RE: How to advertise a DYNAMIC name after the deprecation of BT_LE_ADV_CONN_NAME ?

Vidar Berg — Wed, 23 Oct 2024 12:19:21 GMT

Hello,

[quote user=""]the advertising data however you cannot reference bt_get_name() from ad[][/quote]

To enable dynamic updates of the ad[] struct, remove the const keyword. This allows the app to modify the advertisement payload and call bt_le_adv_update_data() to update it on the fly.

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

int main(void)
{
    
    int counter = 0;
	int len;
	uint8_t dev_name[BT_GAP_ADV_MAX_ADV_DATA_LEN];

    ...

	for (;;) {
		k_msleep(1000);
		len = sprintf(dev_name, "Hello_World_%d", counter);
		printk("New device name %s. Len %d\n", dev_name, len);
		err = bt_set_name(dev_name);
		if (err) {
			printk("bt_set_name() failed. (err %d)\n", err);
		}
		
		/* Update adv. payload with new device name */
		ad[1].data = dev_name;
		ad[1].data_len = len;
		ad[1].type = BT_DATA_NAME_COMPLETE;

		err = bt_le_adv_update_data(ad, ARRAY_SIZE(ad), NULL, 0);
		if (err) {
			printk("bt_le_adv_update_data() failed. (err %d)\n", err);
		}

		counter++;
	}
	return 0;
}

Best regards,

Vidar

Edit: Please note that bt_set_name() will update the device name in BT settings (NV storage) if CONFIG_BT_SETTINGS is enabled. This can result in excessive flash usage if the name is updated too frequently. In that case, you may want to update the name only in the advertisement payload, without updating the attribute table.