Loose connection to the STM32 of a hoverboard after a first launch of an empty program

[QRich.1]

Hi,

I try to flash an hoverboard MCU but after the first launch, it is impossible to connect again to the MCU. It is like it was damaged :'(

Steps:

• I put the board under battery
• I connect the ST-Link to the 4 pin
• I connect the ST-Link to the usb
• I Connect with ST-Link Utility -> It works !
• I Create an empty project in STM32CubeIDE with the correct .ld
• I build and run
• I loose the connection forever, even on the IDE or the Utility

The MCU is a STM32F103RCT6 the project is configured with stm32f103rctx_flash.ld

It is the second board I fail, I am totally stuck.

Thanks for any help

[TDK]

Are you reassigning the SWDIO/SWDCLK pins? This will prevent ST-Link from being able to connect when your program is running.

If you hold the chip in reset (NRST low), it should be possible to connect with ST-Link.

[Tesla DeLorean]

Pulling BOOT0 HIGH will block flash code running, allowing you to recover.

Check your build for entering low power mode, or actively supressing/disabling the debug pins.

[QRich.1]

Victory !!

I succeed to connect to my board in the mode "Connect under target" with putting NRST to low and high.

I erase the memory and now I could connect in mode "Normal".

I guess it was the call to the function __HAL_AFIO_REMAP_SWJ_DISABLE() in HAL_MspInit() but why call this function in the blank program of STM32CubeIDE ?

Thanks a lot