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samples: Bluetooth: add concurrent scanner and initiator sample
Add sample application that demonstrates faster connection establishment using CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL. Signed-off-by: Henrik Lander <[email protected]>
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‎CODEOWNERS‎

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/samples/bluetooth/radio_coex_1wire/ @nrfconnect/ncs-dragoon
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/samples/bluetooth/radio_notification_cb/ @nrfconnect/ncs-dragoon
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/samples/bluetooth/rpc_host/ @nrfconnect/ncs-si-muffin
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/samples/bluetooth/scanning_while_connecting/ @nrfconnect/ncs-dragoon
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/samples/bluetooth/shell_bt_nus/ @nrfconnect/ncs-si-muffin
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/samples/bluetooth/subrating/ @nrfconnect/ncs-dragoon
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/samples/bluetooth/throughput/ @nrfconnect/ncs-si-muffin

‎doc/nrf/releases_and_maturity/releases/release-notes-changelog.rst‎

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* Added support for the :ref:`zephyr:nrf54h20dk_nrf54h20` board target.
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* The :ref:`bt_scanning_while_connecting` sample demonstrating how to establish multiple connections faster using the :kconfig:option:`CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL` Kconfig option.
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* Updated:
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* Configurations of the following Bluetooth samples to make the :ref:`Zephyr Memory Storage (ZMS) <zephyr:zms_api>` the default settings backend for all board targets that use the MRAM technology:

‎samples/bluetooth/scanning_while_connecting/CMakeLists.txt‎

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#
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# Copyright (c) 2024 Nordic Semiconductor
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#
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# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
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#
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cmake_minimum_required(VERSION 3.20.0)
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find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
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project(scanning_while_connecting)
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target_sources(app PRIVATE src/main.c)

‎samples/bluetooth/scanning_while_connecting/Kconfig.sysbuild‎

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#
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# Copyright (c) 2024 Nordic Semiconductor
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#
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# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
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#
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source "${ZEPHYR_BASE}/share/sysbuild/Kconfig"
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config NRF_DEFAULT_IPC_RADIO
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default y

‎samples/bluetooth/scanning_while_connecting/README.rst‎

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.. _bt_scanning_while_connecting:
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Bluetooth: Scanning while connecting
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####################################
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.. contents::
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:local:
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:depth: 2
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The sample demonstrates how to reduce the time to establish connections to many devices, typically done when provisioning devices to a network.
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The total connection establishment time is reduced by scanning while connecting and by using the filter accept list.
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Requirements
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************
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The sample supports the following development kits:
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.. table-from-sample-yaml::
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The sample also requires at least one other development kit.
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Out of the box, this sample can be used together with the :ref:`bt_peripheral_with_multiple_identities`.
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This sample filters out devices with a different name than a device running the :ref:`bt_peripheral_with_multiple_identities` sample.
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The :ref:`bt_peripheral_with_multiple_identities` sample acts as multiple peripheral devices.
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Overview
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********
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You can use this sample as a starting point to implement an application designed to provision a network of Bluetooth peripherals.
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The approaches demonstrated in this sample will reduce the total time to connect to many devices.
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A typical use-case is a gateway in a network of devices using Periodic Advertising with Responses.
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To illustrate how connection establishment speed can be improved, it measures the time needed to connect to 16 devices with three different modes:
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* sequential scanning and connection establishment
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* concurrent scanning while connecting
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* concurrent scanning while connecting with the filter accept list.
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Sequential scanning and connection establishment
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================================================
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This is the slowest and simplest approach.
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Sequential scanning and connection establishment are recommended when the application only needs to connect a handful of devices.
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After a device is discovered, the application stops scanning and attempts to connect to the device.
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Once the connection is established, the application starts the scanner again to discover other connectable devices.
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The following message sequence chart illustrates the sequence of events.
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.. msc::
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hscale = "1.3";
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App, Stack, Peers;
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App=>Stack [label="scan_start()"];
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Peers=>Stack [label="ADV_IND(A)"];
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Stack=>App [label="scan_recv(A)"];
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App=>Stack [label="scan_stop()"];
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App=>Stack [label="bt_conn_le_create(A)"];
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Peers=>Stack [label="ADV_IND(A)"];
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Stack=>Peers [label="CONNECT_IND(A)"];
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Stack=>App [label="connected_cb(A)"];
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App=>Stack [label="scan_start()"];
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Peers=>Stack [label="ADV_IND(B)"];
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Stack=>App [label="scan_recv(B)"];
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App=>Stack [label="scan_stop()"];
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App=>Stack [label="bt_conn_le_create(B)"];
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Peers=>Stack [label="ADV_IND(B)"];
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Stack=>Peers [label="CONNECT_IND(B)"];
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Stack=>App [label="connected_cb(B)"];
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Concurrent scanning while connecting
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====================================
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This mode requires the application to enable the :kconfig:option:`CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL` Kconfig option.
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In this mode, the scanner is not stopped when the application creates connections.
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During a connection establishment procedure to a device, the application caches other devices it also wants to connect to.
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Once the connection establishment procedure is complete, it can immediately initiate a new connection establishment procedure to the cached device.
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When connecting to a cached device, the connection establishment procedure takes one less advertising interval compared to the sequential scanning and connection establishment mode.
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.. msc::
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hscale = "1.3";
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App, Stack, Peers;
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App=>Stack [label="scan_start()"];
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Peers=>Stack [label="ADV_IND(A)"];
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Stack=>App [label="scan_recv(A)"];
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App=>Stack [label="bt_conn_le_create(A)"];
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Peers=>Stack [label="ADV_IND(B)"];
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App rbox App [label="Cache address B"];
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Peers=>Stack [label="ADV_IND(A)"];
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Stack=>Peers [label="CONNECT_IND(A)"];
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Stack=>App [label="connected_cb(A)"];
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App=>Stack [label="bt_conn_le_create(B)"];
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Peers=>Stack [label="ADV_IND(B)"];
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Stack=>Peers [label="CONNECT_IND(B)"];
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Stack=>App [label="connected_cb(B)"];
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Concurrent scanning while connecting with the filter accept list
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================================================================
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This mode requires the application to enable the :kconfig:option:`CONFIG_BT_FILTER_ACCEPT_LIST` Kconfig option in addition to :kconfig:option:`CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL`.
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When the application starts the connection establishment procedure with the filter accept list, it can connect to any of the previously cached devices.
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This reduces the total connection setup time even more, because connection establishment is not relying on the on-air presence of only one of the cached devices.
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.. msc::
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hscale = "1.3";
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App, Stack, Peers;
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App=>Stack [label="scan_start()"];
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Peers=>Stack [label="ADV_IND(A)"];
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Stack=>App [label="scan_recv(A)"];
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App=>Stack [label="bt_conn_le_create(A)"];
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Peers=>Stack [label="ADV_IND(B)"];
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Peers=>Stack [label="ADV_IND(C)"];
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Peers=>Stack [label="ADV_IND(D)"];
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App rbox App [label="Cache addresses B, C, D"];
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Peers=>Stack [label="ADV_IND(A)"];
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Stack=>Peers [label="CONNECT_IND(A)"];
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Stack=>App [label="connected_cb(A)"];
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App rbox App [label="Set filter accept list to\nB, C, D"];
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App=>Stack [label="bt_conn_le_create_auto()"];
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Stack rbox Stack [label="The stack will connect to the first present ADV_IND of\nthe peers B,C,D"];
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Peers=>Stack [label="ADV_IND(C)"];
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Stack=>Peers [label="CONNECT_IND(C)"];
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Stack=>App [label="connected_cb(C)"];
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.. note::
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This sample application assumes it will never have to cache more devices than the maximum number of addresses that can be stored in the filter accept list.
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For applications that cannot adhere to this simplification, the function :c:func:`cache_peer_address` can be changed to not store more than defined by the :kconfig:option:`CONFIG_BT_CTLR_FAL_SIZE` Kconfig option.
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Another simplification done in the sample application is storing duplicate devices in the filter accept list.
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Configuration
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*************
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|config|
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Building and running
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********************
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.. |sample path| replace:: :file:`samples/bluetooth/scanning_while_connecting`
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.. include:: /includes/build_and_run.txt
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Testing
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=======
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|test_sample|
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1. |connect_kit|
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#. |connect_terminal|
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#. Observe that the sample connects and prints out how much time it takes to connect to all peripherals.
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Sample output
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=============
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The result should look similar to the following output::
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*** Booting nRF Connect SDK v2.8.99-1c63490f0539 ***
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*** Using Zephyr OS v3.7.99-b9bc0846b926 ***
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I: SoftDevice Controller build revision:
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I: 49 40 e2 c0 6b e5 0d b3 |[email protected]...
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I: ba a6 48 5e 49 a6 95 3d |..H^I..=
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I: 65 35 b6 7c |e5.|
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I: HW Platform: Nordic Semiconductor (0x0002)
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I: HW Variant: nRF54Lx (0x0005)
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I: Firmware: Standard Bluetooth controller (0x00) Version 73.57920 Build 233139136
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I: Identity: F6:BF:24:7D:46:5D (random)
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I: HCI: version 6.0 (0x0e) revision 0x3030, manufacturer 0x0059
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I: LMP: version 6.0 (0x0e) subver 0x3030
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I: Bluetooth initialized
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I: SEQUENTIAL_SCAN_AND_CONNECT:
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I: starting sample benchmark
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I: Connected to FF:AB:68:0C:34:FD (random), number of connections 1
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I: Connected to E2:12:BF:D3:FB:D5 (random), number of connections 2
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I: Connected to EE:37:AA:62:A2:FB (random), number of connections 3
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I: Connected to C7:9B:42:1B:48:F8 (random), number of connections 4
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I: Connected to F0:27:5B:37:0F:4B (random), number of connections 5
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I: Connected to C8:BA:1D:6F:95:2B (random), number of connections 6
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I: Connected to DF:02:31:C3:0B:C2 (random), number of connections 7
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I: Connected to C7:E1:60:7A:F1:E0 (random), number of connections 8
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I: Connected to CA:89:50:33:AB:31 (random), number of connections 9
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I: Connected to E9:47:6B:FA:2F:DE (random), number of connections 10
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I: Connected to EF:92:DC:88:3B:B3 (random), number of connections 11
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I: Connected to F4:9C:8C:24:F9:44 (random), number of connections 12
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I: Connected to DD:84:44:64:5D:FB (random), number of connections 13
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I: Connected to FB:92:1D:8E:8C:D8 (random), number of connections 14
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I: Connected to D9:E5:51:E0:5E:24 (random), number of connections 15
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I: Connected to CF:2F:99:89:A3:4D (random), number of connections 16
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I: 12 seconds to create 16 connections
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I: Disconnecting connections...
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I: ---------------------------------------------------------------------
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I: ---------------------------------------------------------------------
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I: CONCURRENT_SCAN_AND_CONNECT:
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I: starting sample benchmark
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I: Connected to F0:27:5B:37:0F:4B (random), number of connections 1
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I: Connected to EE:37:AA:62:A2:FB (random), number of connections 2
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I: Connected to D1:3D:B1:AA:84:27 (random), number of connections 3
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I: Connected to CA:89:50:33:AB:31 (random), number of connections 4
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I: Connected to C0:38:F8:47:10:17 (random), number of connections 5
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I: Connected to E9:47:6B:FA:2F:DE (random), number of connections 6
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I: Connected to D9:E5:51:E0:5E:24 (random), number of connections 7
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I: Connected to FB:92:1D:8E:8C:D8 (random), number of connections 8
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I: Connected to C7:E1:60:7A:F1:E0 (random), number of connections 9
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I: Connected to E2:6D:21:28:C7:DB (random), number of connections 10
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I: Connected to DF:02:31:C3:0B:C2 (random), number of connections 11
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I: Connected to F0:F2:2A:C1:F7:72 (random), number of connections 12
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I: Connected to DD:84:44:64:5D:FB (random), number of connections 13
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I: Connected to F4:9C:8C:24:F9:44 (random), number of connections 14
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I: Connected to EF:92:DC:88:3B:B3 (random), number of connections 15
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I: Connected to C8:BA:1D:6F:95:2B (random), number of connections 16
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I: 9 seconds to create 16 connections
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I: Disconnecting connections...
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I: ---------------------------------------------------------------------
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I: ---------------------------------------------------------------------
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I: CONCURRENT_SCAN_AND_CONNECT_FILTER_ACCEPT_LIST:
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I: starting sample benchmark
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I: Connected to DD:84:44:64:5D:FB (random), number of connections 1
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I: Connected to C7:E1:60:7A:F1:E0 (random), number of connections 2
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I: Connected to C7:9B:42:1B:48:F8 (random), number of connections 3
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I: Connected to E9:47:6B:FA:2F:DE (random), number of connections 4
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I: Connected to E2:12:BF:D3:FB:D5 (random), number of connections 5
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I: Connected to FB:92:1D:8E:8C:D8 (random), number of connections 6
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I: Connected to F0:F2:2A:C1:F7:72 (random), number of connections 7
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I: Connected to CA:89:50:33:AB:31 (random), number of connections 8
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I: Connected to F4:9C:8C:24:F9:44 (random), number of connections 9
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I: Connected to E2:6D:21:28:C7:DB (random), number of connections 10
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I: Connected to FF:AB:68:0C:34:FD (random), number of connections 11
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I: Connected to EE:37:AA:62:A2:FB (random), number of connections 12
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I: Connected to D1:3D:B1:AA:84:27 (random), number of connections 13
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I: Connected to CF:2F:99:89:A3:4D (random), number of connections 14
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I: Connected to EF:92:DC:88:3B:B3 (random), number of connections 15
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I: Connected to D9:E5:51:E0:5E:24 (random), number of connections 16
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I: 4 seconds to create 16 connections
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I: Disconnecting connections...
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I: ---------------------------------------------------------------------
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I: ---------------------------------------------------------------------

‎samples/bluetooth/scanning_while_connecting/prj.conf‎

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#
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# Copyright (c) 2024 Nordic Semiconductor
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#
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# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
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#
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CONFIG_NCS_SAMPLES_DEFAULTS=y
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CONFIG_BT=y
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CONFIG_BT_CENTRAL=y
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CONFIG_BT_FILTER_ACCEPT_LIST=y
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CONFIG_BT_SCAN_AND_INITIATE_IN_PARALLEL=y
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CONFIG_BT_CTLR_SDC_ALLOW_PARALLEL_SCANNING_AND_INITIATING=y
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# A ring buffer is used as a device address cache
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CONFIG_RING_BUFFER=y
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CONFIG_BT_CTLR_FAL_SIZE=255
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CONFIG_LOG=y
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CONFIG_BT_MAX_CONN=16
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CONFIG_BT_BUF_ACL_RX_COUNT=17

‎samples/bluetooth/scanning_while_connecting/sample.yaml‎

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sample:
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description: Bluetooth Low Energy fast connection establishment sample
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name: Bluetooth LE central scanning while connecting
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tests:
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sample.bluetooth.scanning_while_connecting:
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sysbuild: true
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build_only: true
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integration_platforms:
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- nrf52840dk/nrf52840
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- nrf5340dk/nrf5340/cpuapp
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- nrf54l15dk/nrf54l15/cpuapp
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- nrf54l15dk/nrf54l10/cpuapp
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- nrf54l15dk/nrf54l05/cpuapp
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platform_allow:
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- nrf52840dk/nrf52840
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- nrf5340dk/nrf5340/cpuapp
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- nrf54l15dk/nrf54l15/cpuapp
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- nrf54l15dk/nrf54l10/cpuapp
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- nrf54l15dk/nrf54l05/cpuapp
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tags: bluetooth ci_build sysbuild

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