nRF5 SDK for Mesh v3.1.0
Building the mesh stack and examples

The mesh library and example applications can be built with either SEGGER Embedded Studio or CMake. Before you start building, remember to set up the mesh development environment first. See Installing the toolchain for details.

Table of contents

Building with SEGGER Embedded Studio

SEGGER Embedded Studio (SES) provides a way of quickly getting the example code up and running with full debug capability.

First time setup

Before building the mesh examples with SEGGER Embedded Studio for the first time, you must complete a one-time setup of the SDK_ROOT macro in SEGGER Embedded Studio. This macro is used to find the nRF5 SDK files.

You can either:

To set the SDK_ROOT macro manually in SEGGER Embedded Studio:

  1. Go to Tools -> Options.
  2. Select Building.
  3. Under Build in the configuration list, edit Global macros to contain SDK_ROOT=<the path to nRF5 SDK instance>.
  4. Save the configuration.

You can verify the path by opening one of the source files under the nRF5 SDK file group. If the macro is set correctly, the file opens in the editor window. If not, an error message is displayed with information that the file cannot be found.

For more info on SEGGER Embedded Studio macros, see the SES Project macros page.

Building with SES

To build an example with SEGGER Embedded Studio:

  1. Open the desired project file located in the examples/ folder, for instance examples/light_switch/client/light_switch_client_nrf52832_xxAA_s132_6_1_0.emProject.
  2. Go to Build -> Build < name of the emProject file>, for instance Build light_switch_client_nrf52832_xxAA_s132_6.1.0.
  3. Wait for the compilation to finish.

You can now run the example using SEGGER Embedded Studio.

Building with CMake

CMake provides the possibility to build both for host (unit tests) and target.

CMake is "an extensible, open-source system that manages the build process in an operating system and in a compiler-independent manner" (as stated on the official CMake website).

In other words, CMake does not build from the source directly, but generates the native build tool files (for example, a set of Makefiles or a configuration). The choice of which build tool is to be targeted is controlled with the -G argument, for example: -G Ninja, -G "Unix Makefiles" and many more. CMake can generate IDE project files for IDEs such as Eclipse as well. However, this guide only targets Ninja and GNU Make.

  • All examples built by the CMake-generated build system do not include the SoftDevice as part of the generated HEX files. Therefore, the SoftDevice must already be present on the device before flashing the HEX file for the example mesh application.
  • There is a merge_<target> for each of the example targets that uses mergehex to generate a hexfile with the application and SoftDevice merged. Take special care with the order of programming when the application has bootloader support. Follow the Configuring DFU over Mesh in these cases. Example use:
     build $ ninja merge_light_switch_server_nrf52832_xxAA_s132_6.1.0
  • There is a flash_<target> for each of the example targets that runs an interactive programming tool. This requires the nRFx Command Line tools and Python 3 to be installed (see Installing the toolchain). Example use:
     build $ ninja flash_light_switch_server_nrf52832_xxAA_s132_6.1.0

The following three steps are mandatory when building with CMake:

Using CMake for building also comes with useful additional options.

Step 1: Generating build files

This section describes generating build files for the Ninja build tool.

On Debian/Linux, you may drop the -G Ninja argument as the default generator is for Unix Makefiles and use the make command instead of ninja.

Good practice is to create a build folder in the root directory for the mesh stack repository, where all artifacts generated by the Ninja build system are stored:

nrf5_sdk_for_mesh $ mkdir build
nrf5_sdk_for_mesh $ cd build

Before you can build with Ninja, you must generate the correct build files with CMake.

Calling cmake -G Ninja with no parameters will default to the nrf52832_xxAA platform with the s132_6.1.0 SoftDevice and gccarmemb toolchain:

build$ cmake -G Ninja ..
You can also use the cmake-gui -GNinja .. command to open the CMake graphical user interface when configuring the SDK. Press Configure and then Generate to generate the build files.


You can specify the required TOOLCHAIN and PLATFORM name to CMake. The build system will ensure a valid BOARD and SOFTDEVICE combination for each given platform.

build$ cmake -G Ninja -DTOOLCHAIN=<toolchain> -DPLATFORM=<platform> ..

Possible options for the toolchain and platform:

Example: To build mesh stack for nRF52 DK with GNU ARM Embedded toolchain, use:

build$ cmake -G Ninja -DTOOLCHAIN=gccarmemb -DPLATFORM=nrf52832_xxAA ..

You can also customize BOARD and SOFTDEVICE options with -D command line switches:

Step 2: Building the stack and examples

After the Ninja build files are generated, running ninja will build all the targets (examples and libraries).

If you have PC-Lint installed, the sources can be linted using the ninja lint command.

To see a list of available build targets, run the following command:

build $ ninja help

Example: To build a specific target from this list with the current platform nrf52832_xxAA and the s132_6.1.0 SoftDevice, run:

ninja light_switch_server_nrf52832_xxAA_s132_6.1.0

CMake generates Ninja build files in the folder in which CMake is run, so all targets must be built from that directory. In other words, in-directory building is not supported and running ninja in one of the example folders results in an error message generated by the Ninja build system.

Step 3: Generating SEGGER Embedded Studio project files

Warning: The generator will overwrite any existing projects. Back up existing projects before running the generator.

It is possible to generate SEGGER Embedded Studio project files using the CMake build system. With the option GENERATE_SES_PROJECTS enabled, CMake will generate a SES project based on the current settings.

Example: To generate a project for nrf52832_xxAA using the S132 v6.1.0 SoftDevice, run CMake in your build directory:

cmake -G Ninja -DGENERATE_SES_PROJECTS=ON -DPLATFORM=nrf52832_xxAA -DSOFTDEVICE=s132_6.1.0 ..

Additional CMake options

The following procedures can be useful when working with CMake:

Useful CMake command line options

CMake allows you to generate project files in release or debug configurations. To do so, use the -DCMAKE_BUILD_TYPE option:

build $ cmake -DCMAKE_BUILD_TYPE=Release ..      # Generates build files in release mode
build $ cmake -DCMAKE_BUILD_TYPE=Debug ..        # Generates build files in debug mode
build $ cmake -DCMAKE_BUILD_TYPE=MinSizeRel ..   # Generates build files optimized for size

The default build type is Debug if the CMake project is a Git repository (contains a .git directory). Otherwise, it is set to RelWithDebInfo.

Creating a new build target

To create a new build target:

  1. Copy one of the example folders, for example examples/beaconing to examples/my_app.
  2. Add the folder to the examples/CMakeLists.txt with the add_subfolder("my_app") command.
  3. Modify the target name in the first line of examples/my_app/CMakeLists.txt to set(target "my_app").
  4. Build your new target with the following command:
     build $ ninja my_app

Building documentation

Building documentation requires additional command line tools. See the list on Installing the toolchain page.

To build all documentation (API documentation and internal documentation), call the build system with the target doc.

build $ ninja doc

The Doxygen documentation is generated in <build folder>/doc/offline/html.

Building and running unit tests (host)

Building unit tests is optional and requires additional tools. See the table of required tools on Installing the toolchain page.

To build units tests:

  1. Enter the nrf5_sdk_for_mesh directory and make a new build directory, for example build_host:
     nrf5_sdk_for_mesh $ mkdir -p build_host && cd build_host
  2. Set the option BUILD_HOST to ON and CMAKE_BUILD_TYPE to Debug:

     build_host $ cmake -G Ninja -DBUILD_HOST=ON -DCMAKE_BUILD_TYPE=Debug ..
    • CMake is set up to look for CMock in the directory above the nrf5_sdk_for_mesh folder. If it is not located next to the mesh folder, you can specify its path by passing -DCMOCK_ROOT=<dir/cmock>.
    • If a different version of Unity is used than the one included as a submodule in CMock, you can specify its path by passing -DUNITY_ROOT=<dir/unity>.
    • All paths given to CMake must use forward slashes ('/') as directory separators.
  3. Build all the unit tests with ninja:
     build_host $ ninja

To run the tests, you can either:

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