RE: Way to enumerate advertisements

Jakob Ruhe — Tue, 25 Feb 2025 13:26:48 GMT

I guess you should be able to use the Bluetooth Event Trigger API for this. The example Bluetooth: Event Trigger is setting up triggers on Connection Events. If you change the function `setup_connection_event_trigger()` to something like the following code snippet, you should be able to trigger at Advertising Events instead.

static int setup_advertisement_event_trigger(struct bt_le_ext_adv *adv_set, bool enable)
{
	int err;
	sdc_hci_cmd_vs_set_event_start_task_t cmd_params = {};
	uint8_t adv_handle;

	err = bt_hci_get_adv_handle(adv_set, &adv_handle);
	if (err) {
		printk("Failed obtaining handle: %s (%d)\n", strerror(-err), err);
		return err;
	}

	cmd_params.handle_type = SDC_HCI_VS_SET_EVENT_START_TASK_HANDLE_TYPE_ADV;
	cmd_params.handle = adv_handle;

	if (enable) {
		cmd_params.task_address = nrf_egu_task_address_get(NRF_EGU, NRF_EGU_TASK_TRIGGER0);

		IRQ_DIRECT_CONNECT(DT_IRQN(EGU_NODE), 5, egu_handler, 0);
		nrf_egu_int_enable(NRF_EGU, NRF_EGU_INT_TRIGGERED0);
		NVIC_EnableIRQ(DT_IRQN(EGU_NODE));
	} else {
		cmd_params.task_address = 0;
		nrf_egu_int_disable(NRF_EGU, NRF_EGU_INT_TRIGGERED0);
		NVIC_DisableIRQ(DT_IRQN(EGU_NODE));
	}

	err = hci_vs_sdc_set_event_start_task(&cmd_params);
	if (err) {
		printk("Error for command hci_vs_sdc_set_event_start_task(): %s (%d)\n",
		       strerror(-err), err);
		return err;
	}

	printk("Successfully configured event trigger\n");

	return 0;
}

Call that function after you have created your Extended Adverisement Set. Create a worker callback function that updates your Advertisement Data by using the function `bt_le_ext_adv_set_data()` every time the event is triggered.

Note that Extended Advertisements are sent out with a small random delay added to your chosen interval (1 second). If that is a problem you may want to have a look at Periodic Advertising (Bluetooth 5.0). Also Periodic Advertising with Responses (PAwR, Bluetooth 5.4) is a very powerful feature for connecting multiple sensors to one access point.