STM32 Nucleo Board STLINKV3 dead

[mdede439]

Hi all.  I have an issue I need help with.  I have a STM32 Nucleo Board for the STM32WL55JC1 and I used STM32CubeProgrammer to update the STLINKV3 code and it failed close to the end.  Now the board is not recognized by the update utility.  It says the current firmware is unknown and it doesn't know how to upgrade it.  It is not recognized by STM32CubeIDE either.  I can use the STLINK from another board to program it so I know the target MCU works but the STLINK MCU is toast. It does kind of work because Windows does see it as a "disk" and I can see a couple files on it.  As well as STM32CubeProgrammer does report the serial number of the device but cannot connect to it.

Does anyone have any ideas how to recover from this? How to possibly re-flash it?

Appreciate any help.  Thanks

Mike.

[Robotec]

what i would do it to reflash the st link on my own, i think you bricked it.

Here this guy got the flash of one ST link V3 so it should be possible to upload it to your bricked stlink thought the other one you mentioned.

https://hackaday.io/project/179054-custom-st-link-v20-v21-v30

In ST you got the design files(https://www.st.com/en/evaluation-tools/nucleo-wl55jc.html#cad-resources), to flash the st link chip again you have to connect to the reserved port CN2 with pinout SWDIO-GND-SWCLK-3.3V

should be easy to do with STM32CubeProg.

[mdede439]

Thanks for the links! lots of great info there.  I did find the schematics already and the CN2 pins but not sure how to actually re-flash it using them.    Don't I need to bring BOOT0 high to re-flash it?  I am a bit new to using STM32.  As far as I can tell from the PCB layout BOOT0 is routed to ground and there is no way to bring it high.  Also there are a pile of jumpers on the NUCLEO-WL55JC and some seem to power the ST-LINKV3 MCU so I am not sure if I got one of those set wrong too. I am at a loss here.  I can't seem to figure this out.

[Robotec]

Its really easy dont worry, there is no need to pull boot0 high, thats for booting and you are flashing, just connect  3v3 to Vdd, swdio to swdio and so on, then download stm32cube programmer and select software reset, the flash file from the hackaday guy and you are done

[mdede439]

Thanks for your reply!! 

I have tried that and the STLINKV2.1 on my working Nucleo Board does not find the STM32 target (meaning the STLINKV3 of the the failing board).

Let me explain how I understand this works and maybe there is something fundamental I am missing.

I have a pin header on the CN2 connector of the Nucleo-WL55JC1(failing board).  I have these pins SWDIO, SWCLK, Gnd, and 3V3_STLK connected to my other Nucleo board configured for external programming.  3V3_STLK -> VDD_TARGET,  SWCLK -> SWCLK,  SWDIO -> SWDIO, and Gnd-> Gnd. As far as I understand it the 3V3_STLK -> VDD_TARGET connection is used to measure what the target MCU voltage, it does not provide the power to the target MCU.  So I have the failing Nucleo board plugged in to provide power to the STLINKV3 MCU.

After connecting the two boards up this way, STMCubeProgrammer finds the working STLINKV2.1 but does not find any target MCU, which should be the failing STLINKV3 MCU.   Either I am still doing something wrong or more is wrong with STLINKV3 MCU. I even metered out the short jumpers I am using to connect the boards and they check out.

[Robotec]

Check voltaje on the target and if It is 3.3V and not detecting It..bad news, try contacting st support because i would say its a dead chip and maybe that was the cause of not upgrading correctly in first place.

[mdede439]

Thanks for the suggestions.  I have checked and it looks like the STLINK chip does have 3.3V.  I measured the voltage at some of the decoupling capacitors. I am pretty sure the chip is working because I do see it connected to my USB and does create a "drive" on my Windows 10 machine.  I can read some files off of it.  But the firmware revision level is all wrong.  Also STM32CubeProgrammer does see the device's serial number. My best guess as to what happened was the firmware got corrupted during the upgrade or something failed during the upgrade and it left the device in a corrupted state.  In either case I am pretty sure I could revive this thing if I can re-flash with the correct firmware.

I have contacted support and opened a case but everything they suggested does not work and when I ask them if I can re-flash the STMLINKV3 MCU using another method, they just ignore the question.  They also ignored me when I asked for an RMA.  I think I will have to keep pestering them.

Thanks for you help