bluetooth: samples: Add sample showing basic channel sounding features

include/zephyr/bluetooth/cs.h

@@ -540,6 +540,35 @@ struct bt_le_cs_subevent_step {
 	const uint8_t *data;
 };
 
+/** Sign-extended IQ sample extracted from step data. */
+struct bt_le_cs_iq_sample {
+	int16_t i;
+	int16_t q;
+};
+
+/** @brief Extract IQ sample from HCI-formatted PCT.
+ *
+ * Convenience function for processing 24-bit phase correction terms found
+ * in CS step data. The 12-bit signed real and imaginary components are
+ * converted to host endianness and sign-extended.
+ *
+ * @param pct 24-bit little-endian phase correction term.
+ *
+ * @return Real and imaginary terms as int16_t.
+ */
+static inline struct bt_le_cs_iq_sample bt_le_cs_parse_pct(const uint8_t pct[3])
+{
+	uint32_t sample = sys_get_le24(pct);
+	int16_t i;
+	int16_t q;
+	struct {
+		int16_t x: 12;
+	} s;
+	i = s.x = sample & BT_HCI_LE_CS_PCT_MASK;
+	q = s.x = (sample >> 12) & BT_HCI_LE_CS_PCT_MASK;
+	return (struct bt_le_cs_iq_sample){.i = i, .q = q};
+}
+
 /** @brief Set all valid channel map bits
  *
  * This command is used to enable all valid channels in a

samples/bluetooth/channel_sounding_test/CMakeLists.txt

@@ -0,0 +1,7 @@
+# SPDX-License-Identifier: Apache-2.0
+
+cmake_minimum_required(VERSION 3.20.0)
+find_package(Zephyr REQUIRED HINTS $ENV{ZEPHYR_BASE})
+project(channel_sounding_test)
+
+target_sources(app PRIVATE src/main.c)

samples/bluetooth/channel_sounding_test/README.rst

@@ -0,0 +1,28 @@
+.. _bluetooth-channel-sounding-test-sample:
+
+Bluetooth: Channel Sounding Testmode
+####################################
+
+Overview
+********
+
+This sample demonstrates how to use the CS test command.
+It can be used to override randomization of certain channel sounding parameters,
+experiment with different configurations, or evaluate the RF medium.
+
+A basic distance estimation method using phase rotations of the
+unmodulated tones is included.
+
+Requirements
+************
+
+* A board with BLE support
+* A controller that supports the Channel Sounding feature
+
+Building and Running
+********************
+
+This sample can be found under :zephyr_file:`samples/bluetooth/channel_sounding_test` in
+the Zephyr tree.
+
+See :zephyr:code-sample-category:`bluetooth` samples for details.

samples/bluetooth/channel_sounding_test/prj.conf

@@ -0,0 +1,23 @@
+CONFIG_CONSOLE=y
+CONFIG_CONSOLE_SUBSYS=y
+CONFIG_CONSOLE_HANDLER=y
+CONFIG_CONSOLE_GETCHAR=y
+
+CONFIG_BT=y
+CONFIG_BT_CENTRAL=y
+CONFIG_BT_PERIPHERAL=y
+CONFIG_BT_GATT_CLIENT=y
+CONFIG_BT_GATT_DYNAMIC_DB=y
+CONFIG_BT_CHANNEL_SOUNDING=y
+CONFIG_BT_CHANNEL_SOUNDING_TEST=y
+CONFIG_LOG=y
+
+CONFIG_BT_BUF_EVT_RX_SIZE=255
+CONFIG_BT_BUF_ACL_RX_SIZE=251
+CONFIG_BT_BUF_ACL_TX_SIZE=251
+CONFIG_BT_L2CAP_TX_MTU=247
+
+CONFIG_MAIN_STACK_SIZE=4096
+
+CONFIG_LOG_BUFFER_SIZE=2048
+CONFIG_CBPRINTF_FP_SUPPORT=y

samples/bluetooth/channel_sounding_test/sample.yaml

@@ -0,0 +1,11 @@
+sample:
+  name: Bluetooth Channel Sounding Test
+tests:
+  sample.bluetooth.channel_sounding_test:
+    harness: bluetooth
+    platform_allow:
+      - qemu_cortex_m3
+      - qemu_x86
+    tags: bluetooth
+    integration_platforms:
+      - qemu_cortex_m3