Discovery with external CPU

[totalsam]

Posted on December 28, 2010 at 15:14

Dear all,

Thank you for reading my post. I designed a board with a stm32f101c6t6, and wanted to be able to debug it with the STM32 discovery kit.

I removed the two jumpers on CN3 and connected my board to the Discovery's CN2, and wanted to connect to it with the ''STM32 ST-link utility'' software. However, this one tells ''No target''. Removing the connector plugged in CN2 and putting back the jumpers on CN3, everything works perfeclty well with the Discovery's own target microcontroller.

Did someone else try to connect the discovery to an external board ?

On my board, the nRST signal is high, and the boot0 signal is tied low.

Do someone have any hints ?

Thank you in advance for your help.

Sam

[STM32 hobbyist]

Posted on December 28, 2010 at 18:27

Hi buracci.sam;

I have already tried to connect the Discovery SWD to an external application (STM32F103) and everything worked fine.

Check once again your hardware according to section ''2.2.2 Using the ST-Link to program/debug an external STM32 application'' in UM0919. May you didn't connect GNDs together...

B.R.

STM32

[totalsam]

Posted on December 28, 2010 at 21:55

Hi !

Thanks a lot for your answer. With some investigation, I finally found that the problem was a grounding issue. I have both a USB to RS232 and the Discovery connected to the same board, and this made a ground loop.

Now it works.

Thanks and best regards,

Sam