Can not connect to device

[kent gu]

Posted on October 24, 2017 at 08:53

Hi,

I use ST-Link V2 eumlator and STM32 ST-Link Utility SW to flash STM32F103VE. At the beginning, it can flash for several days. Today it can connect to device(show device information), but can't flash. It show can not connect to device.

Best Regards,

Kent

[Brieuc Delbart]

Posted on October 24, 2017 at 13:02

I have the same problem with my STM32f103. I can only connect with the 'Hot Plug' mode but by this way it's impossible to program it.

With the normal mode, it appears a pop up message 'Can not connect to target! Please select 'Connect Under Reset' mode from Target....' but nothing work !

[Brieuc Delbart]

Posted on October 25, 2017 at 09:20

I've found a solution for my problem, maybe it can help you.

https://www.waveshare.com/img/devkit/general/connector-layout-20pin_hjpg

You have to put PIN 1 and PIN 19 at the same voltage (for me 3,3V) and be sure that your JTAG Reset is well at PIN 15 and not PIN 3.

Best regards,

Brieuc

[Tesla DeLorean]

Posted on October 25, 2017 at 14:38

The external ST-LINK has buffers which must be powered by pin 1 (VTarget). Ideally this should be the board/chip voltage, which doesn't have to be 3.3V

[kent gu]

Posted on October 26, 2017 at 02:24

May my problem is not with you, I found the Vcc 3.3V of the emulator conflict with Vcc

3.3V 

of the board. I cut the Vcc 3.3V from the emulator. It works well.

Best Regards,

Kent