DWM3000 and DWM1000 to RAK4631 on an nrf52840

[wassfila]

Question posted by @bodhibrata
#1 (comment)

Hi wassfile,

Thanks a lot for your hard work. I am Bodhibrata an embedded enthusiast. I plan to interface DWM3000 and DWM1000 to RAK4631 which has an nrf52840. I prefer to use Arduino IDE based programming, can you please suggest some libraries?

I have never used zephyr and have no idea about it.

[wassfila]

@bodhibrata, why don't you rather use DWM3001C, it already has a nRF52833 which has all nRF52840 capabilities such as Thread and Zigbee. Do you have a particularly large program to fit in?
As an enthousiast, or even as a researcher whom focus is not large series with low hw cost, I do not recommend to initiate a custom pcb design, rather to use an existing dev kit for sw already exist, and you run it and modify the app that comes with it.
What is it that you want to learn ? PCB design, UWB or embedded sw ?

• PCB : rather start with simpler projects, not uwb rf
• UWB : start with ready to use dev kit
• embedded sw : start with hello world Zephyr examples on simple hw such as nRF52840 USB dongle

in my small experience with UWB, I do not recommend Arduino, see sw survey https://www.homesmartmesh.com/docs/networks/ultrawideband/#software-survey

With limited debug capability, Arduino projects with uwb become much harder than with other frameworks. I nevertheless do not exclude that someone maybe developped the exact arduino lib you're looking for. If you find such libs, please post ;)

[bodhibrata]

Thanks a lot for the reply. I need to integrate a UWB module with an existing controller that is already connected to other sensors. Codes of those sensors are already written So, I purchased DWM3000 and DWM1000 modules and planned to interface them with ESP32 or nrf52840. I am more interested in understanding UWB and using it for localization efficiently.

Please let me know if I can use Zephyr to program RAK4631 over serial. Also, do Zephyr will support other libraries like LoRa etc. for RAK4631. I don't have a dedicated programmer for nrf52840. Kindly suggest

I came across some ESP32 libraries for DWM1000: a) https://github.com/thotro/arduino-dw1000 b) https://github.com/F-Army/arduino-dw1000-ng

[wassfila]

Which sensors do you want to use ? Temperature, humidity, pressure, light, air quality ?
Zephyr is the os used in the official Nordik SDK for nRF52, but I do not recommend it, unless you want to learn hiw to use Real Time Operating Systems. You'd be much faster with Arduino, but then with Arduino, you can only run one thing at a time and limited to libraries that already exist, also combining things to run in parallel is not possible without rtos. You can measure, then send uwb cyclically, it won't be high performance, but it'll work.
So what's your preferred uC nRF52 or ESP32 ?
nRF52 neds to be flashed with swd, or use a bootloader that yiu flash yourself (it comes with the usb dongle preflashed though) while ESP32 has it hardcoded, much easier for beginners.
Will you solder a pcb yourself or will you mount on a breadboard ? uwb can be sensitive to dangling wires interferences.

[bodhibrata]

Thanks a lot, if I plan to use UWB with nRF52 (RAK4631) then I need to use its Lora module. I am interested in learning RTOS as it has a lot of advantages. Please let me know if Zephyr has a LoRa library and how can I program RAK4631 with Zephyr. Do I need an additional programmer?
I will solder myself and will not use breadboard as it is not reliable.

[wassfila]

For now, I do not see DWM3000 or DWM1000 possible with RAK4631 on nRF52840. Here are more details why and I can also guide you through what you want to achieve.

I suggest you split the effort in two parts :

• Learning RTOS Zephy
• Looking for ready libraries and frameworks that support your HW and sensors

Do not let Zephyr be your only option because it's learning curve is steep. You'd feel comfortable with Zephyr in case you had prior Linux kernel dev experience, not the easy Linux user space usage and command lines, the kernel. Even if you don't you'll still get used to it by learning the basics, these are a bunch of tools you need to master to be able to handle Zephyr :

• git
• Cmake
• Kconfig

getting started with Zephyr starts right here : http://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/zephyr/develop/getting_started/index.html#getting-started
An easier way to get everything installed is through the nRF Connect SDK
http://developer.nordicsemi.com/nRF_Connect_SDK/doc/latest/nrf/gs_assistant.html

I had a look at RAK4631 in here https://store.rakwireless.com/products/rak4631-lpwan-node?variant=37505443987654
That is for LoRA WAN, I don't think you'll be able to combine UWB with LoRA, you need to find a module that is already designed to do that. It's not only about finding a library. Such RF low level drivers needs uC HW resources like timer or other modules, and once taken by a lib, other libs have to either share them or use them exclusively, that is not something possible at application level, that is like writing new drivers. Also which PIOs will you use to connec UWB modules ? As in the RAK you only have SWD exposed.

As a beginner, I suggest you rather try to exclusively run existing ready applications with very well defined frameworks, once it works and you get confident about the framework, that's when you start combining, editing and writing new drivers, do not set too high hopes before experiencing something real first.

About soldering yourself. Will you design a custom PCB or solder wires directly on the modules ? The pins are quite tight.
The bi pios exposed are actually the SWD programming pios,

For programming through those pios you need a programmer such as
https://www.segger.com/products/debug-probes/j-link/models/j-link-edu/
or even cheaper
https://www.segger.com/products/debug-probes/j-link/models/j-link-edu-mini/
The nRF52 USB dongle is the only dev kit that can be flashed without programmer, all others need one.

The good news is, the RAK4631 is already supported by Zephyr aDTS exist which means you can use Zephyr drivers out of the box. I just installed the latest nRFSDK v1.9.1 there you have under path
zephyr\boards\arm\rak4631_nrf52840\rak4631_nrf52840.dts
Or here directly the doc link
https://docs.zephyrproject.org/latest/boards/arm/rak4631_nrf52840/doc/index.html

You might search for tutorials or videos to help you with the specific case og RAK4631 and Zephyr such as
https://news.rakwireless.com/hands-on-with-rakstars-episode-25-with-guillaume-paquet/

So for now, I do not see DWM3000 or DWM1000 possible with RAK4631 on nRF52840. I will close this thread and if you need support with another scope, you can create another ticket, only if you find elements that shows DWM possible with RAK you can keep posting them in this thread. I try to keep discussions within the title scope, and does not matter how many we run in parallel.

[bodhibrata]

Thanks a lot, @wassfila for the valuable information you shared.