RAK4631 no longer able to get into bootloader mode after UF2

WisBlock
1

I have 3 RAK4631 meshtastic kits I wanted to convert to RUI3. Need them for a GPS project.

using WiseToolBox the update to RUI3 fails. but at that point its erased the firmware.

I was able to double tap the rest button and they would enter into bootloader mode and they would show up as a drive.

I was then able to sucessfully update the Ardunio bootloader 0.4.3 dated May 20 2023

process goes as expected until I drag and drop the most current meshtastic UF2 file.

file trasfers unit then bricks it self.

I am unable to get the unit into DFU mode after that. I have 2 units that exibit the exact same behavior.

How do I gain acess to these boards to restore the factory bootloader and firmware ?

2

Welcome back to RAK forum @AngryMonkey ,

I am not sure what happened on your modules but if it is not detected as COM port or external drive (and your hardware is ok - USB cable good, PC connection ok, no issue on power, etc.) then you might need to reupload the bootloarder using external tools like Jlink or RAKDAP1.

Jlink Guide
RAKDAP1 Guide

PS, your initial message is confusing since you are converting to RUI3 by using WisToolBox. Meshtastic RAK4631 will not work on WisToolBox. WisToolBox only work on RUI3 RAK4631-R.

3

Thank you for the response. let me clarify, inventory is sparse here in the states, we get our stuff from Rokland but we get the meshtastic kits from amazon.

the RAK4631 Arduio bootloader does not interface well with WiseToolBox but it offers to do an upgrade to RUI3. it fails every time. it did not used to fail.
WiseToolbox lets you manualy select the RAK4631 and then gives you a nice large “updrade to RUI3” button.

on the bricked units I was able to sucessfully flash the bootloader with a DAPLINK and pyocd. so I was able to recover the bricked units. used the most uptodate HEX file. So all is well in my world …

I am simply going to flash via the DAPLINK… in the future.

Thanks for your Support !