RAK3172 - Low level development - STM32

WisBlock
1

Hello Rak forum!
Our company has been developing prototypes. We are currently working on a board where we integrate a Laser ToF and AHT20 sensor in our pcb.
Our current setup has been a ESP32 + a third party lora module for lorawan. The communication between ESP and module happend via UART with AT commands (like the rak can do)

However, we’ve ordered and played around with both the 11720 and 3172. We had more issues with the 11720 then the 3172 - Especially with it going unresponsive, and needing a physical tool to reflash it once it goes bad. We had one chip that arrived DOA and another one that become unresponsive soon after. We’ve reached out to support.

For now, we’re focusing on 3172 - And tested with arduino and RUI3. This is a very good experience and it worked exactly as expected - With our initial power measurements going down to 25ua (Including the sensors, etc) in sleep. Cool!

What is the benefit of going directly via STM32ide and writing our program there, vs going via RUI3. Are there any power benefits? We are not doing anything real-time or alike.

I followed the guide and got to send a custom payload via low development - Simple hello world, however, adding our ToF and AHT20 sensor seems like a larger task than in arduino for now.

My question is simply:
Is there any real benefit for us in this current stage for going directly via stm32ide vs just using RUI3?

We’re shipping our first batch of PCB’s with the rak soon, I think its around 100 3172 - We hope its going to run well!

Regards,
Kevin

2

Welcome to the forum @kevinals

You already listed one advantage, you can use existing libraries for sensors and peripherals instead of re-writing the code to use them.

The other advantage is that we have a tested LoRaWAN stack (LoRa Alliance certified) that makes sure that you don’t need to worry about bugs with the LoRaWAN communication.

RUI3 is already optimized for low power consumption, but I have no comparison with devices that run a firmware compiled with the STM32CubeIDE.

I am sorry to hear about your problems with the RAK11720. Can you tell us what version of RUI3 you were using on the RAK11720.
There have been many improvements in RUI3 for the RAK11720, including a new bootloader that eliminates the unresponsive state, e.g. after a firmware download failed.

3

Hi @beegee
First and foremost, thank you for taking your time to answer my post (especially on a sunday!)

I’m happy to hear that while you have no direct comparison, it seems like you are recommending RUI3. We were also pretty happy with the current power consumption. I was just trying to understand what benefit it would have to compile the firmware ourselves.

I see the positive site for using RUI3 that we only need to write code once for both 3172 and 11720

For the RAK11720, it was the firmware that was shipped, we never got around to checking it before they died. So im unsure what firmware they were on.