Introducing the nRF Connect SDK, the Zephyr RTOS-Based SDK for Short-Range and Cellular IoT Apps

The nRF Connect SDK is a Software Development Kit (SDK) for rapidly developing applications based around the open source Zephyr Real Time Operating System (RTOS). It contains the features and protocols necessary to develop both short-range and long-range applications for the nRF5340 SoC and the nRF9160 SiP. The next version of nRF Connect SDK (v1.3) will have code and documentation support for the nRF52 Series.

The nRF Connect SDK is part of the nRF Connect umbrella, our one stop platform for developing both short-range and long-range applications. In addition to the nRF Connect SDK, the nRF Connect umbrella also includes nRF Connect for Desktop and nRF Connect for Cloud, as well as mobile apps such as nRF Connect for Mobile. nRF Connect for Desktop contains tools to quickly test features and enhance debugging capabilities on both our short and long-range products. nRF Connect for Cloud is cloud platform for evaluating and testing our long-range cellular IoT nRF9160 SiP. Lastly, nRF Connect contains smartphone apps that help evaluate our Bluetooth Low Energy (Bluetooth LE) based solutions and can be used as a starting point for smartphone app development.

nRF Connect SDK is based around the open source Zephyr RTOS, a low power RTOS driven by the independent Linux Foundation project. Some of the main benefits of an RTOS include abstracting away HW and scheduling complexity, allowing important processes to finish in a deterministic fashion. See this blog post for more information on RTOS and their benefits. As applications become more complex, require more processing threads and multiprotocol solutions become more standard, an RTOS can help manage application complexity.

Nordic Semiconductor and others help drive the Zephyr project forward by actively contributing to the code base. Over 600 embedded industry experts actively contribute, maintain and test the Zephyr project, ensuring a robust and efficient solution. Zephyr's own security subcommittee ensures that security is prioritized. The open source MCUBoot also provides a secure bootloader for over the air firmware updates and secure booting of application code.

One of the main benefits of the nRF Connect SDK is modular programming. Zephyr includes all the main wireless protocols, including but not limited to Bluetooth LE, Bluetooth mesh, CoAP, UDP, MQTT, IPv4, Ipv6, etc. By including these robust protocols, it allows Nordic Semiconductor to focus on other value adding features, such as modem and application Firmware Over the Air updates on our nRF9160 SiP. Modular programming also means that the developer can decide which modules, libraries and drivers to support to ensure high memory efficiency. This gives the nRF Connect SDK flexibility in supporting small, memory constrained applications all the way up to complex and richly featured software for advanced applications. The single code base for both our short-range and cellular IoT products allows easy code re-use between multiple applications. This minimizes the time investment for customers developing multiple applications based around nRF Connect SDK.

The main goal of the nRF Connect SDK is to simplify the process of bringing a product to market. Simple sample applications can be used by customers to build a simple proof of concept, then a prototype and finally a finished product.

A new toolchain manager application in nRF Connect for Desktop allows a quick setup of the toolchain and nRF Connect SDK on Windows PCs even without administrator privileges. The nRF Connect SDK is hosted on Github with permissive Nordic 3 and 5-clause BSD and Apache 2.0 licenses. The toolchain includes tools such as git and west for enterprise repository management, as well as free IDE support for Nordic products with Segger Embedded Studio Nordic Edition. West is a Zephyr based command line tool to build and flash code, as well as keep the nRF Connect SDK repositories up to date. After the nRF Connect SDK is branched, the developer can choose to contribute back to the SDK, but also have private repositories for sensitive intellectual property.

nRF Connect SDK development has been ongoing for more than one year and contains support for our short-range nRF5340 SoC, as well as production support for our long range nRF9160 SiP. nRF Connect SDK v1.2 has already been released and the next version of nRF Connect SDK (v1.3) will have code and documentation support for the nRF52 Series. Code and documentation supporting the nRF52 Series are already available in the latest master branch of development. Production quality code for the nRF52 Series and nRF53 Series is arriving soon.