What new features were released in ncs1.7.0 about advertising?

RE: What new features were released in ncs1.7.0 about advertising?

Simonr — Fri, 15 Oct 2021 13:34:39 GMT

By default the receiver is only set up to support reading so I think there are a few more tweaks necessary to make it be able to synchronize with multiple ones. If the 3 advertisers are close together it might also be that they interfere with one another which cause the incorrect IQ data.

Best regards,

Simon

RE: What new features were released in ncs1.7.0 about advertising?

Deang — Thu, 14 Oct 2021 07:26:34 GMT

Hi Simonr,

Thank you so much.

I understood it. The reason is my smart phone can't scan periodic advertising data, it led me to think bt_le_per_adv_set_data can't work. So, I run direction_finding_connectionless_rx sample it can scan periodic advertising data.

But it only create synchronization with a slave even if setting CONFIG_BT_PER_ADV_SYNC_MAX=3 in the direction_finding_connectionless_rx sample. So I did some changes in the sample, here is the source code,devzone.nordicsemi.com/.../37650.main.c

It can establish synchronization with 3 slaves at the same time, but can only receive IQ data from 1 tag, and sometimes the IQ-data was wrong, the following is running log

RE: What new features were released in ncs1.7.0 about advertising?

Simonr — Wed, 13 Oct 2021 07:15:21 GMT

2. The advertising sets in the direction finding example uses the following struct to set up the advertising sets. What kind of issues do you have trying to set up the bt_le_per_adv_set_data?

static struct bt_le_ext_adv *adv_set;

const static struct bt_le_adv_param param =
		BT_LE_ADV_PARAM_INIT(BT_LE_ADV_OPT_EXT_ADV |
				     BT_LE_ADV_OPT_USE_NAME,
				     BT_GAP_ADV_FAST_INT_MIN_2,
				     BT_GAP_ADV_FAST_INT_MAX_2,
				     NULL);

static struct bt_le_ext_adv_start_param ext_adv_start_param = {
	.timeout = 0,
	.num_events = 0,
};

const static struct bt_le_per_adv_param per_adv_param = {
	.interval_min = BT_GAP_ADV_SLOW_INT_MIN,
	.interval_max = BT_GAP_ADV_SLOW_INT_MAX,
	.options = BT_LE_ADV_OPT_USE_TX_POWER,
};

5. The Bluetooth SIG specification only supports up to 8 bit resolution of the I and Q samples. which is why these are set to 8 bit in our example project. The nRF52833 supports a resolution of up to 12 bits, but we've not added support for a proprietary extension yet.

Best regards,

Simon

RE: What new features were released in ncs1.7.0 about advertising?

Deang — Tue, 12 Oct 2021 07:43:16 GMT

Hi Simonr,

Question-2: I run nrf/samples/bluetooth/sample direction_finding_connectionless_tx, and it use zephyr controller, but it can't set advertising data by calling bt_le_per_adv_set_data. And it's same to run sample zephyr/samples/bluetooth/periodic_adv. Can you help me to confirm the api wether it worked?

Question-5: I'm sorry that I misunderstood the documentation, But it's 8-bits signed in file "zephyr/include/bluetooth/hci.h",

RE: What new features were released in ncs1.7.0 about advertising?

Simonr — Tue, 12 Oct 2021 06:43:08 GMT

1. The same goes for nRFConnect SDK (NCS) v1.7.0 as well. One advertisement can be up t 251 bytes. You can also used chained advertising to reach up to 255 bytes of advertising. We will support larger chained advertising in the future.

2. The bt_le_per_adv_set_data seems to be part of the Zephyr stack, so it should be usable if you're using the Zephyr controller.

3. Yes, the Direction Finding sample projects in NCS are BLE compatible and can be used in products, but you'll likely want to make some changes to the sample projects to fit your product as good as possible.

4. There does not seem to be a limit in the Bluetooth specification to the max number of simultaneous periodic advertising syncs. From what I can tell the restriction may be due to the use of a uint8_t for indices and memory buffer counts. If more than 64 instances are buildable and functional, you are free to increase this to what you'd like.

5. From what I can see both I and Q samples are 12 bits signed. Where do you see that the I samples are 16-bits unsigned in the documentation and 8-bits in NCS?

Best regards,

Simon

RE: What new features were released in ncs1.7.0 about advertising?

Deang — Tue, 12 Oct 2021 03:02:33 GMT

Add the question:

4. Why is CONFIG_BT_PER_ADV_SYNC_MAX maximum is 64? What does limit it? Core spec, timing sequence, memory or others?

5. For format of IQ sampling, I is 16-bits unsigned and Q is 12-bits signed in nRF52833 production specification, but both I and Q are 8-bit signed in ncs. Why are they different?