Enable event lenght extension on sdk 1.7.0

RE: Enable event lenght extension on sdk 1.7.0

Martijn Jonkers — Tue, 04 Jan 2022 09:36:36 GMT

could it be the 'dynamic event length' is already enabled by default in the throughput example?

RE: Enable event lenght extension on sdk 1.7.0

sotillo2409 — Tue, 04 Jan 2022 09:32:08 GMT

Hi,

I see a similar implementation on another example, could you check that this is correct?

static int EvtLen(void)
{       
        int err;
	struct net_buf *buf;
	sdc_hci_cmd_vs_conn_event_extend_t *evt_enable;

	buf = bt_hci_cmd_create(SDC_HCI_OPCODE_CMD_VS_CONN_EVENT_EXTEND,
				sizeof(*evt_enable));
	if (!buf) {
		printk("Could not allocate LLPM command buffer\n");
		return -ENOMEM;
	}
        evt_enable = net_buf_add(buf, sizeof(*evt_enable));
	evt_enable->enable = 2;

	err = bt_hci_cmd_send_sync(SDC_HCI_OPCODE_CMD_VS_CONN_EVENT_EXTEND, buf, NULL);
	if (err) {
		printk("Error enabling EVENT %d\n", err);
		return err;
	}

	printk("EVENT mode enabled\n");
	return 0;
}

RE: Enable event lenght extension on sdk 1.7.0

sotillo2409 — Tue, 04 Jan 2022 08:37:38 GMT

Hi,

that was an usefull information, i appreciate it. But I am not able to implement a way to enable/disable extended connection events.

        sdc_hci_cmd_vs_conn_event_extend_t x={0};

        erri=sdc_hci_cmd_vs_conn_event_extend(&x);
        
        if(erri)printk("FALLO CON EVT LEN");
        else printk("OK EVT LEN");

I am trying this, and the function is returning 0 always, inclusive when i pass a 2 on the argument.

Could you tell me what is the propper way to

[quote userid="72692" url="~/f/nordic-q-a/83088/enable-event-lenght-extension-on-sdk-1-7-0/345707#345707"] send the HCI command SDC_HCI_OPCODE_CMD_VS_CONN_EVENT_EXTEND from the BLE host to the BLE[/quote]

I am trying to follow this ticket:

[quote userid="72692" url="~/f/nordic-q-a/83088/enable-event-lenght-extension-on-sdk-1-7-0/345707#345707"]This ticket[/quote]

But on the actual ncs 1.7.0 i am not able to reproduce it. I am working with nrf52840.

Thank you for the help and regards.

RE: Enable event lenght extension on sdk 1.7.0

Simon — Mon, 03 Jan 2022 14:44:11 GMT

Sorry for being too quick and not answering your question. Let's try again

Regarding the event length, see the comment in softdevice_controller/include/sdc_hci_vs.h:

* When Extended Connection Events are disabled, the maximum connection event length is set by @ref
* sdc_hci_cmd_vs_event_length_set().
* When Extended Connection Events are enabled, the controller will extend the connection event as
* much as possible, if:
* - Either of the peers has more data to send.
* See also: Core v5.1, Vol 6, Part B, Section 4.5.6
* - There are no conflicts with other concurrent links.
*
* A connection event can not be extended beyond the connection interval.

So, if you enable extended connection events (dynamic eventh length), the maximum event length is set by the connection interval. To set the connection interval check out the example nrf/samples/bluetooth/throughput and this case: https://devzone.nordicsemi.com/f/nordic-q-a/69473/ncs-connection-interval-changing-to-config_bt_peripheral_pref_max_int-after-5s

If you disable extended connection events (constant eventh length), the maximum event length is set by the event length, which can be set through the config CONFIG_SDC_MAX_CONN_EVENT_LEN_DEFAULT

To enable/disable extended connection events, send the HCI command SDC_HCI_OPCODE_CMD_VS_CONN_EVENT_EXTEND from the BLE host to the BLE controller, which will trigger the function sdc_hci_cmd_vs_conn_event_extend()

This ticket explains event length/event length extension in great details

Best regards,

Simon

RE: Enable event lenght extension on sdk 1.7.0

sotillo2409 — Mon, 03 Jan 2022 07:36:04 GMT

On another words, i need to know how to modify NRF_SDH_BLE_GAP_EVENT_LENGTH

on the actual ncs, because of i can't find any k_config for this.

Thank you.

RE: Enable event lenght extension on sdk 1.7.0

sotillo2409 — Mon, 03 Jan 2022 06:54:09 GMT

Sorry for the misunderstanding, i am using nRF Connect for Desktop v3.9.1, wth NCS 1.7.0.

[quote userid="72692" url="~/f/nordic-q-a/83088/enable-event-lenght-extension-on-sdk-1-7-0/345276#345276"]Regarding data length extension, check out the example nrf/samples/bluetooth/throughput, which uses a data length of 251[/quote]

I am not speaking about DATA length extension, I want to know a way to have control on the EVENT length extension that softdevice uses to allocae every peripheral on it schedule. On another words, if is there some method to have control on Event length extension, to fix a constant time to every peripheral connection.

On addition i want to know where and how enable the event length extension.

The aim of this is have total control on number of packets per every ble connection interval.

regards.

RE: Enable event lenght extension on sdk 1.7.0

Simon — Tue, 28 Dec 2021 15:19:43 GMT

Modified jan 4 2022: Applied strikethrough since I didn't address the question

Be aware that we offer two SDKs, the nRF5 SDK and the nRF Connect SDK (NCS). In the tickets you referred to, the nRF5 SDK was used, and those won't help you since you're using NCS.

Read about the differences here:

https://devzone.nordicsemi.com/nordic/nordic-blog/b/blog/posts/nrf-connect-sdk-and-nrf5-sdk-statement

Regarding data length extension, check out the example nrf/samples/bluetooth/throughput, which uses a data length of 251 bytes by default. Read more about it in the documentation http://developer.nordicsemi.com/nRF_Connect_SDK/doc/1.8.0/nrf/samples/bluetooth/throughput/README.html#overview

Best regards,

Simon