.. _nrf53_audio_app: nRF5340 Audio ############# .. contents:: :local: :depth: 2 The nRF5340 Audio application demonstrates audio playback over isochronous channels (ISO) using LC3 codec compression and decompression, as per `Bluetooth® LE Audio specifications`_. It is developed for use with the :ref:`nRF5340 Audio development kit `. In its default configuration, the application requires the :ref:`LC3 software codec `. The application also comes with various tools, including the :file:`buildprog.py` Python script that simplifies building and programming the firmware. .. note:: There is an ongoing process of restructuring the nRF5340 Audio application project. Several drivers and modules within the application folder are being moved to more suitable locations in the |NCS| or Zephyr. Before this process has finished, developing out-of-tree applications can be more complex. .. _nrf53_audio_app_overview_features: Feature support matrix The following table lists features of the nRF5340 Audio application and their respective limitations and maturity level. For an explanation of the maturity levels, see :ref:`Software maturity levels `. .. note:: Features not listed are not supported. .. include:: /software_maturity.rst :start-after: software_maturity_application_nrf5340audio_table: :end-before: software_maturity_protocol .. _nrf53_audio_app_overview: Overview ******** The application can work as a gateway or a headset. The gateway receives the audio data from external sources (USB or I2S) and forwards it to one or more headsets. The headset is a receiver device that plays back the audio it gets from the gateway. It is also possible to enable a bidirectional mode where one gateway can send and receive audio to and from one or two headsets at the same time. Both device types use the same code base, but different firmware, and you need both types of devices for testing the application. Gateways and headsets can both run in one of the available application modes, either the *connected isochronous stream* (CIS) mode or in the *broadcast isochronous stream* (BIS) mode. The CIS mode is the default mode of the application. Changing configuration related to the device type and the application modes requires rebuilding the firmware and reprogramming the development kits. Regardless of the configuration, the application handles the audio data in the following manner: 1. The gateway receives audio data from the audio source over USB or I2S. #. The gateway processes the audio data in its application core, which channels the data through the application layers: a. Audio data is sent to the synchronization module (I2S-based firmware) or directly to the software codec (USB-based firmware). #. Audio data is encoded by the software codec. #. Encoded audio data is sent to the Bluetooth LE Host. #. The host sends the encoded audio data to the LE Audio Controller Subsystem for nRF53 on the network core. #. The subsystem forwards the audio data to the hardware radio and sends it to the headset devices, as per the LE Audio specifications. #. The headsets receive the encoded audio data on their hardware radio on the network core side. #. The LE Audio Controller Subsystem for nRF53 running on each of the headsets sends the encoded audio data to the Bluetooth LE Host on the headsets' application core. #. The headsets process the audio data in their application cores, which channel the data through the application layers: a. Audio data is sent to the stream control module and placed in a FIFO buffer. #. Audio data is sent from the FIFO buffer to the synchronization module (headsets only use I2S-based firmware). #. Audio data is decoded by the software codec. #. Decoded audio data is sent to the hardware audio output over I2S. In the `I2S-based firmware for gateway and headsets`_, sending the audio data through the application layers includes a mandatory synchronization step using the synchronization module. This proprietary module ensures that the audio is played at the same time with the correct speed. For more information, see `Synchronization module overview`_. .. _nrf53_audio_app_overview_modes: Application modes ================= The application can work either in the *connected isochronous stream* (CIS) mode or in the *broadcast isochronous stream* (BIS) mode, depending on the chosen firmware configuration. .. figure:: /images/octave_application_topologies.svg :alt: CIS and BIS mode overview CIS and BIS mode overview Connected Isochronous Stream (CIS) CIS is a bidirectional communication protocol that allows for sending separate connected audio streams from a source device to one or more receivers. The gateway can send the audio data using both the left and the right ISO channels at the same time, allowing for stereophonic sound reproduction with synchronized playback. This is the default configuration of the nRF5340 Audio application. In this configuration, you can use the nRF5340 Audio development kit in the role of the gateway, the left headset, or the right headset. In the current version of the nRF5340 Audio application, the CIS mode offers both unidirectional and bidirectional communication. In the bidirectional communication, the headset device will send audio from the on-board PDM microphone. See `Selecting the CIS bidirectional communication`_ for more information. You can also enable a walkie-talkie demonstration. In this demonstration, the gateway device will send audio from the on-board PDM microphone instead of using USB or the line-in. See `Enabling the walkie-talkie demo`_ for more information. Broadcast Isochronous Stream (BIS) BIS is a unidirectional communication protocol that allows for broadcasting one or more audio streams from a source device to an unlimited number of receivers that are not connected to the source. In this configuration, you can use the nRF5340 Audio development kit in the role of the gateway or as one of the headsets. Use multiple nRF5340 Audio development kits to test BIS having multiple receiving headsets. .. note:: In the BIS mode, you can use any number of nRF5340 Audio development kits as receivers. The audio quality for both modes does not change, although the processing time for stereo can be longer. .. _nrf53_audio_app_overview_architecture: Firmware architecture ===================== The following figure illustrates the software layout for the nRF5340 Audio application: .. figure:: /images/octave_application_structure_generic.svg :alt: nRF5340 Audio high-level design (overview) nRF5340 Audio high-level design (overview) The network core of the nRF5340 SoC runs the *LE Audio Controller Subsystem for nRF53*. This subsystem is a Bluetooth LE Controller that is custom-made for the application. It is responsible for receiving the audio stream data from hardware layers and forwarding the data to the Bluetooth LE host on the application core. The subsystem implements the lower layers of the Bluetooth Low Energy software stack and follows the LE Audio specification requirements. The application core runs both the Bluetooth LE Host from Zephyr and the application layer. The application layer is composed of a series of modules from different sources. These modules include the following major ones: * Peripheral modules from the |NCS|: * I2S * USB * SPI * TWI/I2C * UART (debug) * Timer * LC3 encoder/decoder * Application-specific Bluetooth modules for handling the Bluetooth connection: * :file:`le_audio_cis_gateway.c` or :file:`le_audio_cis_headset.c` - One of these ``cis`` modules is used by default. * :file:`le_audio_bis_gateway.c` or :file:`le_audio_bis_headset.c` - One of these ``bis`` modules is selected automatically when you :ref:`switch to the BIS configuration `. Only one of these files is used at compile time. Each of these files handles the Bluetooth connection and Bluetooth events and funnels the data to the relevant audio modules. * Application-specific custom modules: * Stream Control - This module implements a simple state machine for the application (``STREAMING`` or ``PAUSED``). It also handles events from Bluetooth LE and buttons, receives audio from the host, and forwards the audio data to the next module. * FIFO buffers * Synchronization module (part of `I2S-based firmware for gateway and headsets`_) - See `Synchronization module overview`_ for more information. Since the application architecture is uniform and the firmware code is shared, the set of audio modules in use depends on the chosen stream mode (BIS or CIS), the chosen audio inputs and outputs (USB or analog jack), and if the gateway or the headset configuration is selected. .. note:: In the current version of the application, the bootloader is disabled by default. Device Firmware Update (DFU) can only be enabled when :ref:`nrf53_audio_app_building_script`. See :ref:`nrf53_audio_app_configuration_configure_fota` for details. .. _nrf53_audio_app_overview_architecture_usb: USB-based firmware for gateway ------------------------------ The following figure shows an overview of the modules currently included in the firmware that uses USB: .. figure:: /images/octave_application_structure_gateway.svg :alt: nRF5340 Audio modules on the gateway using USB nRF5340 Audio modules on the gateway using USB In this firmware design, no synchronization module is used after decoding the incoming frames or before encoding the outgoing ones. The Bluetooth LE RX FIFO is mainly used to make decoding run in a separate thread. .. _nrf53_audio_app_overview_architecture_i2s: I2S-based firmware for gateway and headsets ------------------------------------------- The following figure shows an overview of the modules currently included in the firmware that uses I2S: .. figure:: /images/octave_application_structure.svg :alt: nRF5340 Audio modules on the gateway and the headsets using I2S nRF5340 Audio modules on the gateway and the headsets using I2S The Bluetooth LE RX FIFO is mainly used to make :file:`audio_datapath.c` (synchronization module) run in a separate thread. After encoding the audio data received from I2S, the frames are sent by the encoder thread using a function located in :file:`streamctrl.c`. .. _nrf53_audio_app_overview_architecture_sync_module: Synchronization module overview ------------------------------- The synchronization module (:file:`audio_datapath.c`) handles audio synchronization. To synchronize the audio, it executes the following types of adjustments: * Presentation compensation * Drift compensation The presentation compensation makes all the headsets play audio at the same time, even if the packets containing the audio frames are not received at the same time on the different headsets. In practice, it moves the audio data blocks in the FIFO forward or backward a few blocks, adding blocks of *silence* when needed. The drift compensation adjusts the frequency of the audio clock to adjust the speed at which the audio is played. This is required in the CIS mode, where the gateway and headsets must keep the audio playback synchronized to provide True Wireless Stereo (TWS) audio playback. As such, it provides both larger adjustments at the start and then continuous small adjustments to the audio synchronization. This compensation method counters any drift caused by the differences in the frequencies of the quartz crystal oscillators used in the development kits. Development kits use quartz crystal oscillators to generate a stable clock frequency. However, the frequency of these crystals always slightly differs. The drift compensation makes the inter-IC sound (I2S) interface on the headsets run as fast as the Bluetooth packets reception. This prevents I2S overruns or underruns, both in the CIS mode and the BIS mode. See the following figure for an overview of the synchronization module. .. figure:: /images/octave_application_structure_sync_module.svg :alt: nRF5340 Audio synchronization module overview nRF5340 Audio synchronization module overview Both synchronization methods use the SDU reference timestamps (:c:type:`sdu_ref`) as the reference variable. If the device is a gateway that is :ref:`using I2S as audio source ` and the stream is unidirectional (gateway to headsets), :c:type:`sdu_ref` is continuously being extracted from the LE Audio Controller Subsystem for nRF53 on the gateway. The extraction happens inside the :file:`le_audio_cis_gateway.c` and :file:`le_audio_bis_gateway.c` files' send function. The :c:type:`sdu_ref` values are then sent to the gateway's synchronization module, and used to do drift compensation. .. note:: Inside the synchronization module (:file:`audio_datapath.c`), all time-related variables end with ``_us`` (for microseconds). This means that :c:type:`sdu_ref` becomes :c:type:`sdu_ref_us` inside the module. As the nRF5340 is a dual-core SoC, and both cores need the same concept of time, each core runs a free-running timer in an infinite loop. These two timers are reset at the same time, and they run from the same clock source. This means that they should always show the same values for the same points in time. The network core of the nRF5340 running the LE controller for nRF53 uses its timer to generate the :c:type:`sdu_ref` timestamp for every audio packet received. The application core running the nRF5340 Audio application uses its timer to generate :c:type:`cur_time` and :c:type:`frame_start_ts`. After the decoding takes place, the audio data is divided into smaller blocks and added to a FIFO. These blocks are then continuously being fed to I2S, block by block. See the following figure for the details of the compensation methods of the synchronization module. .. figure:: /images/octave_application_sync_module_states.svg :alt: nRF5340 Audio's state machine for compensation mechanisms nRF5340 Audio's state machine for compensation mechanisms The following external factors can affect the presentation compensation: * The drift compensation must be synchronized to the locked state (:c:enumerator:`DRIFT_STATE_LOCKED`) before the presentation compensation can start. This drift compensation adjusts the frequency of the audio clock, indicating that the audio is being played at the right speed. When the drift compensation is not in the locked state, the presentation compensation does not leave the init state (:c:enumerator:`PRES_STATE_INIT`). Also, if the drift compensation loses synchronization, moving out of :c:enumerator:`DRIFT_STATE_LOCKED`, the presentation compensation moves back to :c:enumerator:`PRES_STATE_INIT`. * When audio is being played, it is expected that a new audio frame is received in each ISO connection interval. If this does not occur, the headset might have lost its connection with the gateway. When the connection is restored, the application receives a :c:type:`sdu_ref` not consecutive with the previously received :c:type:`sdu_ref`. Then the presentation compensation is put into :c:enumerator:`PRES_STATE_WAIT` to ensure that the audio is still in sync. .. note:: When both the drift and presentation compensation are in state *locked* (:c:enumerator:`DRIFT_STATE_LOCKED` and :c:enumerator:`PRES_STATE_LOCKED`), **LED2** lights up. Synchronization module flow +++++++++++++++++++++++++++ The received audio data in the I2S-based firmware devices follows the following path: 1. The LE Audio Controller Subsystem for nRF53 running on the network core receives the compressed audio data. #. The controller subsystem sends the audio data to the Zephyr Bluetooth LE host similarly to the :ref:`zephyr:bluetooth-hci-rpmsg-sample` sample. #. The host sends the data to the stream control module (:file:`streamctrl.c`). #. The data is sent to a FIFO buffer. #. The data is sent from the FIFO buffer to the :file:`audio_datapath.c` synchronization module. The :file:`audio_datapath.c` module performs the audio synchronization based on the SDU reference timestamps. Each package sent from the gateway gets a unique SDU reference timestamp. These timestamps are generated on the headset controllers (in the network core). This enables the creation of True Wireless Stereo (TWS) earbuds where the audio is synchronized in the CIS mode. It does also keep the speed of the inter-IC sound (I2S) interface synchronized with the sending and receiving speed of Bluetooth packets. #. The :file:`audio_datapath.c` module sends the compressed audio data to the LC3 audio decoder for decoding. #. The audio decoder decodes the data and sends the uncompressed audio data (PCM) back to the :file:`audio_datapath.c` module. #. The :file:`audio_datapath.c` module continuously feeds the uncompressed audio data to the hardware codec. #. The hardware codec receives the uncompressed audio data over the inter-IC sound (I2S) interface and performs the digital-to-analog (DAC) conversion to an analog audio signal. .. _nrf53_audio_app_requirements: Requirements ************ The nRF5340 Audio application is designed to be used only with the following hardware: +-----------------------------------------------------+----------------------------------+--------------------------+-------------------------------------+ | Hardware platforms | PCA | Board name | Build target | +=====================================================+==================================+==========================+=====================================+ | `nRF5340 Audio DK `_ | PCA10121 revision 1.0.0 or above | nrf5340_audio_dk_nrf5340 | ``nrf5340_audio_dk_nrf5340_cpuapp`` | +-----------------------------------------------------+----------------------------------+--------------------------+-------------------------------------+ .. note:: The application supports PCA10121 revisions 1.0.0 or above. The application is also compatible with the following pre-launch revisions: * Revisions 0.8.0 and above. You need at least two nRF5340 Audio development kits (one with the gateway firmware and one with headset firmware) to test the application. For CIS with TWS in mind, three kits are required. .. _nrf53_audio_app_requirements_codec: Software codec requirements =========================== The nRF5340 Audio application only supports the :ref:`LC3 software codec `, developed specifically for use with LE Audio. .. _nrf53_audio_app_dk: .. _nrf53_audio_app_dk_features: nRF5340 Audio development kit ============================= The nRF5340 Audio development kit is a hardware development platform that demonstrates the nRF5340 Audio application. Read the `nRF5340 Audio DK Hardware`_ documentation on Nordic Semiconductor Infocenter for more information about this development kit. .. _nrf53_audio_app_configuration_files: nRF5340 Audio configuration files ================================= The nRF5340 Audio application uses :file:`Kconfig.defaults` files to change configuration defaults automatically, based on the different application versions and device types. Only one of the following :file:`.conf` files is included when building: * :file:`prj.conf` is the default configuration file and it implements the debug application version. * :file:`prj_release.conf` is the optional configuration file and it implements the release application version. No debug features are enabled in the release application version. When building using the command line, you must explicitly specify if :file:`prj_release.conf` is going to be included instead of :file:`prj.conf`. See :ref:`nrf53_audio_app_building` for details. Requirements for FOTA ===================== To test Firmware Over-The-Air (FOTA), you need an Android or iOS device with the `nRF Connect Device Manager`_ app installed. If you want to do FOTA upgrades for the application core and the network core at the same time, you need an external flash shield. See :ref:`nrf53_audio_app_configuration_configure_fota` for more details. .. _nrf53_audio_app_ui: User interface ************** The application implements a simple user interface based on the available PCB elements. You can control the application using predefined switches and buttons while the LEDs display information. .. _nrf53_audio_app_ui_switches: Switches ======== The application uses the following switches on the supported development kit: +-------------------+-------------------------------------------------------------------------------------+ | Switch | Function | +===================+=====================================================================================+ | **POWER** | Turns the development kit on or off. | +-------------------+-------------------------------------------------------------------------------------+ | **DEBUG ENABLE** | Turns on or off power for debug features. | | | This switch is used for accurate power and current measurements. | +-------------------+-------------------------------------------------------------------------------------+ .. _nrf53_audio_app_ui_buttons: Buttons ======= The application uses the following buttons on the supported development kit: +---------------+-----------------------------------------------------------------------------------------------------------+ | Button | Function | +===============+===========================================================================================================+ | **VOL-** | Depending on the moment it is pressed: | | | | | | * Long-pressed during startup: Changes the headset to the left channel one. | | | * Pressed on the headset or the CIS gateway during playback: Turns the playback volume down (and unmutes).| +---------------+-----------------------------------------------------------------------------------------------------------+ | **VOL+** | Depending on the moment it is pressed: | | | | | | * Long-pressed during startup: Changes the headset to the right channel one. | | | * Pressed on the headset or the CIS gateway during playback: Turns the playback volume up (and unmutes). | +---------------+-----------------------------------------------------------------------------------------------------------+ | **PLAY/PAUSE**| Starts or pauses the playback. | +---------------+-----------------------------------------------------------------------------------------------------------+ | **BTN 4** | Depending on the moment it is pressed: | | | | | | * Long-pressed during startup: Turns on the DFU mode, if | | | the device is :ref:`configured for it`. | | | * Pressed on the gateway during playback: Sends a test tone generated on the device. | | | Use this tone to check the synchronization of headsets. | | | * Pressed on the gateway during playback multiple times: Changes the tone frequency. | | | The available values are 1000 Hz, 2000 Hz, and 4000 Hz. | | | * Pressed on a BIS headset during playback: Change audio stream, if more than one is | | | available. | +---------------+-----------------------------------------------------------------------------------------------------------+ | **BTN 5** | Depending on the moment it is pressed: | | | | | | * Long-pressed during startup: Clears the previously stored bonding information. | | | * Pressed during playback: Mutes the playback volume. | | | * Pressed on a BIS headset during playback: Change the gateway, if more than one is | | | available. | +---------------+-----------------------------------------------------------------------------------------------------------+ | **RESET** | Resets the device to the originally programmed settings. | | | This reverts any changes made during testing, for example the channel switches with **VOL** buttons. | +---------------+-----------------------------------------------------------------------------------------------------------+ .. _nrf53_audio_app_ui_leds: LEDs ==== To indicate the tasks performed, the application uses the LED behavior described in the following table: +--------------------------+-----------------------------------------------------------------------------------------------------+ | LED |Indication | +==========================+=====================================================================================================+ | **LED1** | Off - No Bluetooth connection. | | +-----------------------------------------------------------------------------------------------------+ | | Blinking blue - Depending on the device and the mode: | | | | | | * Headset: Kits have started streaming audio (BIS and CIS modes). | | | * Gateway: Kit has connected to a headset (CIS mode) or has started broadcasting audio (BIS mode). | | +-----------------------------------------------------------------------------------------------------+ | | Solid blue - Headset, depending on the mode: | | | Kits have connected to the gateway (CIS mode) or found a broadcasting stream (BIS mode). | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **LED2** | Off - Sync not achieved. | | +-----------------------------------------------------------------------------------------------------+ | | Solid green - Sync achieved (both drift and presentation compensation are in the ``LOCKED`` state). | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **LED3** | Blinking green - The nRF5340 Audio DK application core is running. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **CODEC** | Off - No configuration loaded to the onboard hardware codec. | | +-----------------------------------------------------------------------------------------------------+ | | Solid green - Hardware codec configuration loaded. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **RGB1** | Solid green - The device is programmed as the gateway. | | (bottom side LEDs around +-----------------------------------------------------------------------------------------------------+ | the center opening) | Solid blue - The device is programmed as the left headset. | | +-----------------------------------------------------------------------------------------------------+ | | Solid magenta - The device is programmed as the right headset. | | +-----------------------------------------------------------------------------------------------------+ | | Solid yellow - The device is programmed with factory firmware. | | | It must be re-programmed as gateway or headset. | | +-----------------------------------------------------------------------------------------------------+ | | Solid red (debug mode) - Fault in the application core has occurred. | | | See UART log for details and use the **RESET** button to reset the device. | | | In the release mode, the device resets automatically with no indication on LED or UART. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **RGB 2** | Controlled by the Bluetooth LE Controller on the network core. | | +-----------------------------------------------------------------------------------------------------+ | | Blinking green - Ongoing CPU activity. | | +-----------------------------------------------------------------------------------------------------+ | | Solid red - Error. | | +-----------------------------------------------------------------------------------------------------+ | | Solid white (all colors on) - The **RGB 2** LED is not initialized by the Bluetooth LE Controller. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **ERR** | PMIC error or a charging error (or both). | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **CHG** | Off - Charge completed or no battery connected. | | +-----------------------------------------------------------------------------------------------------+ | | Solid yellow - Charging in progress. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **OB/EXT** | Off - No 3.3 V power available. | | +-----------------------------------------------------------------------------------------------------+ | | Solid green - On-board hardware codec selected. | | +-----------------------------------------------------------------------------------------------------+ | | Solid yellow - External hardware codec selected. | | | This LED turns solid yellow also when the devices are reset, for the time then pins are floating. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **FTDI SPI** | Off - No data is written to the hardware codec using SPI. | | +-----------------------------------------------------------------------------------------------------+ | | Yellow - The same SPI is used for both the hardware codec and the SD card. | | | When this LED is yellow, the shared SPI is used by the FTDI to write data to the hardware codec. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **IFMCU** | Off - No PC connection available. | | (bottom side) +-----------------------------------------------------------------------------------------------------+ | | Solid green - Connected to PC. | | +-----------------------------------------------------------------------------------------------------+ | | Rapid green flash - USB enumeration failed. | +--------------------------+-----------------------------------------------------------------------------------------------------+ | **HUB** | Off - No PC connection available. | | (bottom side) +-----------------------------------------------------------------------------------------------------+ | | Green - Standard USB hub operation. | +--------------------------+-----------------------------------------------------------------------------------------------------+ .. _nrf53_audio_app_configuration: Configuration ************* |config| .. _nrf53_audio_app_configuration_select_bis: Selecting the BIS mode ====================== The CIS mode is the default operating mode for the application. You can switch to the BIS mode by adding the :kconfig:option:`CONFIG_TRANSPORT_BIS` Kconfig option set to ``y`` to the :file:`prj.conf` file for the debug version and the :file:`prj_release.conf` file for the release version. Enabling the BIS mode with two gateways --------------------------------------- In addition to the standard BIS mode with one gateway, you can also add a second gateway device that the BIS headsets can receive audio stream from. To configure the second gateway, add both the :kconfig:option:`CONFIG_TRANSPORT_BIS` and the :kconfig:option:`CONFIG_BT_AUDIO_USE_BROADCAST_NAME_ALT` Kconfig options set to ``y`` to the :file:`prj.conf` file for the debug version and to the :file:`prj_release.conf` file for the release version. You can provide an alternative name to the second gateway using the :kconfig:option:`CONFIG_BT_AUDIO_BROADCAST_NAME_ALT` or use the default alternative name. You build each BIS gateway separately using the normal procedures from :ref:`nrf53_audio_app_building`. After building the first gateway, configure the required Kconfig options for the second gateway and build the second gateway firmware. Remember to program the two firmware versions to two separate gateway devices. .. _nrf53_audio_app_configuration_select_bidirectional: Selecting the CIS bidirectional communication ============================================= The CIS unidirectional mode is the default operating mode for the application. You can switch to the bidirectional mode by adding the :kconfig:option:`CONFIG_STREAM_BIDIRECTIONAL` Kconfig option set to ``y`` to the :file:`prj.conf` file (for the debug version) or to the :file:`prj_release.conf` file (for the release version). .. _nrf53_audio_app_configuration_enable_walkie_talkie: Enabling the walkie-talkie demo ------------------------------- The walkie-talkie demo uses one or two bidirectional streams from the gateway to one or two headsets. The PDM microphone is used as input on both the gateway and headset device. You can switch to using the walkie-talkie by adding the :kconfig:option:`CONFIG_WALKIE_TALKIE_DEMO` Kconfig option set to ``y`` to the :file:`prj.conf` file (for the debug version) or to the :file:`prj_release.conf` file (for the release version). .. _nrf53_audio_app_configuration_select_i2s: Selecting the I2S serial ======================== In the default configuration, the gateway application uses the USB serial port as the audio source. The :ref:`nrf53_audio_app_building` and :ref:`nrf53_audio_app_testing` steps also refer to using the USB serial connection. You can switch to using the I2S serial connection by adding the ``CONFIG_AUDIO_SOURCE_I2S`` Kconfig option set to ``y`` to the :file:`prj.conf` file for the debug version and the :file:`prj_release.conf` file for the release version. When testing the application, an additional audio jack cable is required to use I2S. Use this cable to connect the audio source (PC) to the analog **LINE IN** on the development kit. .. _nrf53_audio_app_configuration_configure_fota: Configuring FOTA upgrades ========================= .. caution:: Firmware based on the |NCS| versions earlier than v2.1.0 does not support DFU. FOTA is not available for those versions. You can test performing separate application and network core upgrades, but for production, both cores must be updated at the same time. When updates take place in the inter-core communication module (HCI RPMsg), communication between the cores will break if they are not updated together. You can configure Firmware Over-The-Air (FOTA) upgrades to replace the applications on both the application core and the network core. The nRF5340 Audio application supports the following types of DFU flash memory layouts: * Internal flash memory layout - which supports only single-image DFU. * External flash memory layout - which supports :ref:`multi-image DFU `. The LE Audio Controller Subsystem for nRF53 supports both the normal and minimal sizes of the bootloader. The minimal size is specified using the :kconfig:option:`CONFIG_NETBOOT_MIN_PARTITION_SIZE`. Hardware requirements for external flash memory DFU --------------------------------------------------- To enable the external flash DFU, you need an additional flash memory shield. See `Requirements for external flash memory DFU`_ in the nRF5340 Audio DK Hardware documentation in Infocenter for more information. Enabling FOTA upgrades ---------------------- The FOTA upgrades are only available when :ref:`nrf53_audio_app_building_script`. With the appropriate parameters provided, the :file:`buildprog.py` Python script will add overlay files for the given DFU type. To enable the desired FOTA functions: * To define flash memory layout, include the ``-m internal`` parameter for the internal layout or the ``-m external`` parameter for the external layout. * To use the minimal size network core bootloader, add the ``-M`` parameter. For the full list of parameters and examples, see the :ref:`nrf53_audio_app_building_script_running` section. FOTA build files ---------------- The generated FOTA build files use the following naming patterns: * For multi-image DFU, the file is called ``dfu_application.zip``. This file updates two cores with one single file. * For single-image DFU, the bin file for the application core is called ``app_update.bin``. The bin file for the network core is called ``net_core_app_update.bin``. In this scenario, the cores are updated one by one with two separate files in two actions. See :ref:`app_build_output_files` for more information about the image files. .. note:: |net_core_hex_note| Entering the DFU mode --------------------- The |NCS| uses :ref:`SMP server and mcumgr ` as the DFU backend. Unlike the CIS and BIS modes for gateway and headsets, the DFU mode is advertising using the SMP server service. For this reason, to enter the DFU mode, you must long press **BTN 4** during each device startup to have the nRF5340 Audio DK enter the DFU mode. To identify the devices before the DFU takes place, the DFU mode advertising names mention the device type directly. The names follow the pattern in which the device *ROLE* is inserted before the ``_DFU`` suffix. For example: * Gateway: NRF5340_AUDIO_GW_DFU * Left Headset: NRF5340_AUDIO_HL_DFU * Right Headset: NRF5340_AUDIO_HR_DFU The first part of these names is based on :kconfig:option:`CONFIG_BT_DEVICE_NAME`. .. _nrf53_audio_app_building: Building and running ******************** This sample can be found under :file:`applications/nrf5340_audio` in the nRF Connect SDK folder structure. .. note:: Building and programming the nRF5340 Audio application is different from the :ref:`standard procedure ` of building and programming for the nRF5340 DK. This is because the nRF5340 Audio application only builds and programs the files for the application core. |net_core_hex_note| You can build and program the application in one of the following ways: * :ref:`nrf53_audio_app_building_script`. This is the suggested method. Using this method allows you to build and program multiple development kits at the same time. * :ref:`nrf53_audio_app_building_standard`. Using this method requires building and programming each development kit separately. .. note:: You might want to check the :ref:`nRF5340 Audio application known issues ` before building and programming the application. Testing out of the box ====================== Each development kit comes preprogrammed with basic firmware that indicates if the kit is functional. Before building the application, you can verify if the kit is working by completing the following steps: 1. Plug the device into the USB port. #. Turn on the development kit using the On/Off switch. #. Observe **RGB1** (bottom side LEDs around the center opening that illuminate the Nordic Semiconductor logo) turn solid yellow, **OB/EXT** turn solid green, and **LED3** start blinking green. You can now program the development kits with either gateway or headset firmware before they can be used. .. _nrf53_audio_app_adding_FEM_support: Adding FEM support ================== You can add support for the nRF21540 front-end module (FEM) to this application by using one of the following options, depending on how you decide to build the application: * If you opt for :ref:`nrf53_audio_app_building_script`, add the ``--nrf21540`` to the script's building command. * If you opt for :ref:`nrf53_audio_app_building_standard`, add the ``-DSHIELD=nrf21540_ek_fwd`` to the ``west build`` command. For example: .. code-block:: console west build -b nrf5340_audio_dk_nrf5340_cpuapp --pristine -- -DCONFIG_AUDIO_DEV=1 -DSHIELD=nrf21540_ek_fwd -DCONF_FILE=prj_release.conf You can use the :kconfig:option:`CONFIG_NRF_21540_MAIN_TX_POWER` and :kconfig:option:`CONFIG_NRF_21540_PRI_ADV_TX_POWER` to set the TX power output. See :ref:`ug_radio_fem` for more information about FEM in the |NCS|. .. _nrf53_audio_app_building_script: Building and programming using script ===================================== The suggested method for building the application and programming it to the development kit is running the :file:`buildprog.py` Python script, which is located in the :file:`applications/nrf5340_audio/tools/buildprog` directory. The script automates the process of selecting :ref:`configuration files ` and building different versions of the application. This eases the process of building and programming images for multiple development kits. Preparing the JSON file ----------------------- The script depends on the settings defined in the :file:`nrf5340_audio_dk_devices.json` file. Before using the script, make sure to update this file with the following information for each development kit you want to use: * ``nrf5340_audio_dk_snr`` -- This field lists the SEGGER serial number. You can check this number on the sticker on the nRF5340 Audio development kit. Alternatively, connect the development kit to your PC and run ``nrfjprog -i`` in a command window to print the SEGGER serial number of the kit. * ``nrf5340_audio_dk_dev`` -- This field assigns the specific nRF5340 Audio development kit to be a headset or a gateway. * ``channel`` -- This field is valid only for headsets operating in the CIS mode. It sets the channels on which the headset is meant to work. When no channel is set, the headset is programmed as a left channel one. .. _nrf53_audio_app_building_script_running: Running the script ------------------ After editing the :file:`nrf5340_audio_dk_devices.json` file, run :file:`buildprog.py` to build the firmware for the development kits. The building command for running the script requires providing the following parameters, in line with :ref:`nrf53_audio_app_configuration_files`: * Core type (``-c`` parameter): ``app``, ``net``, or ``both`` * Application version (``-b`` parameter): either ``release`` or ``debug`` * Device type (``-d`` parameter): ``headset``, ``gateway``, or ``both`` * DFU type (``-m`` parameter): ``internal``, ``external`` * Network core bootloader minimal size (``-M``) See the following examples of the parameter usage with the command run from the :file:`buildprog` directory: * Example 1: The following command builds the application using the script for the application core with the ``debug`` application version for both the headset and the gateway: .. code-block:: console python buildprog.py -c app -b debug -d both * Example 2: The following command builds the application using the script for both the application and the network core (``both``). As in *example 1*, it builds with the ``debug`` application version, but with the DFU internal flash memory layout enabled and using the minimal size of the network core bootloader: .. code-block:: console python buildprog.py -c both -b debug -d both -m internal -M If you run this command with the ``external`` DFU type parameter instead of ``internal``, the external flash memory layout will be enabled. The command can be run from any location, as long as the correct path to :file:`buildprog.py` is given. The build files are saved in the :file:`applications/nrf5340_audio/build` directory. The script creates a directory for each application version and device type combination. For example, when running the command above, the script creates the :file:`dev_gateway/build_debug` and :file:`dev_headset/build_debug` directories. Programming with the script The development kits are programmed according to the serial numbers set in the JSON file. Make sure to connect the development kits to your PC using USB and turn them on using the **POWER** switch before you run the command. The following parameters are available for programming: * Programming (``-p`` parameter) -- If you run the building script with this parameter, you can program one or both of the cores after building the files. * Sequential programming (``-s`` parameter) -- If you are using Windows Subsystem for Linux (WSL) and encounter problems while programming, include this parameter alongside other parameters to program sequentially. The command for programming can look as follows: .. code-block:: console python buildprog.py -c both -b debug -d both -p This command builds the application with the ``debug`` application version for both the headset and the gateway and programs the application core. Given the ``-c both`` parameter, it also takes the precompiled Bluetooth Low Energy Controller binary from the :file:`applications/nrf5340_audio/bin` directory and programs it to the network core of both the gateway and the headset. .. note:: If the programming command fails because of :ref:`readback_protection_error`, run :file:`buildprog.py` with the ``--recover-on-fail`` or ``-f`` parameter to recover and re-program automatically when programming fails. For example, using the programming command example above: .. code-block:: console python buildprog.py -c both -b debug -d both -p --recover-on-fail If you want to program firmware that has DFU enabled, you must include the DFU parameters in the command. The command for programming with DFU enabled can look as follows: .. code-block:: console python buildprog.py -c both -b debug -d both -m internal -M -p Getting help Run ``python buildprog.py -h`` for information about all available script parameters. Configuration table overview When running the script command, a table similar to the following one is displayed to provide an overview of the selected options and parameter values: .. code-block:: console +------------+----------+---------+--------------+---------------------+---------------------+ | snr | snr conn | device | only reboot | core app programmed | core net programmed | +------------+----------+---------+--------------+---------------------+---------------------+ | 1010101010 | True | headset | Not selected | Selected TBD | Not selected | | 2020202020 | True | gateway | Not selected | Selected TBD | Not selected | | 3030303030 | True | headset | Not selected | Selected TBD | Not selected | +------------+----------+---------+--------------+---------------------+---------------------+ See the following table for the meaning of each column and the list of possible values: +-----------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------------------+ | Column | Indication | Possible values | +=======================+=====================================================================================================+=================================================+ | ``snr`` | Serial number of the device, as provided in the :file:`nrf5340_audio_dk_devices.json` file. | Serial number. | +-----------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------------------+ | ``snr conn`` | Whether the device with the provided serial number is connected to the PC with a serial connection. | ``True`` - Connected. | | | +-------------------------------------------------+ | | | ``False`` - Not connected. | +-----------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------------------+ | ``device`` | Device type, as provided in the :file:`nrf5340_audio_dk_devices.json` file. | ``headset`` - Headset. | | | +-------------------------------------------------+ | | | ``gateway`` - Gateway. | +-----------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------------------+ | ``only reboot`` | Whether the device is to be only reset and not programmed. | ``Not selected`` - No reset. | | | This depends on the ``-r`` parameter in the command, which overrides other parameters. +-------------------------------------------------+ | | | ``Selected TBD`` - Only reset requested. | | | +-------------------------------------------------+ | | | ``Done`` - Reset done. | | | +-------------------------------------------------+ | | | ``Failed`` - Reset failed. | +-----------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------------------+ |``core app programmed``| Whether the application core is to be programmed. | ``Not selected`` - Core will not be programmed. | | | This depends on the value provided to the ``-c`` parameter (see above). +-------------------------------------------------+ | | | ``Selected TBD`` - Programming requested. | | | +-------------------------------------------------+ | | | ``Done`` - Programming done. | | | +-------------------------------------------------+ | | | ``Failed`` - Programming failed. | +-----------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------------------+ |``core net programmed``| Whether the network core is to be programmed. | ``Not selected`` - Core will not be programmed. | | | This depends on the value provided to the ``-c`` parameter (see above). +-------------------------------------------------+ | | | ``Selected TBD`` - Programming requested. | | | +-------------------------------------------------+ | | | ``Done`` - Programming done. | | | +-------------------------------------------------+ | | | ``Failed`` - Programming failed. | +-----------------------+-----------------------------------------------------------------------------------------------------+-------------------------------------------------+ .. _nrf53_audio_app_building_standard: Building and programming using command line =========================================== You can also build the nRF5340 Audio application using the standard |NCS| :ref:`build steps ` for the command line. .. note:: Using this method requires you to build and program each development kit one at a time before moving to the next configuration, which can be time-consuming. :ref:`nrf53_audio_app_building_script` is recommended. Building the application ------------------------ Complete the following steps to build the application: 1. Choose the combination of build flags: a. Choose the device type by using one of the following options: * For headset device: ``-DCONFIG_AUDIO_DEV=1`` * For gateway device: ``-DCONFIG_AUDIO_DEV=2`` #. Choose the application version by using one of the following options: * For the debug version: No build flag needed. * For the release version: ``-DCONF_FILE=prj_release.conf`` #. Build the application using the standard :ref:`build steps `. For example, if you want to build the firmware for the application core as a headset using the ``release`` application version, you can run the following command: .. code-block:: console west build -b nrf5340_audio_dk_nrf5340_cpuapp --pristine -- -DCONFIG_AUDIO_DEV=1 -DCONF_FILE=prj_release.conf Unlike when :ref:`nrf53_audio_app_building_script`, this command creates the build files directly in the :file:`build` directory. This means that you first need to program the headset development kits before you build and program gateway development kits. Alternatively, you can add the ``-d`` parameter to the ``west`` command to specify a custom build folder. This lets you build firmware for both headset and gateway before programming any development kits. Programming the application --------------------------- After building the files for the development kit you want to program, complete the following steps to program the application from the command line: 1. Plug the device into the USB port. .. note:: |usb_known_issues| #. Turn on the development kit using the On/Off switch. #. Open a command prompt. #. Run the following command to print the SEGGER serial number of your development kit: .. code-block:: console nrfjprog -i .. note:: Pay attention to which device is to be programmed with the gateway HEX file and which devices are to be programmed with the headset HEX file. #. Program the network core on the development kit by running the following command: .. code-block:: console nrfjprog --program bin/*.hex --chiperase --coprocessor CP_NETWORK -r |net_core_hex_note| #. Program the application core on the development kit with the respective HEX file from the :file:`build` directory by running the following command: .. code-block:: console nrfjprog --program build/zephyr/zephyr.hex --coprocessor CP_APPLICATION --chiperase -r In this command, :file:`build/zephyr/zephyr.hex` is the HEX binary file for the application core. If a custom build folder is specified, the path to this folder must be used instead of :file:`build/`. #. If any device is not programmed due to :ref:`readback_protection_error`, complete the following steps: a. Run the following commands to recover the device: .. code-block:: console nrfjprog --recover --coprocessor CP_NETWORK nrfjprog --recover #. Repeat steps 5 and 6 to program both cores again. #. When using the default CIS configuration, if you want to use two headset devices, you must also populate the UICR with the desired channel for each headset. Use the following commands, depending on which headset you want to populate: * Left headset: .. code-block:: console nrfjprog --memwr 0x00FF80F4 --val 0 * Right headset: .. code-block:: console nrfjprog --memwr 0x00FF80F4 --val 1 Select the correct board when prompted with the popup or add the ``--snr`` parameter followed by the SEGGER serial number of the correct board at the end of the ``nrfjprog`` command. .. _nrf53_audio_app_testing: Testing ======= After building and programming the application, you can test it for both the CIS and the BIS modes. The following testing scenarios assume you are using USB as the audio source on the gateway. This is the default setting. .. _nrf53_audio_app_testing_steps_cis: Testing the default CIS mode ---------------------------- Complete the following steps to test the unidirectional CIS mode for one gateway and two headset devices: 1. Make sure that the development kits are still plugged into the USB ports and are turned on. .. note:: |usb_known_issues| After programming, **RGB2** starts blinking green on every device to indicate the ongoing CPU activity on the network core. **LED3** starts blinking green on every device to indicate the ongoing CPU activity on the application core. #. Wait for the **LED1** on the gateway to start blinking blue. This happens shortly after programming the development kit and indicates that the gateway device is connected to at least one headset and ready to send data. #. Search the list of audio devices listed in the sound settings of your operating system for *nRF5340 USB Audio* (gateway) and select it as the output device. #. Connect headphones to the **HEADPHONE** audio jack on both headset devices. #. Start audio playback on your PC from any source. #. Wait for **LED1** to blink blue on both headsets. When they do, the audio stream has started on both headsets. .. note:: The audio outputs only to the left channel of the audio jack, even if the given headset is configured as the right headset. This is because of the mono hardware codec chip used on the development kits. If you want to play stereo sound using one development kit, you must connect an external hardware codec chip that supports stereo. #. Wait for **LED2** to light up solid green on the headsets to indicate that the audio synchronization is achieved. #. Press the **VOL+** button on one of the headsets. The playback volume increases for both headsets. #. Press the **VOL-** button on the gateway. The playback volume decreases for both headsets. #. Press the **PLAY/PAUSE** button on any one of the devices. The playback stops for both headsets and the streaming state for all devices is set to paused. #. Press the **RESET** button on the gateway. The gateway resets and the playback on the unpaused headset stops. After some time, the gateway establishes the connection with both headsets and resumes the playback on the unpaused headset. #. Press the **PLAY/PAUSE** button on any one of the devices. The playback resumes in both headsets. #. Press the **BTN 4** button on the gateway multiple times. For each button press, the audio stream playback is stopped and the gateway sends a test tone to both headsets. These tones can be used as audio cues to check the synchronization of the headsets. #. Hold down the **VOL+** button and press the **RESET** button on the left headset. After startup, this headset will be configured as the right channel headset. #. Hold down the **VOL-** button and press the **RESET** button on the left headset. After startup, this headset will go back to be configured as the left channel headset. You can also just press the **RESET** button to restore the original programmed settings. After the kits have paired for the first time, they are now bonded. This means the Long-Term Key (LTK) is stored on each side, and that the kits will only connect to each other unless the bonding information is cleared. To clear the bonding information, press and hold **BTN 5** during boot. When you finish testing, power off the nRF5340 Audio development kits by switching the power switch from On to Off. .. _nrf53_audio_app_testing_steps_bis: Testing the BIS mode -------------------- Testing the BIS mode is identical to `Testing the default CIS mode`_, except for the following differences: * You must :ref:`select the BIS mode manually ` before building the application. * You can play the audio stream with different audio settings on the receivers. For example, you can decrease or increase the volume separately for each receiver during playback. * When pressing the **PLAY/PAUSE** button on a headset, the streaming state only changes for that given headset. * Pressing the **PLAY/PAUSE** button on the gateway will respectively start or stop the stream for all headsets listening in. * Pressing the **BTN 4** button on a headset will change the active audio stream. The default configuration of the BIS mode supports two audio streams (left and right). * Pressing the **BTN 5** button on a headset will change the gateway source for the audio stream (after `Enabling the BIS mode with two gateways`_). If a second gateway is not present, the headset will not play audio. .. _nrf53_audio_app_testing_steps_cis_walkie_talkie: Testing the walkie-talkie demo ------------------------------ Testing the walkie-talkie demo is identical to `Testing the default CIS mode`_, except for the following differences: * You must enable the Kconfig option mentioned in `Enabling the walkie-talkie demo`_ before building the application. * Instead of controlling the playback, you can speak through the PDM microphones. The line is open all the time, no need to press any buttons to talk, but the volume control works as in `Testing the default CIS mode`_. .. _nrf53_audio_app_porting_guide: Testing FOTA upgrades --------------------- `nRF Connect Device Manager`_ can be used for testing FOTA upgrades. The procedure for upgrading the firmware is identical for both headset and gateway firmware. You can test upgrading the firmware on both cores at the same time on a headset device by completing the following steps: 1. Make sure you have :ref:`configured the application for FOTA `. #. Install `nRF Connect Device Manager`_ on your Android or iOS device. #. Connect an external flash shield to the headset. #. Make sure the headset runs a firmware that supports DFU using external flash memory. One way of doing this is to connect the headset to the USB port, turn it on, and then run this command: .. code-block:: console python buildprog.py -c both -b debug -d headset --pristine -m external -p .. note:: When using the FOTA related functionality in the :file:`buildprog.py` script on Linux, the ``python`` command must execute Python 3. #. Use the :file:`buildprog.py` script to create a zip file that contains new firmware for both cores: .. code-block:: console python buildprog.py -c both -b debug -d headset --pristine -m external #. Transfer the generated file to your Android or iOS device, depending on the DFU scenario. See the `FOTA build files`_ section for information about FOTA file name patterns. For transfer, you can use cloud services like Google Drive for Android or iCloud for iOS. #. Enter the DFU mode by pressing and holding down **RESET** and **BTN 4** at the same time, and then releasing **RESET** while continuing to hold down **BTN 4** for a couple more seconds. #. Open `nRF Connect Device Manager`_ and look for ``NRF5340_AUDIO_HL_DFU`` in the scanned devices window. The headset is left by default. #. Tap on :guilabel:`NRF5340_AUDIO_HL_DFU` and then on the downward arrow icon at the bottom of the screen. #. In the :guilabel:`Firmware Upgrade` section, tap :guilabel:`SELECT FILE`. #. Select the file you transferred to the device. #. Tap :guilabel:`START` and check :guilabel:`Confirm only` in the notification. #. Tap :guilabel:`START` again to start the DFU process. #. When the DFU has finished, verify that the new application core and network core firmware works properly. Adapting application for end products ************************************* This section describes the relevant configuration sources and lists the steps required for adapting the nRF5340 Audio application to end products. Board configuration sources =========================== The nRF5340 Audio application uses the following files as board configuration sources: * Devicetree Specification (DTS) files - These reflect the hardware configuration. See :ref:`zephyr:dt-guide` for more information about the DTS data structure. * Kconfig files - These reflect the hardware-related software configuration. See :ref:`kconfig_tips_and_tricks` for information about how to configure them. * Memory layout configuration files - These define the memory layout of the application. You can see the :file:`nrf/boards/arm/nrf5340_audio_dk_nrf5340` directory as an example of how these files are structured. For information about differences between DTS and Kconfig, see :ref:`zephyr:dt_vs_kconfig`. For detailed instructions for adding Zephyr support to a custom board, see Zephyr's :ref:`zephyr:board_porting_guide`. .. _nrf53_audio_app_porting_guide_app_configuration: Application configuration sources ================================= The application configuration source file defines a set of options used by the nRF5340 Audio application. This is a :file:`.conf` file that modifies the default Kconfig values defined in the Kconfig files. Only one :file:`.conf` file is included at a time. The :file:`prj.conf` file is the default configuration file and it implements the debug application version. For the release application version, you need to include the :file:`prj_release.conf` configuration file. In the release application version no debug features should be enabled. The nRF5340 Audio application also use several :file:`Kconfig.defaults` files to change configuration defaults automatically, based on the different application versions and device types. You need to edit :file:`prj.conf` and :file:`prj_release.conf` if you want to add new functionalities to your application, but editing these files when adding a new board is not required. .. _nrf53_audio_app_porting_guide_adding_board: Adding a new board ================== .. note:: The first three steps of the configuration procedure are identical to the steps described in Zephyr's :ref:`zephyr:board_porting_guide`. To use the nRF5340 Audio application with your custom board: 1. Define the board files for your custom board: a. Create a new directory in the :file:`nrf/boards/arm/` directory with the name of the new board. #. Copy the nRF5340 Audio board files from the :file:`nrf5340_audio_dk_nrf5340` directory located in the :file:`nrf/boards/arm/` folder to the newly created directory. #. Edit the DTS files to make sure they match the hardware configuration. Pay attention to the following elements: * Pins that are used. * Interrupt priority that might be different. #. Edit the board's Kconfig files to make sure they match the required system configuration. For example, disable the drivers that will not be used by your device. #. Build the application by selecting the name of the new board (for example, ``new_audio_board_name``) in your build system. For example, when building from the command line, add ``-b new_audio_board_name`` to your build command. FOTA for end products ===================== Do not use the default MCUboot key for end products. See :ref:`ug_fw_update` and :ref:`west-sign` for more information. To create your own app that supports DFU, you can use the `nRF Connect Device Manager`_ libraries for Android and iOS. Changing default values ======================= Given the requirements for the Coordinated Set Identification Service (CSIS), make sure to change the Set Identity Resolving Key (SIRK) value when adapting the application. Dependencies ************ .. note:: The following lists mention the most important dependencies. For the full list, check the application's Kconfig options. All dependencies are automatically included. The application uses the following |NCS| components: * :ref:`lib_contin_array` * :ref:`lib_pcm_mix` * :ref:`lib_tone` This application uses the following `nrfx`_ libraries: * :file:`nrfx_clock.h` * :file:`nrfx_gpiote.h` * :file:`nrfx_timer.h` * :file:`nrfx_dppi.h` * :file:`nrfx_i2s.h` * :file:`nrfx_ipc.h` * :file:`nrfx_nvmc.h` The application also depends on the following Zephyr libraries: * :ref:`zephyr:logging_api` * :ref:`zephyr:kernel_api` * :ref:`zephyr:api_peripherals`: * :ref:`zephyr:usb_api` * :ref:`zephyr:bluetooth_api`: * :file:`include/bluetooth/bluetooth.h` * :file:`include/bluetooth/gatt.h` * :file:`include/bluetooth/hci.h` * :file:`include/bluetooth/uuid.h` Application configuration options ********************************* .. options-from-kconfig:: :show-type: .. _nrf53_audio_app_dk_legal: Disclaimers for the nRF5340 Audio application ********************************************* This application and the LE Audio Controller Subsystem for nRF53 are marked as :ref:`experimental `. The DFU/FOTA functionality in this application is also marked as :ref:`experimental `. This LE Audio link controller is tested and works in configurations used by the present reference code (for example, 2 concurrent CIS, or BIS). No other configurations than the ones used in the reference application are tested nor documented in this release. .. |net_core_hex_note| replace:: The network core for both gateway and headsets is programmed with the precompiled Bluetooth Low Energy Controller binary file :file:`ble5-ctr-rpmsg_.hex`, where ** corresponds to the controller version, for example :file:`ble5-ctr-rpmsg_3216.hex`. This file includes the LE Audio Controller Subsystem for nRF53 and is provided in the :file:`applications/nrf5340_audio/bin` directory. If :ref:`DFU is enabled `, the subsystem's binary file will be generated in the :file:`build/zephyr/` directory and will be called :file:`net_core_app_signed.hex`. .. |usb_known_issues| replace:: Make sure to check the :ref:`nRF5340 Audio application known issues ` related to serial connection with the USB.