1

I am using STLink V3 set to program the F103RB Nucleo board using SWDIO interface. The board works fine when connected to PC using the on-board STlink debugger but when I use external STlink device to program it, it says "Can not connect to target!". I have removed on-board STlink debugger jumpers so that I can use external one. My connection from Stlink V3 to F103RB Nucleo (CN4 Header) are as follows:
Clock->Clock, GND->GND, SWDIO->SWDIO, NRST->NRST,VCC->NOT CONNECTED (Even if I connect, it doesn't work)

The datasheet says that "SB12 NRST (target MCU RESET) must be OFF if CN4 pin 5 is used in the external application", is this the problem ? How to resolve that ? or is there any other potential reason for this error.

I'll really appreciate prompt responses. Thanks

Clifford
  • 88,407
  • 13
  • 85
  • 165
No Man
  • 113
  • 6
  • This is not the place for this question - it is not an issue with your code. The the appropriate stack exchange site would be https://electronics.stackexchange.com/ – Clifford May 28 '21 at 12:51

1 Answers1

2

CN4 connector is connected to on-board ST-LINK, which is used when you use on-board ST-LINK to program/debug an external device.

You need to access pins of the main uC using other connectors.

Please see this answer: https://electronics.stackexchange.com/questions/566511/how-can-i-program-a-stm32-nucleo-board-without-using-the-on-board-st-link/566515#566515

Tagli
  • 2,412
  • 2
  • 11
  • 14
  • Thank you. It worked for me. I was mixing that on-board debugger with the external one. Thanks for prompt response – No Man May 28 '21 at 13:04
  • 1
    @Noman Then please mark this answer as the *accepted answer* by clicking on the *check* button on the left of the answer. – Tagli May 28 '21 at 13:08