samples: bluetooth: Add Channel Sounding Reflector with RRSP sample

This sample can be used to set up a Channel Sounding Reflector with
the GATT Ranging Responder service.
A Channel Sounding Initiator with Ranging Requestor can connect to this
sample to receive CS Ranging Data and perform distance estimation.

Signed-off-by: Aleksandar Stanoev <aleksandar.stanoev@nordicsemi.no>

CODEOWNERS

@@ -413,6 +413,7 @@
 /samples/bluetooth/central_nfc_pairing/   @nrfconnect/ncs-si-muffin
 /samples/bluetooth/central_smp_client/    @nrfconnect/ncs-si-muffin
 /samples/bluetooth/central_uart/          @nrfconnect/ncs-si-muffin
+/samples/bluetooth/channel_sounding_ras_reflector/ @nrfconnect/ncs-dragoon
 /samples/bluetooth/conn_time_sync/        @nrfconnect/ncs-dragoon
 /samples/bluetooth/direction_finding_central/ @nrfconnect/ncs-dragoon
 /samples/bluetooth/direction_finding_connectionless_rx/ @nrfconnect/ncs-dragoon

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

@@ -235,7 +235,9 @@ Amazon Sidewalk samples
 Bluetooth samples
 -----------------
 
-|no_changes_yet_note|
+* Added:
+
+  * The :ref:`channel_sounding_ras_reflector` sample demonstrating how to implement a Channel Sounding Reflector that exposes the Ranging Responder GATT Service.
 
 Bluetooth Fast Pair samples
 ---------------------------

samples/bluetooth/channel_sounding_ras_reflector/CMakeLists.txt

@@ -0,0 +1,15 @@
+#
+# Copyright (c) 2024 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+cmake_minimum_required(VERSION 3.20.0)
+
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(channel_sounding_ras_reflector)
+
+# NORDIC SDK APP START
+target_sources(app PRIVATE
+  src/main.c
+)
+# NORDIC SDK APP END

samples/bluetooth/channel_sounding_ras_reflector/README.rst

@@ -0,0 +1,78 @@
+.. _channel_sounding_ras_reflector:
+
+Bluetooth: Channel Sounding Reflector with Ranging Responder
+############################################################
+
+.. contents::
+   :local:
+   :depth: 2
+
+This sample demonstrates how to use the ranging service to provide ranging data to a client.
+
+Requirements
+************
+
+The sample supports the following development kits:
+
+.. table-from-sample-yaml::
+
+The sample also requires a device running a Channel Sounding Initiator with Ranging Requestor to connect to.
+
+Overview
+********
+
+The sample demonstrates a basic Bluetooth® Low Energy Peripheral role functionality that exposes the GATT Ranging Responder Service and configures the Channel Sounding reflector role.
+When Channel Sounding Ranging Data is generated by the controller, it will be automatically stored by the Ranging Service, and can be queried at any time by the Ranging Requestor.
+The Channel Sounding Ranging Data can then be used by the peer device to perform distance estimation.
+
+User interface
+**************
+
+The sample does not require user input and will advertise using the GATT Ranging Service UUID.
+The first LED on the development kit will be lit when a connection has been established.
+
+Building and running
+********************
+.. |sample path| replace:: :file:`samples/bluetooth/channel_sounding_ras_reflector`
+
+.. include:: /includes/build_and_run.txt
+
+Testing
+=======
+
+After programming the sample to your development kit, you can test it by connecting to another development kit with a Channel Sounding Initiator role with Ranging Requestor.
+
+1. |connect_terminal_specific|
+#. Reset the kit.
+#. Program the other kit with the Channel Sounding Initiator with Ranging Requestor sample.
+#. Wait until the advertiser is detected by the Central.
+   In the terminal window, check for information similar to the following::
+
+      Connected to xx.xx.xx.xx.xx.xx (random) (err 0x00)
+      CS capability exchange completed.
+      CS config creation complete. ID: 0
+      CS security enabled.
+      CS procedures enabled.
+
+Dependencies
+************
+
+This sample uses the following |NCS| libraries:
+
+* :ref:`dk_buttons_and_leds_readme`
+* :file:`include/bluetooth/services/ras.h`
+
+This sample uses the following Zephyr libraries:
+
+* :file:`include/sys/printk.h`
+* :file:`include/zephyr/types.h`
+* :ref:`zephyr:kernel_api`:
+
+  * :file:`include/kernel.h`
+
+* :ref:`zephyr:bluetooth_api`:
+
+* :file:`include/bluetooth/bluetooth.h`
+* :file:`include/bluetooth/conn.h`
+* :file:`include/bluetooth/uuid.h`
+* :file:`include/bluetooth/cs.h`

samples/bluetooth/channel_sounding_ras_reflector/prj.conf

@@ -0,0 +1,27 @@
+#
+# Copyright (c) 2024 Nordic Semiconductor ASA
+#
+# SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+#
+
+CONFIG_NCS_SAMPLES_DEFAULTS=y
+CONFIG_DK_LIBRARY=y
+
+CONFIG_BT=y
+CONFIG_BT_PERIPHERAL=y
+CONFIG_BT_SMP=y
+CONFIG_BT_DEVICE_NAME="Nordic CS Reflector"
+CONFIG_BT_MAX_CONN=1
+CONFIG_BT_GAP_AUTO_UPDATE_CONN_PARAMS=n
+CONFIG_BT_BONDABLE=n
+
+# The Ranging Profile recommends a MTU of at least 247 octets.
+CONFIG_BT_L2CAP_TX_MTU=498
+CONFIG_BT_BUF_ACL_TX_SIZE=502
+CONFIG_BT_BUF_ACL_RX_SIZE=502
+CONFIG_BT_CTLR_DATA_LENGTH_MAX=251
+CONFIG_BT_CTLR_PHY_2M=y
+
+CONFIG_BT_CHANNEL_SOUNDING=y
+CONFIG_BT_RAS=y
+CONFIG_BT_RAS_RRSP=y

samples/bluetooth/channel_sounding_ras_reflector/sample.yaml

@@ -0,0 +1,12 @@
+sample:
+  description: Bluetooth Low Energy Channel Sounding Reflector with Ranging Service Responder
+  name: Bluetooth LE Channel Sounding Reflector with RRSP
+tests:
+  sample.bluetooth.channel_sounding_ras_reflector:
+    sysbuild: true
+    build_only: true
+    integration_platforms:
+      - nrf54l15dk/nrf54l15/cpuapp
+    platform_allow:
+      - nrf54l15dk/nrf54l15/cpuapp
+    tags: bluetooth ci_build sysbuild

samples/bluetooth/channel_sounding_ras_reflector/src/main.c

@@ -0,0 +1,139 @@
+/*
+ * Copyright (c) 2024 Nordic Semiconductor ASA
+ *
+ * SPDX-License-Identifier: LicenseRef-Nordic-5-Clause
+ */
+
+/** @file
+ *  @brief Channel Sounding Reflector with Ranging Responder sample
+ */
+
+#include <zephyr/sys/printk.h>
+#include <zephyr/types.h>
+#include <zephyr/kernel.h>
+#include <zephyr/bluetooth/bluetooth.h>
+#include <zephyr/bluetooth/conn.h>
+#include <zephyr/bluetooth/uuid.h>
+#include <zephyr/bluetooth/cs.h>
+#include <bluetooth/services/ras.h>
+
+#include <dk_buttons_and_leds.h>
+
+#define CON_STATUS_LED DK_LED1
+
+static K_SEM_DEFINE(sem_connected, 0, 1);
+
+static struct bt_conn *connection;
+
+static const struct bt_data ad[] = {
+	BT_DATA_BYTES(BT_DATA_FLAGS, (BT_LE_AD_GENERAL | BT_LE_AD_NO_BREDR)),
+	BT_DATA_BYTES(BT_DATA_UUID16_ALL, BT_UUID_16_ENCODE(BT_UUID_RANGING_SERVICE_VAL)),
+	BT_DATA(BT_DATA_NAME_COMPLETE, CONFIG_BT_DEVICE_NAME, sizeof(CONFIG_BT_DEVICE_NAME) - 1),
+};
+
+static void connected_cb(struct bt_conn *conn, uint8_t err)
+{
+	char addr[BT_ADDR_LE_STR_LEN];
+
+	(void)bt_addr_le_to_str(bt_conn_get_dst(conn), addr, sizeof(addr));
+	printk("Connected to %s (err 0x%02X)\n", addr, err);
+
+	if (err) {
+		bt_conn_unref(conn);
+		connection = NULL;
+	}
+
+	connection = bt_conn_ref(conn);
+
+	k_sem_give(&sem_connected);
+
+	dk_set_led_on(CON_STATUS_LED);
+}
+
+static void disconnected_cb(struct bt_conn *conn, uint8_t reason)
+{
+	printk("Disconnected (reason 0x%02X)\n", reason);
+
+	bt_conn_unref(conn);
+	connection = NULL;
+
+	dk_set_led_off(CON_STATUS_LED);
+}
+
+static void remote_capabilities_cb(struct bt_conn *conn, struct bt_conn_le_cs_capabilities *params)
+{
+	ARG_UNUSED(conn);
+	ARG_UNUSED(params);
+	printk("CS capability exchange completed.\n");
+}
+
+static void config_created_cb(struct bt_conn *conn, struct bt_conn_le_cs_config *config)
+{
+	ARG_UNUSED(conn);
+	printk("CS config creation complete. ID: %d\n", config->id);
+}
+
+static void security_enabled_cb(struct bt_conn *conn)
+{
+	ARG_UNUSED(conn);
+	printk("CS security enabled.\n");
+}
+
+static void procedure_enabled_cb(struct bt_conn *conn,
+				 struct bt_conn_le_cs_procedure_enable_complete *params)
+{
+	ARG_UNUSED(conn);
+	if (params->state == 1) {
+		printk("CS procedures enabled.\n");
+	} else {
+		printk("CS procedures disabled.\n");
+	}
+}
+
+BT_CONN_CB_DEFINE(conn_cb) = {
+	.connected = connected_cb,
+	.disconnected = disconnected_cb,
+	.le_cs_remote_capabilities_available = remote_capabilities_cb,
+	.le_cs_config_created = config_created_cb,
+	.le_cs_security_enabled = security_enabled_cb,
+	.le_cs_procedure_enabled = procedure_enabled_cb,
+};
+
+int main(void)
+{
+	int err;
+
+	printk("Starting Channel Sounding Reflector Sample\n");
+
+	dk_leds_init();
+
+	err = bt_enable(NULL);
+	if (err) {
+		printk("Bluetooth init failed (err %d)\n", err);
+		return 0;
+	}
+
+	err = bt_le_adv_start(BT_LE_ADV_CONN, ad, ARRAY_SIZE(ad), NULL, 0);
+	if (err) {
+		printk("Advertising failed to start (err %d)\n", err);
+		return 0;
+	}
+
+	while (true) {
+		k_sem_take(&sem_connected, K_FOREVER);
+
+		const struct bt_le_cs_set_default_settings_param default_settings = {
+			.enable_initiator_role = false,
+			.enable_reflector_role = true,
+			.cs_sync_antenna_selection = BT_LE_CS_ANTENNA_SELECTION_OPT_REPETITIVE,
+			.max_tx_power = BT_HCI_OP_LE_CS_MAX_MAX_TX_POWER,
+		};
+
+		err = bt_le_cs_set_default_settings(connection, &default_settings);
+		if (err) {
+			printk("Failed to configure default CS settings (err %d)\n", err);
+		}
+	}
+
+	return 0;
+}