how to dynamically change device_name on NCS?

RE: how to dynamically change device_name on NCS?

joe — Tue, 01 Feb 2022 01:52:01 GMT

thanks,I understand.

RE: how to dynamically change device_name on NCS?

Hung Bui — Mon, 31 Jan 2022 08:28:59 GMT

Hi Joe,

It's not allowed to have device name in both the advertising packet and the scan response packet.
So if you already declare adv_param.options |= BT_LE_ADV_OPT_USE_NAME, you should remove BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN) in the scan response.

Please note that you can step into the function bt_le_adv_start() to debug and check what cause the error.

RE: how to dynamically change device_name on NCS?

joe — Mon, 31 Jan 2022 04:31:35 GMT

Hi Hung:

I follow your code,it can update the device name successfully on peripheral_uart example.

for peripheral_hids_mouse example,

There are normal advertising and directed advertising,

I have the error at normal advertising (Advertising failed to start (err -22)")

I am not sure the error related to ad[] /sd[] or not.

if (!k_msgq_get(&bonds_queue, &addr, K_NO_WAIT)) {

...

int err = bt_le_adv_start(&adv_param, NULL, 0, NULL, 0); //Directed Advertising

} else

{
...

adv_param = *BT_LE_ADV_CONN;
adv_param.options |= BT_LE_ADV_OPT_ONE_TIME;
adv_param.options |= BT_LE_ADV_OPT_USE_NAME; //modify

bt_set_name("test_name"); //modify

err = bt_le_adv_start(&adv_param, ad, ARRAY_SIZE(ad), //normal Advertising
sd, ARRAY_SIZE(sd));

}

for peripheral_hids_mouse example ,its ad[] array and sd[] array are not same as peripheral_uart.

so I don't modify ad[] and sd[] .

my ad[] array as below

peripheral_hids_mouse:

static const struct bt_data ad[] = {
BT_DATA_BYTES(BT_DATA_GAP_APPEARANCE,
(CONFIG_BT_DEVICE_APPEARANCE >> 0) & 0xff,
(CONFIG_BT_DEVICE_APPEARANCE >> 8) & 0xff),
BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR)),
BT_DATA_BYTES(BT_DATA_UUID16_ALL,
0x12, 0x18, /* HID Service */
0x0f, 0x18), /* Battery Service */
};

static const struct bt_data sd[] = {
BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),
};

best regards,

Joe

RE: how to dynamically change device_name on NCS?

Hung Bui — Thu, 27 Jan 2022 13:35:12 GMT

Hi Joe,

I assume you are not trying to put the name into the Directed Advertising packet but it's the normal advertising you are asking about.

Please show what's in your ad[] array.
The following code worked for me:

	static const 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),
};

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

	err=bt_set_name("test_name");
	if (err) {
		LOG_ERR("Setname failed(err %d)", err);
		return;
	}
	err = bt_le_adv_start(BT_LE_ADV_CONN_NAME, ad, ARRAY_SIZE(ad), sd,
			      ARRAY_SIZE(sd));
	if (err) {
		LOG_ERR("Advertising failed to start (err %d)", err);
		return;
	}

Note that I have to remove the

BT_DATA(BT_DATA_NAME_COMPLETE, DEVICE_NAME, DEVICE_NAME_LEN),

inside the ad[] packet because it's already covered in the advertising option to use name.
Also if it's already advertising, and you change the name, you need to call

err = bt_le_adv_update_data( ad, ARRAY_SIZE(ad), sd,

ARRAY_SIZE(sd));

To update the device name.