Hello,
I am using an STM32WB05KZ on a custom PCB. Initially, I was able to program it normally via SWD using STM32CubeProgrammer, but after uploading a BLE Beacon example, I can no longer connect to the MCU.
CubeProgrammer now shows:
Error: Unable to get core ID
Error: ST-LINK error (DEV_TARGET_CMD_ERR)
No STM32 target found
My Hardware Setup
Custom PCB using STM32WB05KZ
SWDIO, SWCLK, RST, VDD, GND routed through through-hole pads
ST-LINK V2 firmware: V2J46M33
Operating voltage: 3.21 V
SWD frequency tested from 4 MHz down to 100 kHz
Tried Normal, Hotplug, and Under Reset modes
Tried holding RESET while connecting → no success
My Situation
After flashing the BLE firmware, SWD stopped responding completely.
It seems the firmware reconfigured the SWD pins early or put the device into DeepStop, which disables SWD access.
I saw advice suggesting to force the chip into the UART bootloader by pulling PA10 HIGH and resetting.
However, since I designed a custom PCB (not the NUCLEO-WB05KZ), I manually tie PA10 to VDD and then reset, but SWD still does not reconnect.
I have attached the PCB pinout and SWD/UART wiring for reference (in the actual forum post).
Requested Help
How can I recover the STM32WB05KZ and re-enable SWD?
Is there a recommended recovery procedure for WB devices stuck after BLE firmware or DeepStop?
Does the WB05KZ support a boot pin (similar to BOOT0) to force the system bootloader?
How can I prevent future BLE examples from disabling SWD or forcing STOP mode?
Any guidance from ST engineers or community experts would be greatly appreciated.
Thank you.
See AN2606 for ways to boot up into the bootloader. Once in the bootloader, SWD will work.
If none of those are feasible, you will need to try to hit "Connect" on STM32CubeProgrammer right after power is applied and before the firmware goes into low power mode. Depending on your program, this may or may not be possible.
Those are the only options.
