Enabling extended advertising with scannable advertising

RE: Enabling extended advertising with scannable advertising

Amanda Hsieh — Fri, 17 Nov 2023 19:48:05 GMT

See bt_le_ext_adv_set_data() from the API documentation:

If the advertising set has been configured for extended advertising, then the maximum data length is defined by the controller with the maximum possible of BT_GAP_ADV_MAX_EXT_ADV_DATA_LEN bytes.

This applies to the scan response packet as well.

-Amanda H.

RE: Enabling extended advertising with scannable advertising

Matthew — Thu, 16 Nov 2023 19:36:35 GMT

So, I cannot use the 'ad' payload for my extended advertisement but can I use the 'sd' payload?

Is the 'sd' payload limited to 31 bytes when extended advertising is enabled?

RE: Enabling extended advertising with scannable advertising

Amanda Hsieh — Thu, 16 Nov 2023 18:02:26 GMT

Hi,

[quote user="MattBurton"]Is your recommendation to have this extended advertising data on my 'sd' payload?[/quote]

No, they cannot be used at the same time. See bt_le_ext_adv_set_data() from the API documentation:

-Amanda H.

RE: Enabling extended advertising

Matthew — Wed, 15 Nov 2023 21:27:44 GMT

However, I am not attempting to be connectable and scannable?

I just want to have an extended advertisement and be scannable. Is to have extended advertising, to, in turn become connectable?

Is your recommendation to have this extended advertising data on my 'sd' payload? is this not limited to 31 bytes making it unusable for ext advertising? / How can I actually use an extended advertisement while being scannable?

RE: Enabling extended advertising

Amanda Hsieh — Wed, 15 Nov 2023 15:04:22 GMT

Hi,

You can not use both ad. data and scan response data concurrently when using the extended advertising feature. This is defined and limited by the Bluetooth spec.

Bluetooth Core Specification Version 5.3 | Vol 4, Part E section 7.8.53: LE Set Extended Advertising Parameters command (page 2450 in the Bluetooth Core Specification Version 5.3):

If extended advertising PDU types are being used (bit 4 = 0) then: The advertisement shall not be both connectable and scannable. High duty cycle directed connectable advertising (≤ 3.75 ms advertising interval) shall not be used (bit 3 = 0).

RE: Enabling extended advertising

Matthew — Wed, 15 Nov 2023 03:14:09 GMT

Which on further investigation I find the function

	if (ext_adv) {
		if ((scannable && ad_len) || (!scannable && sd_len)) 
		{
			return -ENOTSUP;
		}

Which then suggests that if I am to have an advertisement and be scannable, then extended advertising is not available?

So I should remove my advertisement? / advertisement length?

The multiple broadcast example gets around this by not being scannable as it seems, however I require information both on my advertisement packet and I require to be scannable so this does not seem like a plausible fix.

Am I not able to be scannnable and do extended advertising?

RE: Enabling extended advertising

Matthew — Tue, 14 Nov 2023 23:49:10 GMT

When the adv_params .options is: 'BT_LE_ADV_OPT_USE_IDENTITY | BT_LE_ADV_OPT_SCANNABLE | BT_LE_ADV_OPT_NOTIFY_SCAN_REQ | BT_LE_ADV_OPT_EXT_ADV'

The output is:

'*** Booting Zephyr OS build v3.3.99-ncs1 ***
I: SoftDevice Controller build revision:
I: e0 7e 2e c1 5e 05 85 23 |.~..^..#
I: 46 15 dc fa 8e 29 7d 70 |F....)}p
I: 10 93 a5 fc |....
I: HW Platform: Nordic Semiconductor (0x0002)
I: HW Variant: nRF52x (0x0002)
I: Firmware: Standard Bluetooth controller (0x00) Version 224.11902 Build 2231721665
I: Identity: DE:AD:BE:EF:22:22 (random)
I: HCI: version 5.4 (0x0d) revision 0x1077, manufacturer 0x0059
I: LMP: version 5.4 (0x0d) subver 0x1077
Failed setting adv data (err -134)
Failed to start advertising (err -134)
Synchronisation init failed (err -134)'

Indicating that the function 'bt_le_ext_adv_set_data(adv, ad, ARRAY_SIZE(ad), sd, ARRAY_SIZE(sd))' is causing an error.

RE: Enabling extended advertising

Amanda Hsieh — Tue, 14 Nov 2023 22:04:32 GMT

Hi,

The nRF Distance Measurement with Bluetooth LE discovery sample already supports extended advertising as https://github.com/nrfconnect/sdk-nrf/blob/main/samples/bluetooth/nrf_dm/prj.conf#L20

[quote user=""]However, when I attempt to add this functionality by including 'BT_LE_ADV_OPT_EXT_ADV' in the 'adv_params', along with 'BT_LE_ADV_OPT_USE_IDENTITY | BT_LE_ADV_OPT_SCANNABLE | BT_LE_ADV_OPT_NOTIFY_SCAN_REQ' I am faced with the zephyr error code '134'.[/quote]

134 means Not supported. Which function returned the error code?

Regards,
Amanda H.