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.

[Jørgen Holmefjord]

1. The S132 v4.0.0 softdevice support up to 20 connections (where up to 4 can be as a peripheral). We also provide proprietary Mesh solution over BLE (note that this is based on scanning and broadcasting, not connections). Otherwise, Thread should be a great solution for your project.

3. Please contact your regional sales manager for details about future releases and roadmap questions. If you do not know who this is, please message me your location and I will provide contact details.

4. Currently, softdevices is BLE and ANT stacks. Whether the 802.15.4 software will be a new softdevice or some kind of library, I cannot comment on at this point. You should not need any of the current softdevices. The OpenThread example will generate a single file that you need to flash to your board.

5. The CryptoCell library is intended for use by the application. As we currently don't provide any Thread support, I cannot say whether or not this will be used in a Thread implementation. I doubt that OpenThread use the CryptoCell.

6. The way the OpenThread nRF52840 example is setup, you need to configure each device through a terminal. You can propably be change the example code to do this by default when the device boots up.