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doc/connectivity/bluetooth/bluetooth-tools.rst

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.. _bluetooth-tools:

Tools

This page lists and describes tools that can be used to assist during Bluetooth stack or application development in order to help, simplify and speed up the development process.

.. contents:: :local: :depth: 2

.. _bluetooth-mobile-apps:

Mobile applications


It is often useful to make use of existing mobile applications to interact with hardware running Zephyr, to test functionality without having to write any additional code or requiring extra hardware.

The recommended mobile applications for interacting with Zephyr are:

  • Android:

    • nRF Connect for Android_
    • nRF Mesh for Android_
    • LightBlue for Android_
  • iOS:

    • nRF Connect for iOS_
    • nRF Mesh for iOS_
    • LightBlue for iOS_

.. _bluetooth_bluez:

Using BlueZ with Zephyr


The Linux Bluetooth Protocol Stack, BlueZ, comes with a very useful set of tools that can be used to debug and interact with Zephyr's Bluetooth Host and Controller. In order to benefit from these tools you will need to make sure that you are running a recent version of the Linux Kernel and BlueZ:

  • Linux Kernel 4.10+
  • BlueZ 4.45+

Additionally, some of the BlueZ tools might not be bundled by default by your Linux distribution. If you need to build BlueZ from scratch to update to a recent version or to obtain all of its tools you can follow the steps below:

.. code-block:: console

git clone git://git.kernel.org/pub/scm/bluetooth/bluez.git cd bluez ./bootstrap-configure --disable-android --disable-midi make

You can then find :file:btattach, :file:btmgt and :file:btproxy in the :file:tools/ folder and :file:btmon in the :file:monitor/ folder.

You'll need to enable BlueZ's experimental features so you can access its most recent Bluetooth functionality. Do this by editing the file :file:/lib/systemd/system/bluetooth.service and making sure to include the :literal:-E option in the daemon's execution start line:

.. code-block:: console

ExecStart=/usr/libexec/bluetooth/bluetoothd -E

Finally, reload and restart the daemon:

.. code-block:: console

sudo systemctl daemon-reload sudo systemctl restart bluetooth

.. _bluetooth_qemu_native:

Running on QEMU or native_sim


It's possible to run Bluetooth applications using either the :ref:QEMU emulator<application_run_qemu> or :zephyr:board:native_sim <native_sim>.

In either case, a Bluetooth controller needs to be exported from the host OS (Linux) to the emulator. For this purpose you will need some tools described in the :ref:bluetooth_bluez section.

Using the Host System Bluetooth Controller

The host OS's Bluetooth controller is connected in the following manner:

  • To the second QEMU serial line using a UNIX socket. This socket gets used with the help of the QEMU option :literal:-serial unix:/tmp/bt-server-bredr. This option gets passed to QEMU through :makevar:QEMU_EXTRA_FLAGS automatically whenever an application has enabled Bluetooth support.
  • To :ref:native_sim's BT User Channel driver <nsim_bt_host_cont> through the use of a command-line option passed to the native_sim executable: --bt-dev=hci0

On the host side, BlueZ allows you to export its Bluetooth controller through a so-called user channel for QEMU and :zephyr:board:native_sim <native_sim> to use.

.. note:: You only need to run btproxy when using QEMU. native_sim handles the UNIX socket proxying automatically

If you are using QEMU, in order to make the Controller available you will need one additional step using btproxy:

#. Make sure that the Bluetooth controller is down

#. Use the btproxy tool to open the listening UNIX socket, type:

.. code-block:: console

  sudo tools/btproxy -u -i 0
  Listening on /tmp/bt-server-bredr

You might need to replace :literal:-i 0 with the index of the Controller you wish to proxy.

If you see Received unknown host packet type 0x00 when running QEMU, then add :literal:-z to the btproxy command line to ignore any null bytes transmitted at startup.

Once the hardware is connected and ready to use, you can then proceed to building and running a sample:

  • Choose one of the Bluetooth sample applications located in :literal:samples/bluetooth.

  • To run a Bluetooth application in QEMU, type:

    .. zephyr-app-commands:: :zephyr-app: samples/bluetooth/<sample> :host-os: unix :board: qemu_x86 :goals: run :compact:

    Running QEMU now results in a connection with the second serial line to the :literal:bt-server-bredr UNIX socket, letting the application access the Bluetooth controller.

  • To run a Bluetooth application in :zephyr:board:native_sim <native_sim>, first build it:

    .. zephyr-app-commands:: :zephyr-app: samples/bluetooth/<sample> :host-os: unix :board: native_sim :goals: build :compact:

    And then run it with::

    $ sudo ./build/zephyr/zephyr.exe --bt-dev=hci0

Using a Zephyr-based Bluetooth Controller

Depending on which hardware you have available, you can choose between two transports when building a single-mode, Zephyr-based Bluetooth Controller:

  • UART: Use the :zephyr:code-sample:bluetooth_hci_uart sample and follow the instructions in :ref:bluetooth-hci-uart-qemu-posix.
  • USB: Use the :zephyr:code-sample:bluetooth_hci_usb sample and then treat it as a Host System Bluetooth Controller (see previous section)

.. _bluetooth-hci-tracing:

HCI Tracing

When running the Host on a computer connected to an external Controller, it is very useful to be able to see the full log of exchanges between the two, in the format of a :ref:bluetooth-hci log. In order to see those logs, you can use the built-in btmon tool from BlueZ:

.. code-block:: console

$ btmon

The output looks like this::

= New Index: 00:00:00:00:00:00 (Primary,Virtual,Control) 0.274200 = Open Index: 00:00:00:00:00:00 0.274500 < HCI Command: Reset (0x03|0x0003) plen 0 #1 0.274600

HCI Event: Command Complete (0x0e) plen 4 #2 0.274700 Reset (0x03|0x0003) ncmd 1 Status: Success (0x00) < HCI Command: Read Local Supported Features (0x04|0x0003) plen 0 #3 0.274800 HCI Event: Command Complete (0x0e) plen 12 #4 0.274900 Read Local Supported Features (0x04|0x0003) ncmd 1 Status: Success (0x00) Features: 0x00 0x00 0x00 0x00 0x60 0x00 0x00 0x00 BR/EDR Not Supported LE Supported (Controller)

.. _bluetooth-embedded-hci-tracing:

Embedded HCI tracing

When running both Host and Controller in actual Integrated Circuits, you will only see normal log messages on the console by default, without any way of accessing the HCI traffic between the Host and the Controller. However, there is a special Bluetooth logging mode that converts the console to use a binary protocol that interleaves both normal log messages as well as the HCI traffic.

Set the following Kconfig options to enable this protocol before building your application:

.. code-block:: cfg

CONFIG_BT_DEBUG_MONITOR_UART=y CONFIG_UART_CONSOLE=n

  • Setting :kconfig:option:CONFIG_BT_DEBUG_MONITOR_UART activates the formatting
  • Clearing :kconfig:option:CONFIG_UART_CONSOLE makes the UART unavailable for the system console. E.g. for printk and the :kconfig:option:boot banner <CONFIG_BOOT_BANNER>

To decode the binary protocol that will now be sent to the console UART you need to use the btmon tool from :ref:BlueZ <bluetooth_bluez>:

.. code-block:: console

$ btmon --tty <console TTY> --tty-speed 115200

If UART is not available (or you still want non-binary logs), you can set :kconfig:option:CONFIG_BT_DEBUG_MONITOR_RTT instead, which will use Segger RTT. For example, if trying to connect to a nRF52840DK with S/N 683578642:

.. code-block:: console

$ btmon --jlink nRF52840_xxAA,683578642

.. _bluetooth_virtual_posix:

Running on a Virtual Controller and native_sim


An alternative to a Bluetooth physical controller is the use of a virtual controller. This controller can be connected over an HCI TCP server. This TCP server must support the HCI H4 protocol. In comparison to the physical controller variant, the virtual controller allows to test a Zephyr application running on the native boards without a physical Bluetooth controller.

The main use case for a virtual controller is to do Bluetooth connectivity tests without the need of Bluetooth hardware. This allows to automate Bluetooth integration tests with external applications such as a Bluetooth gateway or a mobile application.

To demonstrate this functionality an example is given to interact with a virtual controller. For this purpose, the experimental python module Bumble_ from Google is used as it allows to create a TCP Bluetooth virtual controller and connect with the Zephyr Bluetooth host. To install bumble follow the Bumble Getting Started Guide_.

.. note:: If your Zephyr application requires the use of the HCI LE Set extended commands, install the branch controller-extended-advertising from Bumble.

Android Emulator

You can test the virtual controller by connecting a Bluetooth Zephyr application to the Android Emulator_.

To connect your application to the Android Emulator follow the next steps:

#. Build your Zephyr application and disable the HCI ACL flow
   control (i.e. ``CONFIG_BT_HCI_ACL_FLOW_CONTROL=n``) as the
   virtual controller from android does not support it at the moment.

#. Install Android Emulator version >= 33.1.4.0. The easiest way to do this is by installing
   the latest `Android Studio Preview`_ version.

#. Create a new Android Virtual Device (AVD) with the `Android Device Manager`_. The AVD should use at least SDK API 34.

#. Run the Android Emulator via terminal as follows:

   ``emulator avd YOUR_AVD -packet-streamer-endpoint default``

#. Create a Bluetooth bridge between the Zephyr application and
   the virtual controller from Android Emulator with the `Bumble`_ utility ``hci-bridge``.

   ``bumble-hci-bridge tcp-server:_:1234 android-netsim``

   This command will create a TCP server bridge on the local host IP address ``127.0.0.1``
   and port number ``1234``.

#. Run the Zephyr application and connect to the TCP server created in the last step.

   ``./zephyr.exe --bt-dev=127.0.0.1:1234``

After following these steps the Zephyr application will be available to the Android Emulator over the virtual Bluetooth controller that was bridged with Bumble. You can verify that the Zephyr application can communicate over Bluetooth by opening the Bluetooth settings in your AVD and scanning for your Zephyr application device. To test this you can build the Bluetooth peripheral samples such as :zephyr:code-sample:ble_peripheral_hr or :zephyr:code-sample:ble_peripheral_dis.

.. _bluetooth_ctlr_bluez:

Using Zephyr-based Controllers with BlueZ


If you want to test a Zephyr-powered Bluetooth Controller using BlueZ's Bluetooth Host, you will need a few tools described in the :ref:bluetooth_bluez section. Once you have installed the tools you can then use them to interact with your Zephyr-based controller:

.. code-block:: console

  sudo tools/btmgmt --index 0
  [hci0]# auto-power
  [hci0]# find -l

You might need to replace :literal:--index 0 with the index of the Controller you wish to manage. Additional information about :file:btmgmt can be found in its manual pages.

.. _nRF Connect for Android: https://play.google.com/store/apps/details?id=no.nordicsemi.android.mcp&hl=en .. _nRF Connect for iOS: https://itunes.apple.com/us/app/nrf-connect/id1054362403 .. _LightBlue for Android: https://play.google.com/store/apps/details?id=com.punchthrough.lightblueexplorer&hl=en_US .. _LightBlue for iOS: https://itunes.apple.com/us/app/lightblue-explorer/id557428110 .. _nRF Mesh for Android: https://play.google.com/store/apps/details?id=no.nordicsemi.android.nrfmeshprovisioner&hl=en .. _nRF Mesh for iOS: https://itunes.apple.com/us/app/nrf-mesh/id1380726771 .. _Bumble: https://github.com/google/bumble .. _Bumble Getting Started Guide: https://google.github.io/bumble/getting_started.html .. _Android Emulator: https://developer.android.com/studio/run/emulator .. _Android Device Manager: https://developer.android.com/studio/run/managing-avds .. _Android Studio Preview: https://developer.android.com/studio/preview