nrf: Nordic Semiconductor nRF5340 and nRF52840 (nRF MDK)

This guide’s aim is to help you with using Contiki-NG for Nordic Semiconductor’s nRF5340 and nRF52840 SoCs (using nRF MDK).

This port supports the PCA10095 (nRF5340-DK), PCA10059 (nRF52840-DONGLE) and PCA10056 (nRF52840-DK) boards.

Port Features

The following features have been implemented:

  • Support for the 802.15.4 mode of the radio, including IPv6 using 6LoWPAN

  • Support for both TSCH and CSMA

  • No dependency on the nRF5 SDK

  • Contiki-NG system clock and rtimers

  • UART driver

  • Watchdog driver

  • RNG driver seeded from the hardware RNG

  • Temperature sensor driver

  • DK/Dongle LED and Button driver

Note that this port does not support BLE.

The port is organized as follows:

  • nRF CPU drivers are located in the arch/cpu/nrf folder.

  • The nrfx is located in the arch/cpu/nrf/lib/nrfx folder. This will be installed automatically as a git submodule.

  • nRF boards configuration are located in the arch/platform/nrf/<SoC>/<Board>/<Core (nRF5340 Exclusive)>/ folder.

    • SoC’s: nrf5340, nrf52840

    • Boards:

      • nrf5340: dk

      • nrf52840: dk, dongle

    • Cores:

      • nrf5340: application, network

Prerequisites and Setup

In order to compile for the nRF5340 and nRF52840 platforms you’ll need:

  • An ARM compatible toolchain

The toolchain used to build Contiki-NG is arm-gcc, also used by other arm-based Contiki-NG ports.

If you use the docker image or the vagrant image, this will be pre-installed for you. Otherwise, depending on your system, please follow the respective installation instructions (native Linux / native mac OS)

  • GNU make

  • nrfjprog for programming the nRF5340 DK, nRF52840 DK

nrfjprog is supplied as part of the nRF Command Line Tools and can be downloaded from the following link:

https://www.nordicsemi.com/Software-and-tools/Development-Tools/nRF-Command-Line-Tools

  • nrfutil for programming the nRF52840 Dongle

nrfutil is available on PyPy: https://pypi.org/project/nrfutil/

A typical way to install this would be using pip: pip3 install nrfutil

Getting Started

Once all tools are installed it is recommended to start by compiling and flashing examples/hello-world application. This allows to verify that toolchain setup is correct.

To compile the example, go to examples/hello-world and execute:

make TARGET=nrf

If the compilation is completed without errors flash the board:

make TARGET=nrf hello-world.upload

Examples

This target supports all the common IPv6 examples available under the examples/ folder.

Compilation Options

The Contiki-NG TARGET name for this port is nrf, so in order to compile an application you need to invoke GNU make as follows:

make TARGET=nrf

In addition to this port supports the following variables which can be set on the compilation command line:

  • NRF_UPLOAD_SN=<serial number>
    Allows to choose a particular DK by its serial number (printed on the label).
    This is useful if you have more than one DK connected to your PC and wish to flash a particular device using the .upload target.

  • BOARD={nrf5340/dk/application|nrf5340/dk/network|nrf52840/dk|nrf52840/dongle}
    Allows to specify if the which board and core (nrf5340 exclusive) is used. The default board is nrf5340/dk/application Dongle images are built with a bootloader-specific linker file and should be flashed using the .dfu-upload target.

  • NRF_NATIVE_USB=<0,1>
    Enables or disables the native USB support on boards that have USB support. This will automatically change the debug and the slip from UART to USB.

Compilation Targets

Invoking make solely with the TARGET variable set will build all applications in a given folder. A particular application can be built by invoking make with its name as a compilation target:

make TARGET=nrf hello-world

In order to flash the application binary to a single nRF5340 DK board in the application core use <application>.upload as make target, e.g.:

make TARGET=nrf hello-world.upload

In order to flash the application binary to all attached nRF5340 DK board in the application core use <application>.upload-all as make target, e.g.:

make TARGET=nrf hello-world.upload-all

In order to flash the application binary to a single nRF52840 Dongle use <application>.dfu-upload as make target, e.g.:

make TARGET=nrf BOARD=nrf52840/dongle hello-world.dfu-upload PORT=/dev/ttyACM0

Where PORT is the name of the USB CDC-ACM port that the dongle is on.
The bootloader can be activated by pressing the RESET button once, until the red LED begins to pulse.

Notes when using the nRF dongle:

  • The serial output from the dongle can be accessed by attaching a USB to Serial converter to the pins described on the back of the board.

  • If nrfutil returns an error such as LIBUSB_ERROR_ACCESS when attempting to perform a DFU trigger the following udev rules might be required:

## Set /dev/bus/usb/*/* as read-write for all users (0666) for Nordic Semiconductor devices
SUBSYSTEM=="usb", ATTRS{idVendor}=="1915", MODE="0666"

To remove all build results invoke:

make TARGET=nrf clean

nRF5340

The nRF5340 is a dual-core SoC with two ARM Cortex-M33 processors known as the application core and the network core. Only the network core has access to the 802.15.4 radio peripheral.

TrustZone Secure Radio

The IPC radio driver can optionally run in the ARM TrustZone secure world, providing a hardware-enforced security boundary for radio communication. In this mode, the normal world accesses the radio through Non-Secure Callable (NSC) entry points that validate all pointers via CMSE. This enables communication policies to be enforced in the secure world.

Building for TrustZone:

  1. Build the secure world and the network core radio service:

     make -C examples/platform-specific/nrf/trustzone/secure-world
 make -C examples/platform-specific/nrf/ipc-radio-service TARGET=nrf BOARD=nrf5340/dk/network

  2. Build the normal-world application:

     make -C examples/rpl-udp TARGET=nrf BOARD=nrf5340/dk/application \
      TRUSTZONE_SECURE_BUILD=0 \
      TRUSTZONE_SECURE_WORLD_PATH=../../examples/platform-specific/nrf/trustzone/secure-world \
      udp-server

    The tz_radio_driver is selected automatically in the normal-world build.

  3. Merge the secure and normal world hex files:

     srec_cat \
   examples/platform-specific/nrf/trustzone/secure-world/build/nrf/nrf5340/dk/application/secure-world-example.hex -Intel \
   examples/rpl-udp/build/nrf/nrf5340/dk/application/udp-server.hex -Intel \
   -o merged.hex -Intel

  4. Flash the network core and merged application core.

See examples/platform-specific/nrf/ipc-radio-service/README.md for the complete step-by-step instructions.

GPIO Forwarding (Legacy)

An alternative approach is to run the full OS on the network core and use the application core only to start the network core and forward GPIO pins. This is provided by the start-network-core example:

make TARGET=nrf BOARD=nrf5340/dk/application start-network-core.upload

Once the application core contains this example, a Contiki-NG application can be uploaded to the network core:

make TARGET=nrf BOARD=nrf5340/dk/network hello-world.upload

The start-network-core example forwards UART, buttons, and LEDs. If extra GPIOs are needed on the network core, they must be forwarded in start-network-core.

Support

For bug reports or/and suggestions please open a github issue.

License

All files in the port are under BSD license. The nrfx is licensed on a separate terms.

Resources