    ble_advertising_start(&m_advertising, BLE_ADV_MODE_FAST);
    APP_ERROR_CHECK(err_code);

    NRF_LOG_DEBUG("Ble name changed");
}

Reading this post: 

https://devzone.nordicsemi.com/f/nordic-q-a/21702/renaming-device

I discovered that is sufficient to change device name using sd_ble_gap_device_name_set and re-init the advertising.

My advertising function:

static void advertising_init(void)
{
    ret_code_t             err_code;
    ble_advertising_init_t init;

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

    /* Advertising Data */
    init.advdata.name_type               = BLE_ADVDATA_FULL_NAME; 						
    init.advdata.flags                   = BLE_GAP_ADV_FLAGS_LE_ONLY_GENERAL_DISC_MODE; 

    /* Scan Response Data */
    init.srdata.uuids_complete.uuid_cnt  = sizeof(m_adv_uuids) / sizeof(m_adv_uuids[0]); 
    init.srdata.uuids_complete.p_uuids   = m_adv_uuids;

    init.config.ble_adv_fast_enabled  	 = true;
    init.config.ble_adv_fast_interval 	 = APP_ADV_INTERVAL;
    init.config.ble_adv_fast_timeout     = APP_ADV_DURATION;

    init.evt_handler = on_adv_evt;

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

    ble_advertising_conn_cfg_tag_set(&m_advertising, APP_BLE_CONN_CFG_TAG);
}

I tried this solution, but It doesn't work and ble_advertising_init returns NO error.

I spent a lot of time surfing Nordic DevZone forum, but I didn't find a working solution.

Could you help me, please?

Thanks

[Pertti Kasanen]

I remember solving that once but not 100% of the complex details.

I think it included calling first sd_ble_gap_device_name_set(), then sd_ble_gap_adv_stop() and then

[edit:] ble_advertising_init().

[leoc7]

I don't understand your solution.
What is seed_advertising_init() function?

I tried to
- change name

- stop adv

- re-init advertising

But when you disconnect from device, device stops to advertise.

[Pertti Kasanen]

Sorry, edited that. I thought I had that edited before posting but failed somehow :(

Changing the advertising packet content on the fly is a complex task - with everything that is needed around. We use SDK 15.2.0 and it is already different than SDK15.0. Cannot remember how we had it implemented on the 15.0. 15.2 has additional functions for the task - but it is more complex. 

With default setup you device stops advertising already when you connect. You need to catch the disconnect event and restart the advertising. 

[leoc7]

I think I've solved it

I modified change_ble_device_name function in this way:

void change_ble_device_name(uint8_t *device_name){
    ble_gap_conn_sec_mode_t sec_mode;
    BLE_GAP_CONN_SEC_MODE_SET_OPEN(&sec_mode);

    /* Change device name */
    uint32_t err_code = sd_ble_gap_device_name_set(&sec_mode,
                                          (const uint8_t *)device_name,
                                          strlen(device_name));
    APP_ERROR_CHECK(err_code);

    /* Store Current connection state od adv lib */
    uint16_t m_adv_current_slave_link_conn_handle_saved = m_advertising.current_slave_link_conn_handle;

    /* Re-initialize advertising module */
    advertising_init();

    /* Re-store Current connection state lib */
    m_advertising.current_slave_link_conn_handle = m_adv_current_slave_link_conn_handle_saved;
}

I saved current_slave_link_conn_handle variable, because adv init function set current_slave_link_conn_handle to BLE_CONN_HANDLE_INVALID.

uint32_t ble_advertising_init(ble_advertising_t            * const p_advertising,
                              ble_advertising_init_t const * const p_init)
{
//...
    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;
//...
}

Setting current_slave_link_conn_handle to BLE_CONN_HANDLE_INVALID, on_disconnected function inside ble_advertising.c, doesn't restart advertising.

static void on_disconnected(ble_advertising_t * const p_advertising, ble_evt_t const * p_ble_evt)
{
    uint32_t ret;

    p_advertising->whitelist_temporarily_disabled = false;

    if (p_ble_evt->evt.gap_evt.conn_handle == p_advertising->current_slave_link_conn_handle &&
        p_advertising->adv_modes_config.ble_adv_on_disconnect_disabled == false)
    {
       ret = ble_advertising_start(p_advertising, BLE_ADV_MODE_DIRECTED_HIGH_DUTY);
       if ((ret != NRF_SUCCESS) && (p_advertising->error_handler != NULL))
       {
           p_advertising->error_handler(ret);
       }
    }
}