nRF52840 IEEE802.15.4 Thread Stack

[_Dejan_]

Hi everyone,

Im new in embedded world so first sorry for maybe stupid or basic questions... Also there is not a lot of information about nRF52840 and IEEE802.15.4 :) Im receive nRF52840 board and build some demos and examples on it... Some work normaly and some BLE examples doesn't work(probably because there is not connected some device/sensors)...

First I would like explain what I would like to achieve... I would like to make:

• Sensor device(can have different sensors) which is battery powered and periodicly send data to main unit

• I/O device which is powered by external power supply and send data to main unit when input is triggered and change output state when receive data from main unit

• Main unit (have also some I/O) which is powered by external power supply store all data, control devices ... It will have also external MCU with LAN/WIFI/GPRS network support.

1.) As I know if I use bluetooth for connections Im limited to 8 connections which is not enough, ANT is not free so 802.15.4 will be best for me... I would like build secure mesh network and find Thread stack. Im also find that OpenThread stack on github have support for nRF52840 and some examples is this same as Thread stack?

2.) Sensor device will most time be in sleep to save battery so it will be "Leef device", i/o device in main unit will be all time powered on. i/o device can be also used as range extender so it will be "REED/router device ". Main unit will be "Border Router". Can this be done?

3.) Is 802.15.4 and Thread already suported and implemented on nRF52840? If not is there any esimated time when it will be?

4.) Do I need if I want use 802.15.4 and Thread(or OpenThread) also use SoftDevice? Or it work without SoftDevice? If I need it which one?

5.) Does Thread(or OpenThread) stack use CryptoCell 310 library to encrypt connection?

6.) I didn't check and try OpenThread examples but can be used directly on device without computer(like in example)? I don't see reason why not...

Thanks for any help and answers to my questions.

[Krzysztof Loska]

Hi,

Recently Nordic launched its first Thread networking solution.

Nordic provides full support for its platform within OpenThread and actively participates in the development of OpenThread by co-authoring the core of this stack. It is true that we released support for nRF52840 on OpenThread repo a few weeks earlier but we did not want to announce anything until we would have a proper SW solution which is not only a stack but also related Software Development Kit with examples, documentation etc. Our platform appeared publicly on OpenThread repo early because it was much simpler for us to collaborate with Google Nest on the project being on the master branch.

To facilitate Thread products development with the nRF52840 platform, Nordic Semiconductor provides nRF5 SDK for Thread and nRF Thread Topology Monitor PC tool.

The nRF5 SDK for Thread v0.8.0 includes:

• a pre-built OpenThread stack for the Nordic nRF52840 SoC with ARM CryptoCell-310 support,
• unique support for DFU-over-Thread (Device Firmware Upgrade),
• examples to demonstrate interactions between nodes performing different Thread roles with the use of OpenThread and built-in CoAP protocol,
• support for an OpenThread Network Co-Processor (NCP),
• Border Router and cloud connectivity example,
• Thread native commissioning with NFC example,
• range of PC tools including a Thread Topology Monitor,
• software modules inherited from the nRF5 SDK e.g. peripheral drivers, NFC libraries etc.

Important notice - hardware-accelerated cryptography

Due to legal restrictions support for hardware-accelerated cryptography utilizing ARM CryptoCell-310 is only available in mbedTLS library (libmbedcrypto.a) provided with the nRF5 SDK for Thread. The library available in OpenThread repository does not support hardware acceleration. You can still use it, but the commissioning procedure takes much more time in such case. For the best performance and user experience, use the library provided with the SDK.

Important notice - Certification

OpenThread is an open-source implementation of Thread standard. You can use it without any restrictions in the development phase. However, your device must meet Thread Group standards and must be a certified product before being marketed as a Thread product. Detailed information about product certification are available for Thread Group members at Contributor and Sponsor tiers (threadgroup.org/joinus).

[_Dejan_]

Thanks for this info. I will look into new SDK :)