Trying to update I-NUCLEO-LRWAN1 --> Error "sm42 interface seems abnormal"

[ANauz.1]

Hello,

I'm trying to update the firmware of my I-NUCLEO-LRWAN1. But before that, I would like to backup the firmware. I'm trying to use the sm42_fw_update_tool found here:

https://github.com/USIWP1Module/USI_I-NUCLEO-LRWAN1

I got the same error seen here:

https://community.st.com/s/feed/0D50X00009XkW6ZSAV

"sm42 interface seems abnormal"

Using ST-Linkk Utility (version 4.6)I was able to:

• update STLink Firmware
• connect to the target
• Set "Read Out Protection" to level 0

So I can read Device ID/Flash Size/family. SWD interface is ok.

But still, I have the same error "sm42 interface seems abnormal"

I'm using as parameter the number of the "STLink Virtual COM Port", but maybe am I wrong?

What I am missing?

Thank you

[Tesla DeLorean]

Ok, you can't backup firmware on a device protected with read-out protection.

If you tried to remove read-out protection you will have erased the device. USI's firmware would not be present, and you won't be able to upgrade the firmware.

[ANauz.1]

Just one more question. If the firmware is erased, why is the upgrade no more possible? It should be possible to update with SWD no? It do not need firmware?

[Tesla DeLorean]

You can push in your OWN firmware via SWD, as I recall they explain the pin usage/mods needed to work with the LRWAN code.

What they don't provide is their own raw firmware image for you to write via SWD.

They might be able to export an encrypted copy, like their updates, but that requires some firmware to be running/functional, and you've erased that and the encryption keys.

Now all you'll be able to do is build your OWN firmware, and use that.

[ANauz.1]

Arghhhh!!! Ideed, module is not working anymore!

I do not understand why USI provide a backup script for a module that cannot be backuped!

I will try to get the .bak file.

It seems that you are working on thoose module. Do you have a working procedure to update them? (When you have the .bak file)

Thank you

[Tesla DeLorean]

I think they allow for an encrypted backup to be extracted, however you look to have blown past that opportunity, and just removed all firmware from the device, including their application and boot loader.

Several years back I built a firmware with the LRWAN package to go onto the USI module. I think they enumerated the pin and rx/tx switching changes that you would need to make to existing SX1272 radio code. You'd likely need to fork a project to the L0 part they use, modify the board support, and radio code.