Using nRF52840 for 802.15.4

[RobC]

I would like to use the nRF52840 for 802.15.4 but it is rather vague in the OPS as to how to do this. I can figure some of it out but not other parts.

• It mentions "assisted" mode but it is not clear how this is programmed or indeed how it actually works. The name suggests hardware assistance for 802.15.4 MAC, e.g. auto CCA, auto ack. etc. I can see there is some sort of assistance through use of the shortcuts; is that what is meant by "assisted"? Is there any more detail on this?
• It is not clear how the two address types in 802.15.4 are used wrt. DAB and DAP, or indeed if there is any address matching for 802.15.4?
• Can you provide examples of how PCNF0 and PCNF1 should be programmed? My guess is that the only significant value in PCNF0 for 802.15.4 is the preamble length.

[bjorn-spockeli]

Hi Rob,

Q1: I agree that the OPS does not describe what this assisted mode and how it is implemented(i.e. HW or SW), but I am assuming that the OPS refers to the features mentioned in the introduction of the IEEE 802.15.4 Operation section, i.e.

• Clear Channel Assessment
• Energy detection scan
• CRC Generation

We do not have any hardware support for Auto-acking as far as I know. However, I will ask the author of the OPS to clarify what we're mean with "assisted mode".

Q2: The DAB and DAP registers are used only for BLE, we do address matching in software for 802.15.4.

Q3: I suggest that you take a look at our OpenThread repo, found here on GitHub, when it comes to using the nRF52840 radio for 802.15.4. Specifically, I suggest that you take a look at this and this file.

If I may ask, do you plan on using Thread or are you looking into starting from scratch, i.e. develop your own 802.15.4 stack?

Best regards

Bjørn

[Krzysztof Loska]

Hi,

Also if you look for some explanation beyond the code look here for a description or here for UML diagrams (you need PlantUML app to open them).

[RobC]

Thank you for the pointers - it is all much clearer now.