Debugging STM32f405 using Nucleo board .

[SMour.2]

Hello Team,

I debug STM32F405 on my custom PCB using nucleo board and STLink utility software.

Now, I have added a digital isolator on my PCB , and the STM32F405 MCU is powered by the isolated  3.3v supply & ground  of the isolator.

Now, the Nucleo board is connected to the PC USB supply and ground  and on other hand  onboard STM32F405 MCU is connected with the isolated power supply and ground . 

Will the nucleo board able to debug the onboard MCU with while both having different supply and ground?

[MM..1]

Different supply is possible different ground NO. Only with ISOL STLINK ST-LINK/V2-ISOL STMicroelectronics | Mouser

[SMour.2]

Hi MM..1,

Thanks for the reply. So, I can use ISOL STLINK for debugging and connect the ISOL STLINK   GND with the target MCU  GND. 

[MM..1 · Accepted solution]

Ofcourse but with ISOL you need connect GND and target 3V3 too read ISOL docu.

But for normal situation you can use Nucleo STLINK and connect GND only. But if work on other voltage base , your computer need isolate transformer then or on battery only ntb...