How to connect with direct advertising?

[Yoshihiro Goto]

I am implementing a central device using the nRF Connect SDK. I want to connect to a peripheral device using direct advertising, but the central device does not seem to recognize the direct advertising. How can I connect to a device using direct advertising?

In the nRF SDK, when receiving direct advertising, there was an event called "White list report", but there is no corresponding callback in the nRF Connect SDK. The source code is as follows, and I have looked at various sample projects for central devices, but they all seem to be similar.

static void scan_init(void)
{
	int err;

	const struct bt_le_scan_param scan_param = {
		.interval = SCAN_INTERVAL,      // 100msec
		.interval_coded = 0,
		.options = BT_LE_SCAN_OPT_FILTER_ACCEPT_LIST | BT_LE_SCAN_OPT_FILTER_DUPLICATE,
		.timeout = 0,
		.type = BT_HCI_LE_SCAN_PASSIVE,
		.window = SCAN_WINDOW,          // 50msec
		.window_coded = 0,
	};

	struct bt_scan_init_param scan_init = {
		.connect_if_match = false,
		.conn_param = BT_LE_CONN_PARAM_DEFAULT,
		.scan_param = &scan_param,
	};

	bt_scan_init(&scan_init);
	bt_scan_cb_register(&scan_cb);

	err = bt_scan_filter_add(BT_SCAN_FILTER_TYPE_UUID, BT_UUID_BAS);
	if (err) {
		LOG_ERR("Scanning filters cannot be set (err %d)", err);
		return;
	}

	err = bt_scan_filter_enable(BT_SCAN_UUID_FILTER, false);
	if (err) {
		LOG_ERR("Filters cannot be turned on (err %d)", err);
	}
}

[Einarh]

Hello

A BLE course was added to our Developer Academy recently, here is an exercise that deals with filter accept lists (which is what NCS calls whitelists):

https://academy.nordicsemi.com/topic/blefund-lesson-5-exercise-2/

Hopefully you will find this useful, let me know if you're still having problems.

Best regards,

Einar

[Yoshihiro Goto]

Thank you for your information.

I have read the web site and my understanding is you recommend using a filter accept list instead of directed advertising. right? I could not find any information on directed advertising above web site.

Please let me know if you know any information for direct advertising. Or should I not use directed advertising in NCS perhaps?

Best regards,

Yoshihiro Goto

[Einarh]

I assume you've already looked at this sample?:

https://docs.zephyrproject.org/latest/samples/bluetooth/direct_adv/README.html

If you're not able to make direct advertising work the way it is done here in your system, then I would recommend setting up a filter accept list instead yes.

You might also find the discussion here interesting:

https://github.com/zephyrproject-rtos/zephyr/pull/50340

-Einar

[Yoshihiro Goto]

I read through the links you gave me, but there was nothing about Directed Advertising.
After that I could connect Directed Advertising with some trial and error.
Therefore I will close this thread.
Thank you.

[tiva4c]

could you share with me how did you do that, i have the peer address, and i want to do the direct advertisement to that central only, the advertisement code is working, but connection is not getting established, maybe scanner is not able to see the advertisement, thanks in advance

[Yoshihiro Goto]

Sorry for late reply.

I made a blog to share code for directed advertising.

https://qiita.com/yoshihiro0709/items/3356318689e962a9a79f

This blog is written in Japanese, but you will get main.c and prj.conf for peripheral and central. You can also read the pages using translations such as DeepL if necessary. (Probably not necessary)

I hope this is of some help to you.

[tiva4c]

You are bonding first and then doing the direct advertisement, did you ever try direct advertisement without bonding to the central first, like writing the central address yourself, and then making a connection with the central? With your code, I am able to connect, but my requirement is to connect to the central at power up, so no time to bond first.