RAK 3172 doesn't respond to AT commands

I am currently developing a project where I use a RAK3172 chip but I can’t get any response for the AT commands.

The RX keep responding with something, but the specific AT commands never get a response.

All the connection pins are correct. I have certified that.

Does anybody have some thoughts on it?

Hi @gabrielbklopes . Welcome to RAK forum :slight_smile:

Please use 9600 baud rate for RAK3172. That is the default baud rate.

Hey @carlrowan,

Thanks for your answer.

I have tried 9600 baud rate as well and I keep getting the same response.

Oh. That’s strange RX.

Few things we can check:

Are there other devices connected to your USB port? If there is/are, can you disconnect all and just leave RAK3172. Btw, is you RAK3172 a module, breakout board or evaluation board? Also just to confirm, you have no AT command reply yet since you use the device? Did you tried to upload a different FW?

I have removed all the USB ports.

My RAK3172 module is attached to a evaluation board.

For the AT commands I couldn’t receive any reply at all.

Do you have another FW I could try? The only FW I have is the one provided by RAK documentation.

Are you using this evaluation board Evaluation Board | RAK3172-E – RAKwireless Store or a custom one? Are you sure with the COM Port selected? Have you tried to plug it out and plug in again? Have you tried a different Terminal software like Termite?

This is the official RAK3172 FW link we have RAKwireless Downloads

Hello again Carl,

Thank you for the response.

I got a question: the FW you provide is the Application or the bootloader? As you can see in the image below, there is a .bin file only with App and a .hex file with boot+app. Which one should I try? Also I have tried the Low_Level_Development FW and it doesn’t work as well.

Hi Gabriel,

If you are going to upload a new FW using the RAK DFU Tool, you need the .bin file. That will upload only the application FW and the bootloader code in the module won’t be affected. All RAK3172 modules have the RAK wisduo bootloader in it upon shipping to customers and also with the latest application FW. Therefore all RAK3172 should be usable right out of the box.

But if you are going to upload a new FW using STM32CubeProgrammer, you need to upload the .hex file. It contains the Bootloader and the Application FW. That will override the bootloader section as well. I suggest this is the one you do so that everything will be wiped out and you’ll have a clean slate.