Bluetooth Shell

.. _bluetooth_shell:

Shell
#####

The Bluetooth Shell is an application based on the :ref:`shell_api` module. It offer a collection of
commands made to easily interact with the Bluetooth stack.

Bluetooth Shell Setup and Usage
*******************************

First you need to build and flash your board with the Bluetooth shell. For how to do that, see the
:ref:`getting_started`. The Bluetooth shell itself is located in
:zephyr_file:`tests/bluetooth/shell/`.

When it's done, connect to the CLI using your favorite serial terminal application. You should see
the following prompt:

.. code-block:: console

        uart:~$

For more details on general usage of the shell, see :ref:`shell_api`.

The first step is enabling Bluetooth. To do so, use the :code:`bt init` command. The following
message is printed to confirm Bluetooth has been initialized.

.. code-block:: console

        uart:~$ bt init
        Bluetooth initialized
        Settings Loaded
        [00:02:26.771,148] <inf> fs_nvs: nvs_mount: 8 Sectors of 4096 bytes
        [00:02:26.771,148] <inf> fs_nvs: nvs_mount: alloc wra: 0, fe8
        [00:02:26.771,179] <inf> fs_nvs: nvs_mount: data wra: 0, 0
        [00:02:26.777,984] <inf> bt_hci_core: hci_vs_init: HW Platform: Nordic Semiconductor (0x0002)
        [00:02:26.778,015] <inf> bt_hci_core: hci_vs_init: HW Variant: nRF52x (0x0002)
        [00:02:26.778,045] <inf> bt_hci_core: hci_vs_init: Firmware: Standard Bluetooth controller (0x00) Version 3.2 Build 99
        [00:02:26.778,656] <inf> bt_hci_core: bt_init: No ID address. App must call settings_load()
        [00:02:26.794,738] <inf> bt_hci_core: bt_dev_show_info: Identity: EB:BF:36:26:42:09 (random)
        [00:02:26.794,769] <inf> bt_hci_core: bt_dev_show_info: HCI: version 5.3 (0x0c) revision 0x0000, manufacturer 0x05f1
        [00:02:26.794,799] <inf> bt_hci_core: bt_dev_show_info: LMP: version 5.3 (0x0c) subver 0xffff


Identities
**********

Identities are a Zephyr host concept, allowing a single physical device to behave like multiple
logical Bluetooth devices.

The shell allows the creation of multiple identities, to a maximum that is set by the Kconfig symbol
:kconfig:option:`CONFIG_BT_ID_MAX`. To create a new identity, use :code:`bt id-create` command. You
can then use it by selecting it with its ID :code:`bt id-select <id>`. Finally, you can list all the
available identities with :code:`id-show`.

Scan for devices
****************

Start scanning by using the :code:`bt scan on` command. Depending on the environment you're in, you
may see a lot of lines printed on the shell. To stop the scan, run :code:`bt scan off`, the
scrolling should stop.

Here is an example of what you can expect:

.. code-block:: console

        uart:~$ bt scan on
        Bluetooth active scan enabled
        [DEVICE]: CB:01:1A:2D:6E:AE (random), AD evt type 0, RSSI -78  C:1 S:1 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        [DEVICE]: 20:C2:EE:59:85:5B (random), AD evt type 3, RSSI -62  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        [DEVICE]: E3:72:76:87:2F:E8 (random), AD evt type 3, RSSI -74  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        [DEVICE]: 1E:19:25:8A:CB:84 (random), AD evt type 3, RSSI -67  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        [DEVICE]: 26:42:F3:D5:A0:86 (random), AD evt type 3, RSSI -73  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        [DEVICE]: 0C:61:D1:B9:5D:9E (random), AD evt type 3, RSSI -87  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        [DEVICE]: 20:C2:EE:59:85:5B (random), AD evt type 3, RSSI -66  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        [DEVICE]: 25:3F:7A:EE:0F:55 (random), AD evt type 3, RSSI -83  C:0 S:0 D:0 SR:0 E:0 Prim: LE 1M, Secn: No packets, Interval: 0x0000 (0 us), SID: 0xff
        uart:~$ bt scan off
        Scan successfully stopped

As you can see, this can lead to a high number of results. To reduce that number and easily find a
specific device, you can enable scan filters. There are four types of filters: by name, by RSSI, by
address and by periodic advertising interval. To apply a filter, use the :code:`bt scan-set-filter`
command followed by the type of filters. You can add multiple filters by using the commands again.

For example, if you want to look only for devices with the name *test shell*:

.. code-block:: console

        uart:~$ bt scan-filter-set name "test shell"

Or if you want to look for devices at a very close range:

.. code-block:: console

        uart:~$ bt scan-filter-set rssi -40
        RSSI cutoff set at -40 dB

Finally, if you want to remove all filters:

.. code-block:: console

        uart:~$ bt scan-filter-clear all

You can use the command :code:`bt scan on` to create an *active* scanner, meaning that the scanner
will ask the advertisers for more information by sending a *scan request* packet. Alternatively, you
can create a *passive scanner* by using the :code:`bt scan passive` command, so the scanner will not
ask the advertiser for more information.

Connecting to a device
**********************

To connect to a device, you need to know its address and type of address and use the
:code:`bt connect` command with the address and the type as arguments.

Here is an example:

.. code-block:: console

        uart:~$ bt connect 52:84:F6:BD:CE:48 random
        Connection pending
        Connected: 52:84:F6:BD:CE:48 (random)
        Remote LMP version 5.3 (0x0c) subversion 0xffff manufacturer 0x05f1
        LE Features: 0x000000000001412f
        LE PHY updated: TX PHY LE 2M, RX PHY LE 2M
        LE conn  param req: int (0x0018, 0x0028) lat 0 to 42
        LE conn param updated: int 0x0028 lat 0 to 42

You can list the active connections of the shell using the :code:`bt connections` command. The shell
maximum number of connections is defined by :kconfig:option:`CONFIG_BT_MAX_CONN`. You can disconnect
from a connection with the
:code:`bt disconnect <address: XX:XX:XX:XX:XX:XX> <type: (public|random)>` command.

.. note::

        If you were scanning just before, you can connect to the last scanned device by
        simply running the :code:`bt connect` command.

        Alternatively, you can use the :code:`bt connect-name <name>` command to automatically
        enable scanning with a name filter and connect to the first match.

Advertising
***********

Begin advertising by using the :code:`bt advertise on` command. This will use the default parameters
and advertise a resolvable private address with the name of the device. You can choose to use the
identity address instead by running the :code:`bt advertise on identity` command. To stop
advertising use the :code:`bt advertise off` command.

To enable more advanced features of advertising, you should create an advertiser using the
:code:`bt adv-create` command. Parameters for the advertiser can be passed either at the creation of
it or by using the :code:`bt adv-param` command. To begin advertising with this newly created
advertiser, use the :code:`bt adv-start` command, and then the :code:`bt adv-stop` command to stop
advertising.

When using the custom advertisers, you can choose if it will be connectable or scannable. This leads
to four options: :code:`conn-scan`, :code:`conn-nscan`, :code:`nconn-scan` and :code:`nconn-nscan`.
Those parameters are mandatory when creating an advertiser or updating its parameters.

For example, if you want to create a connectable and scannable advertiser and start it:

.. code-block:: console

        uart:~$ bt adv-create conn-scan
        Created adv id: 0, adv: 0x200022f0
        uart:~$ bt adv-start
        Advertiser[0] 0x200022f0 set started

You may notice that with this, the custom advertiser does not advertise the device name; you need to
add it. Continuing from the previous example:

.. code-block:: console

        uart:~$ bt adv-stop
        Advertiser set stopped
        uart:~$ bt adv-data dev-name
        uart:~$ bt adv-start
        Advertiser[0] 0x200022f0 set started

You should now see the name of the device in the advertising data. You can also set a custom name by
using :code:`name <custom name>` instead of :code:`dev-name`. It is also possible to set the
advertising data manually with the :code:`bt adv-data` command. The following example shows how
to set the advertiser name with it using raw advertising data:

.. code-block:: console

        uart:~$ bt adv-create conn-scan
        Created adv id: 0, adv: 0x20002348
        uart:~$ bt adv-data 1009426C7565746F6F74682D5368656C6C
        uart:~$ bt adv-start
        Advertiser[0] 0x20002348 set started

The data must be formatted according to the Bluetooth Core Specification (see version 5.3, vol. 3,
part C, 11). In this example, the first octet is the size of the data (the data and one octet for
the data type), the second one is the type of data, ``0x09`` is the Complete Local Name and the
remaining data are the name in ASCII. So, on the other device you should see the name
*Bluetooth-Shell*.

When advertising, if others devices use an *active* scanner, you may receive *scan request* packets.
To visualize those packets, you can add :code:`scan-reports` to the parameters of your advertiser.

Directed Advertising
====================

It is possible to use directed advertising on the shell if you want to reconnect to a device. The
following example demonstrates how to create a directed advertiser with the address specified right
after the parameter :code:`directed`. The :code:`low` parameter indicates that we want to use the
low duty cycle mode, and the :code:`dir-rpa` parameter is required if the remote device is
privacy-enabled and supports address resolution of the target address in directed advertisement.

.. code-block:: console

        uart:~$ bt adv-create conn-scan directed D7:54:03:CE:F3:B4 random low dir-rpa
        Created adv id: 0, adv: 0x20002348

After that, you can start the advertiser and then the target device will be able to reconnect.

Extended Advertising
====================

Let's now have a look at some extended advertising features. To enable extended advertising, use the
`ext-adv` parameter.

.. code-block:: console

        uart:~$ bt adv-create conn-nscan ext-adv name-ad
        Created adv id: 0, adv: 0x200022f0
        uart:~$ bt adv-start
        Advertiser[0] 0x200022f0 set started

This will create an extended advertiser, that is connectable and non-scannable.

Encrypted Advertising Data
==========================

Zephyr has support for the Encrypted Advertising Data feature. The :code:`bt encrypted-ad`
sub-commands allow managing the advertising data of a given advertiser.

To encrypt the advertising data, key materials need to be provided, that can be done with :code:`bt
encrypted-ad set-keys <session key> <init vector>`. The session key is 16 bytes long and the
initialisation vector is 8 bytes long.

You can add advertising data by using :code:`bt encrypted-ad add-ad` and :code:`bt encrypted-ad
add-ead`. The former will take add one advertising data structure (as defined in the Core
Specification), when the later will read the given data, encrypt them and then add the generated
encrypted advertising data structure. It's possible to mix encrypted and non-encrypted data, when
done adding advertising data, :code:`bt encrypted-ad commit-ad` can be used to apply the change to
the data to the selected advertiser. After that the advertiser can be started as described
previously. It's possible to clear the advertising data by using :code:`bt encrypted-ad clear-ad`.

On the Central side, it's possible to decrypt the received encrypted advertising data by setting the
correct keys material as described earlier and then enabling the decrypting of the data with
:code:`bt encrypted-ad decrypt-scan on`.

.. note::

        To see the advertising data in the scan report :code:`bt scan-verbose-output` need to be
        enabled.

.. note::

        It's possible to increase the length of the advertising data by increasing the value of
        :kconfig:option:`CONFIG_BT_CTLR_ADV_DATA_LEN_MAX` and
        :kconfig:option:`CONFIG_BT_CTLR_SCAN_DATA_LEN_MAX`.

Here is a simple example demonstrating the usage of EAD:

.. tabs::

        .. group-tab:: Peripheral

                .. code-block:: console

                        uart:~$ bt init
                        ...
                        uart:~$ bt adv-create conn-nscan ext-adv
                        Created adv id: 0, adv: 0x81769a0
                        uart:~$ bt encrypted-ad set-keys 9ba22d3824efc70feb800c80294cba38 2e83f3d4d47695b6
                        session key set to:
                        00000000: 9b a2 2d 38 24 ef c7 0f  eb 80 0c 80 29 4c ba 38 |..-8$... ....)L.8|
                        initialisation vector set to:
                        00000000: 2e 83 f3 d4 d4 76 95 b6                          |.....v..         |
                        uart:~$ bt encrypted-ad add-ad 06097368656C6C
                        uart:~$ bt encrypted-ad add-ead 03ffdead03ffbeef
                        uart:~$ bt encrypted-ad commit-ad
                        Advertising data for Advertiser[0] 0x81769a0 updated.
                        uart:~$ bt adv-start
                        Advertiser[0] 0x81769a0 set started

        .. group-tab:: Central

                .. code-block:: console

                        uart:~$ bt init
                        ...
                        uart:~$ bt scan-verbose-output on
                        uart:~$ bt encrypted-ad set-keys 9ba22d3824efc70feb800c80294cba38 2e83f3d4d47695b6
                        session key set to:
                        00000000: 9b a2 2d 38 24 ef c7 0f  eb 80 0c 80 29 4c ba 38 |..-8$... ....)L.8|
                        initialisation vector set to:
                        00000000: 2e 83 f3 d4 d4 76 95 b6                          |.....v..         |
                        uart:~$ bt encrypted-ad decrypt-scan on
                        Received encrypted advertising data will now be decrypted using provided key materials.
                        uart:~$ bt scan on
                        Bluetooth active scan enabled
                        [DEVICE]: 68:49:30:68:49:30 (random), AD evt type 5, RSSI -59   shell C:1 S:0 D:0 SR:0 E:1 Prim: LE 1M, Secn: LE 2M, Interval: 0x0000 (0 us), SID: 0x0
                                [SCAN DATA START - EXT_ADV]
                                Type 0x09:    shell
                                Type 0x31: Encrypted Advertising Data: 0xe2, 0x17, 0xed, 0x04, 0xe7, 0x02, 0x1d, 0xc9, 0x40, 0x07, uart:~0x18, 0x90, 0x6c, 0x4b, 0xfe, 0x34, 0xad
                                [START DECRYPTED DATA]
                                Type 0xff: 0xde, 0xad
                                Type 0xff: 0xbe, 0xef
                                [END DECRYPTED DATA]
                                [SCAN DATA END]
                        ...

Filter Accept List
******************

It's possible to create a list of allowed addresses that can be used to
connect to those addresses automatically. Here is how to do it:

.. code-block:: console

        uart:~$ bt fal-add 47:38:76:EA:29:36 random
        uart:~$ bt fal-add 66:C8:80:2A:05:73 random
        uart:~$ bt fal-connect on

The shell will then connect to the first available device. In the example, if both devices are
advertising at the same time, we will connect to the first address added to the list.

The Filter Accept List can also be used for scanning or advertising by using the option :code:`fal`.
For example, if we want to scan for a bunch of selected addresses, we can set up a Filter Accept
List:

.. code-block:: console

        uart:~$ bt fal-add 65:4B:9E:83:AF:73 random
        uart:~$ bt fal-add 73:72:82:B4:8F:B9 random
        uart:~$ bt fal-add 5D:85:50:1C:72:64 random
        uart:~$ bt scan on fal

You should see only those three addresses reported by the scanner.

Enabling security
*****************

When connected to a device, you can enable multiple levels of security, here is the list for
Bluetooth LE:

* **1** No encryption and no authentication;
* **2** Encryption and no authentication;
* **3** Encryption and authentication;
* **4** Bluetooth LE Secure Connection.

To enable security, use the :code:`bt security <level>` command. For levels requiring authentication
(level 3 and above), you must first set the authentication method. To do it, you can use the
:code:`bt auth all` command. After that, when you will set the security level, you will be asked to
confirm the passkey on both devices. On the shell side, do it with the command
:code:`bt auth-passkey-confirm`.

Pairing
=======

Enabling authentication requires the devices to be bondable. By default the shell is bondable. You
can make the shell not bondable using :code:`bt bondable off`. You can list all the devices you are
paired with using the command :code:`bt bonds`.

The maximum number of paired devices is set using :kconfig:option:`CONFIG_BT_MAX_PAIRED`. You can
remove a paired device using :code:`bt clear <address: XX:XX:XX:XX:XX:XX> <type: (public|random)>`
or remove all paired devices with the command :code:`bt clear all`.

GATT
****

The following examples assume that you have two devices already connected.

To perform service discovery on the client side, use the :code:`gatt discover` command. This should
print all the services that are available on the GATT server.

On the server side, you can register pre-defined test services using the :code:`gatt register`
command. When done, you should see the newly added services on the client side when running the
discovery command.

You can now subscribe to those new services on the client side. Here is an example on how to
subscribe to the test service:

.. code-block:: console

        uart:~$ gatt subscribe 26 25
        Subscribed

The server can now notify the client with the command :code:`gatt notify`.

Another option available through the GATT command is initiating the MTU exchange. To do it, use the
:code:`gatt exchange-mtu` command. To update the shell maximum MTU, you need to update Kconfig
symbols in the configuration file of the shell. For more details, see
:ref:`bluetooth_mtu_update_sample`.

L2CAP
*****

The :code:`l2cap` command exposes parts of the L2CAP API. The following example shows how to
register a LE PSM, connect to it from another device and send 3 packets of 14 octets each.

The example assumes that the two devices are already connected.

On device A, register the LE PSM:

.. code-block:: console

        uart:~$ l2cap register 29
        L2CAP psm 41 sec_level 1 registered

On device B, connect to the registered LE PSM and send data:

.. code-block:: console

        uart:~$ l2cap connect 29
        Chan sec: 1
        L2CAP connection pending
        Channel 0x20000210 connected
        Channel 0x20000210 status 1
        uart:~$ l2cap send 3 14
        Rem 2
        Rem 1
        Rem 0
        Outgoing data channel 0x20000210 transmitted
        Outgoing data channel 0x20000210 transmitted
        Outgoing data channel 0x20000210 transmitted

On device A, you should have received the data:

.. code-block:: console

        Incoming conn 0x20002398
        Channel 0x20000210 status 1
        Channel 0x20000210 connected
        Channel 0x20000210 requires buffer
        Incoming data channel 0x20000210 len 14
        00000000: ff ff ff ff ff ff ff ff  ff ff ff ff ff ff       |........ ......  |
        Channel 0x20000210 requires buffer
        Incoming data channel 0x20000210 len 14
        00000000: ff ff ff ff ff ff ff ff  ff ff ff ff ff ff       |........ ......  |
        Channel 0x20000210 requires buffer
        Incoming data channel 0x20000210 len 14
        00000000: ff ff ff ff ff ff ff ff  ff ff ff ff ff ff       |........ ......  |

A2DP
*****
The :code:`a2dp` command exposes parts of the A2DP API.

The following examples assume that you have two devices already connected.

Here is a example connecting two devices:
 * Source and Sink sides register a2dp callbacks. using :code:`a2dp register_cb`.
 * Source and Sink sides register stream endpoints. using :code:`a2dp register_ep source sbc` and :code:`a2dp register_ep sink sbc`.
 * Source establish A2dp connection. It will create the AVDTP Signaling and Media L2CAP channels. using :code:`a2dp connect`.
 * Source and Sink side can discover remote device's stream endpoints. using :code:`a2dp discover_peer_eps`
 * Source or Sink configure the stream to create the stream after discover remote's endpoints. using :code:`a2dp configure`.
 * Source or Sink establish the stream. using :code:`a2dp establish`.
 * Source or Sink start the media. using :code:`a2dp start`.
 * Source test the media sending. using :code:`a2dp send_media` to send one test packet data.

.. tabs::

        .. group-tab:: Device A (Audio Source Side)

                .. code-block:: console

                        uart:~$ a2dp register_cb
                        success
                        uart:~$ a2dp register_ep source sbc
                        SBC source endpoint is registered
                        uart:~$ a2dp connect
                        Bonded with XX:XX:XX:XX:XX:XX
                        Security changed: XX:XX:XX:XX:XX:XX level 2
                        a2dp connected
                        uart:~$ a2dp discover_peer_eps
                        endpoint id: 1, (sink), (idle):
                          codec type: SBC
                          sample frequency:
                                  44100
                                  48000
                          channel mode:
                                  Mono
                                  Stereo
                                  Joint-Stereo
                          Block Length:
                                  16
                          Subbands:
                                  8
                          Allocation Method:
                                  Loudness
                          Bitpool Range: 18 - 35
                        uart:~$ a2dp configure
                        success to configure
                        stream configured
                        uart:~$ a2dp establish
                        success to establish
                        stream established
                        uart:~$ a2dp start
                        success to start
                        stream started
                        uart:~$ a2dp send_media
                        frames num: 1, data length: 160
                        data: 1, 2, 3, 4, 5, 6 ......

        .. group-tab:: Device B (Audio Sink Side)

                .. code-block:: console

                        uart:~$ a2dp register_cb
                        success
                        uart:~$ a2dp register_ep sink sbc
                        SBC sink endpoint is registered
                        <after a2dp connect>
                        Connected: XX:XX:XX:XX:XX:XX
                        Bonded with XX:XX:XX:XX:XX:XX
                        Security changed: XX:XX:XX:XX:XX:XX level 2
                        a2dp connected
                        <after a2dp configure of source side>
                        receive requesting config and accept
                        SBC configure success
                        sample rate 44100Hz
                        stream configured
                        <after a2dp establish of source side>
                        receive requesting establishment and accept
                        stream established
                        <after a2dp start of source side>
                        receive requesting start and accept
                        stream started
                        <after a2dp send_media of source side>
                        received, num of frames: 1, data length: 160
                        data: 1, 2, 3, 4, 5, 6 ......
                        ...

Logging
*******

You can configure the logging level per module at runtime. This depends on the maximum logging level
that is compiled in. To configure, use the :code:`log` command. Here are some examples:

* List the available modules and their current logging level

.. code-block:: console

        uart:~$ log status

* Disable logging for *bt_hci_core*

.. code-block:: console

        uart:~$ log disable bt_hci_core

* Enable error logs for *bt_att* and *bt_smp*

.. code-block:: console

        uart:~$ log enable err bt_att bt_smp

* Disable logging for all modules

.. code-block:: console

        uart:~$ log disable

* Enable warning logs for all modules

.. code-block:: console

        uart:~$ log enable wrn