Unable to change Bluetooth name with Zephyr

[BENBF]

Hello,

I'm trying to change Bluetooth name at runtime using Zephyr on the nRF700-DK. So for now I have a name defined with CONFIG_BT_DEVICE_NAME in my prj.conf that I tried to override using the following code (based on this ticket ). Unfortunately, my device always appears with the old name. Is something missing in my prj.conf file ?

static const struct bt_data sd[] = 
{
	BT_DATA_BYTES(BT_DATA_UUID128_ALL, MY_SERVICE_UUID),
};


static struct bt_data ad[] = 
{
	BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR), BT_LE_ADV_OPT_USE_NAME ),
	BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),
};

static void bt_ready(int err)
{
	if (err) 
	{
		printk("BLE init failed with error code %d\n", err);
		return;
	}
	//Configure connection callbacks
	bt_conn_cb_register(&conn_callbacks);

	//Initialize services
	err = hc_bt_nus_init();
	if(err){
		printk("Failed to init NUS service (err:%d)\n", err);
		return;
	}

	err = hc_ble_identity_init();
	if(err){
		printk("Failed to init Identity service (err:%d)\n", err);
		return;
	}

	bt_set_name(BLE_NAME);
	bt_le_adv_update_data(ad, ARRAY_SIZE(ad), sd, ARRAY_SIZE(sd));

	//Start advertising
	err = bt_le_adv_start(BT_LE_ADV_CONN, ad, ARRAY_SIZE(ad),
			      sd, ARRAY_SIZE(sd));
	if (err) 
	{
		printk("Advertising failed to start (err %d)\n", err);
		return;
	}

	printk("Advertising successfully started\n");

	k_sem_give(&ble_init_ok);
}

int hc_bt_init(){
    int err = 0;
    
    err = bt_enable(bt_ready);

    if (err) 
	{
		printk("BLE initialization failed\n");
		printk("Error is %d\n", err);
	}

	err = k_sem_take(&ble_init_ok, K_MSEC(500));

    if (!err) 
	{
		printk("Bluetooth initialized\n");
	} else 
	{
		printk("BLE initialization did not complete in time\n");
	}

	return err;
}

prj.conf :

CONFIG_NEWLIB_LIBC=y

#Global attroibutes
CONFIG_GPIO=y

#SPI attributes
CONFIG_SPI=y

#PWM attributes
CONFIG_NRFX_PWM0=y

#BLE attributes
CONFIG_BT=y
CONFIG_BT_NUS=y
CONFIG_BT_GATT_DYNAMIC_DB=y
CONFIG_BT_GATT_CLIENT=y
CONFIG_BT_DEBUG_LOG=y
CONFIG_BT_MAX_CONN=1
CONFIG_BT_L2CAP_TX_BUF_COUNT=5
CONFIG_BT_PERIPHERAL=y
CONFIG_BT_DEVICE_NAME="My_Device"
CONFIG_BT_DEVICE_APPEARANCE=962

CONFIG_HEAP_MEM_POOL_SIZE=2048
CONFIG_SYSTEM_WORKQUEUE_STACK_SIZE=2048

CONFIG_BT_DEVICE_NAME_DYNAMIC=y
CONFIG_BT_DEVICE_NAME_MAX=30

#Tests
CONFIG_NEWLIB_LIBC_FLOAT_PRINTF=y

Thank you,
Best regards

[BENBF]

[Update] Something I missed in this thread was the usage of the BT_LE_ADV_OPT_USE_NAME option, so I changed my code to

static void bt_ready(int err)
{
	if (err){
		printk("BLE init failed with error code %d\n", err);
		return;
	}

	struct bt_le_adv_param param;
	memcpy(&param, &BT_LE_ADV_CONN_NAME, sizeof(struct bt_le_adv_param));

	bt_set_name("BLETestName");


	//Configure connection callbacks
	bt_conn_cb_register(&conn_callbacks);

	//Initialize services
	err = hc_bt_nus_init();
	if(err){
		printk("Failed to init NUS service (err:%d)\n", err);
		return;
	}

	err = hc_ble_identity_init();
	if(err){
		printk("Failed to init Identity service (err:%d)\n", err);
		return;
	}

	//Start advertising
	err = bt_le_adv_start(&param, ad, ARRAY_SIZE(ad), sd, ARRAY_SIZE(sd));
	if (err) 
	{
		printk("Advertising failed to start (err %d)\n", err);
		return;
	}

	printk("Advertising successfully started\n");
	k_sem_give(&ble_init_ok);
}

as it appears that BT_LE_ADV_CONN_NAME is BT_LE_ADV_CONN with the addition of the mentioned option.

With this code, bt_le_adv_start() function returns -22 error.

Bluetooth advertising is working fine when I use BT_LE_ADV_CONN instead of BT_LE_ADV_CONN_NAME but it still advertise with the name defined by CONFIG_BT_DEVICE_NAME in prj.conf instead of my new name.

Thank you,
Regards

[BENBF]

It seems that BT_LE_ADV_CONN_NAME  option is not mandatory and that bt_le_adv_update_data() just need to be called after bt_le_adv_start()

[EDIT] It that behaviour depend on the used Bluetooth application, ly smartphone sees the new name but nRFConnect sees the old one...

[EDIT 2] : nRFConnect seems to use the name defined in the scan data instead of the advertising data, using my new name in the scan data seems to mitigate my issue

Regards