Working with nRF52 Series¶

Introduction
Supported protocols
Multiprotocol support
FOTA upgrades
Building and programming a sample

The nRF Connect SDK provides support for developing on all nRF52 Series devices and contains board definitions for all development kits and reference design hardware.

See Getting started with nRF Connect SDK (nRF52 Series) for step-by-step instructions on how to test and develop with an nRF52 Series development kit.

Introduction ¶

The nRF52 Series of System-on-Chip (SoC) devices embed a powerful yet low-power Arm Cortex-M4 processor with our industry leading 2.4 GHz RF transceivers. All of the nRF52 Series SoCs have support for Bluetooth® 5 features, in addition to multiprotocol capabilities.

See nRF52 Series for the technical documentation on the nRF52 Series chips and associated kits.

Supported boards ¶

Devices in the nRF52 Series are supported by these boards in the Zephyr open source project and in nRF Connect SDK.

DK	PCA number	Build target	Documentation
nRF52840 DK	PCA10056	`nrf52840dk_nrf52840`	Product Specification User Guide
nRF52811 emulation on nRF52840 DK	PCA10056	`nrf52840dk_nrf52811`	Product Specification
nRF52833 DK	PCA10100	`nrf52833dk_nrf52833`	Product Specification User Guide
nRF52820 emulation on nRF52833 DK	PCA10100	`nrf52833dk_nrf52820`	Product Specification
nRF52 DK	PCA10040	`nrf52dk_nrf52832`	Product Specification User Guide
nRF52810 emulation on nRF52 DK	PCA10040	`nrf52dk_nrf52810`	Product Specification
nRF52805 emulation on nRF52 DK	PCA10040	`nrf52dk_nrf52805`	Product Specification
nRF52840 Dongle	PCA10059	`nrf52840dongle_nrf52840`	Product Specification User Guide
nRF21540 DK	PCA10112	`nrf21540dk_nrf52840`	Product Specification

See nRF21540 EK to learn how to use this RF front-end module (FEM) with the nRF52 Series devices.

nRF Desktop ¶

The nRF Desktop application is a complete project that integrates Bluetooth Low Energy, see the nRF Desktop application. It can be built for the nRF Desktop reference hardware or an nRF52840 DK.

The nRF Desktop is a reference design of a HID device that is connected to a host through Bluetooth Low Energy or USB, or both. This application supports configurations for simple mouse, gaming mouse, keyboard, and USB dongle.

Secure bootloader chain ¶

nRF52 Series devices support a secure bootloader solution based on the chain of trust concept.

See Secure bootloader chain for more information and instructions on how to enable one or more bootloaders in your application.

Supported protocols ¶

The nRF52 Series multiprotocol radio supports Bluetooth Low Energy, proprietary (including Enhanced Shock Burst), ANT, Thread, Zigbee, and 802.15.4. Standard interface protocols like NFC and USB are supported on a range of the devices in the series and with supporting software.

Note

nRF Connect SDK currently has no support for ANT.

The following sections give pointers on where to start when working with these protocols.

To test the general capabilities of the 2.4 GHz radio transceiver, use the Radio test sample.

Bluetooth Low Energy ¶

When you develop a Bluetooth Low Energy (LE) application, you must use the Bluetooth software stack. This stack is split into two core components: the Bluetooth Host and the Bluetooth LE Controller.

The nRF Connect SDK Bluetooth stack is fully supported by Nordic Semiconductor for nRF52 Series devices. The Bluetooth LE Controller user guide contains more information about the two available Bluetooth LE Controllers and instructions for switching between them.

See Bluetooth for documentation on the Bluetooth Host and open source LE Controller. For documentation about the SoftDevice Controller and information on what variants of the controller support which chips, see SoftDevice Controller.

The nRF Connect SDK contains a variety of Bluetooth samples that target nRF52 Series devices. In addition, you can run the Bluetooth samples that are included from Zephyr.

For available libraries, see Bluetooth libraries and services (nRF Connect SDK) and Bluetooth (Zephyr).

Enhanced ShockBurst ¶

Enhanced ShockBurst (ESB) is a basic protocol supporting two-way data packet communication including packet buffering, packet acknowledgment, and automatic retransmission of lost packets. ESB provides radio communication with low power consumption, and the implementation is small in code size and easy to use.

See the Enhanced ShockBurst (ESB) user guide for information about how to work with Enhanced ShockBurst. To start developing, check out the Enhanced ShockBurst: Transmitter/Receiver sample.

Matter ¶

Matter (formerly Project Connected Home over IP or Project CHIP) is an open-source application layer that aims at creating a unified communication standard across smart home devices, mobile applications, and cloud services. It supports a wide range of existing technologies, including Wi-Fi, Thread, and Bluetooth® LE, and uses IPv6-based transport protocols like TCP and UDP to ensure connectivity between different kinds of networks.

Matter is in an early development stage and must be treated as an experimental feature.

See the Matter (Project CHIP) user guide for information about how to work with Matter applications. To start developing, check out Matter samples.

Near Field Communication ¶

Near Field Communication (NFC) is a technology for wireless transfer of small amounts of data between two devices that are in close proximity. It makes transferring data fast and easy when devices are in close proximity. The range of NFC is typically <10 cm.

nRF Connect SDK provides two protocol stacks for developing NFC applications: Type 2 Tag and Type 4 Tag. These stacks are provided in binary format in the sdk-nrfxlib repository. See Near Field Communication (NFC) for documentation about the NFC stacks, and Near Field Communication (NFC) for general information.

The NFC stack requires the NFCT driver for nRF52 devices, which is available as part of nrfx. The nrfx repository is included in the nRF Connect SDK as a module of the Zephyr repository.

See NFC samples and Libraries for NFC for lists of samples and libraries that the nRF Connect SDK provides.

USB ¶

The nRF Connect SDK contains a USB device stack for the USB 2.0 Full Speed peripheral that is available on a number of the nRF52 devices. You can find the implementation in the Zephyr repository. See USB device stack for documentation and USB Samples for a list of available samples.

The USB stack requires the USBD driver for nRF52 devices, which is available as part of nrfx. The nrfx repository is included in the nRF Connect SDK as a module of the Zephyr repository.

Thread ¶

Thread is a low-power mesh networking technology, designed specifically for home automation applications. It is an IPv6-based standard that uses 6LoWPAN technology over the IEEE 802.15.4 protocol. You can connect a Thread mesh network to the Internet with a Thread Border Router.

The nRF Connect SDK provides support for developing Thread applications based on the OpenThread stack. The OpenThread stack is integrated into Zephyr.

See the Thread user guide for information about how to work with Thread. To start developing, check out the Thread samples.

Zigbee ¶

Zigbee is a portable, low-power software networking protocol that provides connectivity over a mesh network based on the IEEE 802.15.4 radio protocol. It also defines an application layer that provides interoperability among all Zigbee devices.

The nRF Connect SDK provides support for developing Zigbee applications based on the third-party precompiled ZBOSS stack. This stack is included as the ZBOSS Zigbee stack library in nrfxlib (version 3.8.0.1). In combination with the integrated Zephyr RTOS, Zigbee in nRF Connect SDK allows for development of low-power connected solutions.

See the Zigbee user guide for information about how to work with the Zigbee protocol and stack. To start developing, check out the Zigbee light switch sample.

Multiprotocol support ¶

The nRF52 Series devices support running another protocol in parallel with the SoftDevice Controller. See the Multiprotocol support user guide for instructions on how to enable multiprotocol support for Thread or Zigbee in combination with Bluetooth.

The Multiprotocol Service Layer library provides services for multiprotocol applications.

FOTA upgrades ¶

You can upgrade the firmware of the device over the air, thus without a wired connection. Such an upgrade is called a FOTA (firmware over-the-air) upgrade. FOTA upgrades can be used to replace the application.

Note

There is currently no support for upgrading the bootloader (MCUboot) on nRF52 Series devices.

To perform a FOTA upgrade, complete the following steps:

Make sure that your application supports FOTA upgrades.
To download and apply FOTA upgrades, the following requirements apply:
- You must enable the mcumgr module, which handles the transport protocol over Bluetooth Low Energy. To enable this module in your application, complete the following steps:
  1. Enable CONFIG_MCUMGR_CMD_OS_MGMT, CONFIG_MCUMGR_CMD_IMG_MGMT, and CONFIG_MCUMGR_SMP_BT.
  2. Call os_mgmt_register_group() and img_mgmt_register_group() in your application.
  3. Call smp_bt_register() in your application to initialize the mcumgr Bluetooth Low Energy transport.
  See the code of the SMP Server Sample for an implementation example. After completing these steps, your application should advertise the SMP Service with UUID 8D53DC1D-1DB7-4CD3-868B-8A527460AA84.
- To upgrade the application, you must use MCUboot as the upgradable bootloader (CONFIG_BOOTLOADER_MCUBOOT must be enabled).
Create a binary file that contains the new image.
To create a binary file for an application upgrade, make sure that CONFIG_BOOTLOADER_MCUBOOT is enabled and build the application as usual. The build will create several binary files (see Using MCUboot in nRF Connect SDK). The app_update.bin file is the file that must be downloaded to the device.
Download the new image to a device.

Note

When performing FOTA upgrade on a Bluetooth mesh device and if the device’s composition data is going to change after the firmware upgrade, unprovision the device before downloading the new image.

Use nRF Connect for Mobile or nRF Toolbox to upgrade your device with the new firmware.

To do so, make sure that you can access the app_update.bin file from your phone or tablet. Then connect to the device with the mobile app and initiate the DFU process to transfer app_update.bin to the device.

Note

There is currently no support for the FOTA process in nRF Connect for Desktop.

Building and programming a sample ¶

To build your application, follow the instructions in Building and programming an application.