Nucleo-L433RC-P board - difficulty with flashing and debugging

[freeflyer]

I am using the Nucleo-L433RC-P board but having difficulty flashing and debugging.  9 out of 10 times I get the following error...

STMicroelectronics ST-LINK GDB server. Version 7.11.0
Copyright (c) 2025, STMicroelectronics. All rights reserved.

Starting server with the following options:
 Persistent Mode : Disabled
 Logging Level : 1
 Listen Port Number : 61234
 Status Refresh Delay : 15s
 Verbose Mode : Disabled
 SWD Debug : Enabled
 InitWhile : Enabled

Waiting for debugger connection...
Debugger connected
Waiting for debugger connection...
Debugger connected
Waiting for debugger connection...
 -------------------------------------------------------------------
 STM32CubeProgrammer v2.20.0 
 -------------------------------------------------------------------



Log output file: C:\Users\JOHNLI~1\AppData\Local\Temp\STM32CubeProgrammer_a47444.log
ST-LINK SN : 066BFF323355373043142426
ST-LINK FW : V2J46M31
Board : NUCLEO-L433RC-P
Voltage : 3.27V
SWD freq : 4000 KHz
Connect mode: Under Reset
Reset mode : Hardware reset
Device ID : 0x435
Revision ID : Rev Z
Device name : STM32L43xxx/STM32L44xxx
Flash size : 256 KBytes
Device type : MCU
Device CPU : Cortex-M4
BL Version : 0x91



Opening and parsing file: ST-LINK_GDB_server_a47444.srec


Memory Programming ...
 File : ST-LINK_GDB_server_a47444.srec
 Size : 41.44 KB 
 Address : 0x08000000


Erasing memory corresponding to segment 0:
Erasing internal memory sectors [0 20]
Download in Progress:


File download complete
Time elapsed during download operation: 00:00:01.464



Verifying...




Error: Data mismatch found at address 0x0800A4E1 (byte = 0xC0 instead of 0x00)


Time elapsed during verifying operation: 00:00:00.277


Error: Download verification failed


Encountered Error when opening C:\ST\STM32CubeIDE_1.18.1\STM32CubeIDE\plugins\com.st.stm32cube.ide.mcu.externaltools.cubeprogrammer.win32_2.2.200.202503041107\tools\bin\STM32_Programmer_CLI.exe
Error in STM32CubeProgrammer
Shutting down...
Exit.

Methods I use to try and get it working is:

• Disabling 5V power (see setup diagram below),
• Disconnecting the USB
• Restarting STMCubeIDE
• Deleting the Debug folder
• Disconnecting other interface boards (see setup diagram below)

Then 1/10 times it will suddenly work.

This problem originally started when I tried to retarget the MCU from an STM32L433RCTxP to STM32L433RCTx.

I did this by editing the .ioc file and changing any reference of STM32L433RCTxP to STM32L433RCTx.

I have since gone back to the original MCU used on the board (i.e. STM32L433RCTxP), but having great difficulty in flashing and debugging.

I even created a new, clean project for the Nucleo-L433RC-P board, but the issue still exists.

I have other interface boards connected to the Nucleo-L433RC-P board and have tried disconnecting some of these in case they are interfering with the operation.  Sometimes it makes a difference, but other times it does not, so it could just be coincidence. 

Below is my setup...

 

 

For example, the audio amplifier is powered by the 5V SMPS, but even when the SMPS is disabled, the +3.3V from the Nucleo-L433RC-P board (which is used for I2CVDD pin and IC2 pull up resistors) seems to somehow power the amplifier (LED on and audio plays).

 

 

 

Why am I having such difficulty flashing and debugging and how to I resolve it ?

Is the Nucleo-L433RC-P board damaged or are my interface boards causing an issue ?

 

[freeflyer]

It wouldn't have anything to do with the external SMPS would it ?

A clean project for the Nucleo-L433RC-P board uses the following pin out...

 

But my project does not use the external SMPS and I have re-assigned the pins:

 

• PA4
  • Was a digital output (SMPS_EN)
  • Now an analogue output (DAC1_OUT1)
• PA5
  • Was a digital output (SMPS_V1)
  • Still a digital output (STATUS_LED)
• PA6
  • Was a digital input (SMPS_PG)
  • Still a digital input (SPI MISO)
• PA7
  • Was a digital output (SMPS_SW)
  • Still a digital output (SPI MOSI)

 

 

Could these changes have caused any damage ?

Because it still doesnt flash or debug even if I swtich to a clean project for the Nucleo-L433RC-P board 

Can the Nucleo-L433RC-P board be used without the external SMPS ?

 

[freeflyer]

I have removed JP8 on the Nucleo-L433RC-P board which disables the external SMPS.

Now I am able to flash and debug, so I am wondering whether reassigning the pins could have damaged the SMPS ?

I wont be using the SMPS on my custom PCB so wont have that issue, but could this be the cause of the problems I have been having ?

[freeflyer]

Spoke too soon :(

It stopped working again...

I have ordered a replacement board but wary that I dont want to damage it in case I damaged the original one