README.rst

Bluetooth: Channel Sounding Initiator with Ranging Requestor

• Requirements
• Overview
• User interface
• Building and running
  • Testing
• Dependencies

This sample demonstrates how to use the ranging service to request ranging data from a server. It also provides a basic distance estimation algorithm to demonstrate the IQ data handling. The accuracy is not representative for Channel Sounding and should be replaced if accuracy is important.

Requirements

The sample supports the following development kits:

.. table-from-sample-yaml::

The sample also requires a device running a Channel Sounding Reflector with Ranging Responder to connect to, such as the :ref:`channel_sounding_ras_reflector` sample.

Overview

The sample demonstrates a basic Bluetooth® Low Energy Central role functionality that acts as a GATT Ranging Requestor client and configures the Channel Sounding initiator role. Regular Channel Sounding procedures are set up, local subevent data is stored, and peer ranging data is fetched.

A basic distance estimation algorithm is included in the sample. The mathematical representations described in `Distance estimation based on phase and amplitude information`_ and `Distance estimation based on RTT packets`_ are used as the basis for this algorithm.

User interface

The sample does not require user input and will scan for a device advertising with the GATT Ranging Service UUID. The first LED on the development kit will be lit when a connection has been established.

Building and running

Testing

After programming the sample to your development kit, you can test it by connecting to another device programmed with a Channel Sounding Reflector role with Ranging Responder, such as the :ref:`channel_sounding_ras_reflector` sample.

1. |connect_terminal_specific|

2. Reset both kits.

3. Wait until the scanner detects the Peripheral. In the terminal window, check for information similar to the following:

   I: Filters matched. Address: XX:XX:XX:XX:XX:XX (random) connectable: 1
   I: Connecting
   I: Connected to XX:XX:XX:XX:XX:XX (random) (err 0x00)
   I: Security changed: XX:XX:XX:XX:XX:XX (random) level 2
   I: MTU exchange success (498)
   I: The discovery procedure succeeded
   I: CS capability exchange completed.
   I: CS config creation complete. ID: 0
   I: CS security enabled.
   I: CS procedures enabled.
   I: Subevent result callback 0
   I: Ranging data ready 0
   I: Ranging data get completed for ranging counter 0
   I: Estimated distance to reflector:
   I: - Round-Trip Timing method: X.XXXXX meters (derived from X samples)
   I: - Phase-Based Ranging method: X.XXXXX meters (derived on antenna path A from X samples)
   

Dependencies

This sample uses the following |NCS| libraries:

• :ref:`dk_buttons_and_leds_readme`
• :file:`include/bluetooth/gatt_dm.h`
• :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/cs.h`