Building and running nRF5340 Audio applications

This nRF5340 Audio application source files can be found in their respective folders under applications/nrf5340_audio in the nRF Connect SDK folder structure.

You can build and program the applications in one of the following ways:

Building and programming using script. This is the suggested method. Using this method allows you to build and program multiple development kits at the same time.
Building and programming using command line. Using this method requires building and programming each development kit separately.

Important

Building and programming using the nRF Connect for VS Code extension is currently not supported.

Note

You might want to check the nRF5340 Audio application known issues before building and programming the applications.

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:

Plug the device into the USB port.
Turn on the development kit using the On/Off switch.
Observe RGB (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 kit.

Building and programming using script 

The suggested method for building each of the applications and programming it to the development kit is running the buildprog.py Python script, which is located in the applications/nrf5340_audio/tools/buildprog directory. The script automates the process of selecting configuration files and building different applications. 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 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 headset or gateway.
channel – This field is valid only for headsets. 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.

Running the script 

After editing the nrf5340_audio_dk_devices.json file, run buildprog.py to build the firmware for the development kits. The building command for running the script requires providing the following parameters:

Core type (-c parameter): app, net, or both
Application version (-b parameter): either release or debug
Device type (-d parameter): headset, gateway, or both

See the following examples of the parameter usage with the command run from the buildprog directory:

Example 1: The following command builds headset and gateway applications using the script for the application core with the debug application version:
```
python buildprog.py -c app -b debug -d both
```
Example 2: The following command builds headset and gateway applications using the script for both the application and the network core (both). It builds with the release application version, with the DFU external flash memory layout enabled, and using the minimal size of the network core bootloader:
```
python buildprog.py -c both -b release -d both -m external -M
```

The command can be run from any location, as long as the correct path to buildprog.py is given.

The build files are saved in the 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 dev_gateway/build_debug and 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 encounter problems while programming, include this parameter alongside other parameters to program sequentially.

The command for programming can look as follows:

python buildprog.py -c both -b debug -d both -p

This command builds the headset and the gateway applications with debug version of both the application core binary and the network core binary - and programs each to its respective core.

Note

If the programming command fails because of a readback protection error, run 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:

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:

python buildprog.py -c both -b release -d both -m external -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:

+------------+----------+---------+--------------+---------------------+---------------------+
| 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 `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.
`snr conn`		`False` - Not connected.
`device`	Device type, as provided in the `nrf5340_audio_dk_devices.json` file.	`headset` - Headset.
`device`		`gateway` - Gateway.
`only reboot`	Whether the device is to be only reset and not programmed. This depends on the `-r` parameter in the command, which overrides other parameters.	`Not selected` - No reset.
		`Selected TBD` - Only reset requested.
		`Done` - Reset done.
		`Failed` - Reset failed.
`core app programmed`	Whether the application core is to be programmed. This depends on the value provided to the `-c` parameter (see above).	`Not selected` - Core will not be programmed.
		`Selected TBD` - Programming requested.
		`Done` - Programming done.
		`Failed` - Programming failed.
`core net programmed`	Whether the network core is to be programmed. This depends on the value provided to the `-c` parameter (see above).	`Not selected` - Core will not be programmed.
		`Selected TBD` - Programming requested.
		`Done` - Programming done.
		`Failed` - Programming failed.

Building and programming using command line 

You can also build the nRF5340 Audio applications using the standard nRF Connect SDK build steps for the command line.

Application configuration files 

The application uses a prj.conf configuration file located in the sample root directory for the default configuration. It also provides additional files for different custom configurations. When you build the sample, you can select one of these configurations using the FILE_SUFFIX variable.

See Custom configurations and Providing CMake options for more information.

The application supports the following custom configurations:

Application custom configurations
Configuration	File name	FILE_SUFFIX	Description
Debug (default)	`prj.conf`	No suffix	Debug version of the application. Provides full logging capabilities and debug optimizations to ease development.
Release	`prj_release.conf`	`release`	Release version of the application. Disables logging capabilities and disables development features to create a smaller application binary.
FOTA DFU	`prj_fota.conf`	`fota`	Builds the debug version of the application with the features needed to perform DFU over Bluetooth LE, and includes bootloaders so that the applications on both the application core and network core can be updated. See Configuring and testing FOTA upgrades for nRF5340 Audio applications for more information.

Building the application 

Complete the following steps to build the application:

Choose the combination of build flags:
1. 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
2. Choose the application version by using one of the following options:
  - For the debug version: No build flag needed.
  - For the release version: -DFILE_SUFFIX=release
Build the application using the standard build steps for the command line. 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 from the applications/nrf5340_audio/ directory:
```
west build -b nrf5340_audio_dk/nrf5340/cpuapp --pristine -- -DCONFIG_AUDIO_DEV=1 -DFILE_SUFFIX=release
```
Unlike when Building and programming using script, this command creates the build files directly in the 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, follow the standard procedure for programming applications in the nRF Connect SDK.

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:
nrfjprog --memwr 0x00FF80F4 --val 0
Right headset:
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.

Note

Make sure to check the nRF5340 Audio application known issues related to serial connection with the USB.