3
\$\begingroup\$

I have a STM32F103C8T6 (aka blue pill) and worked with it.

Sometimes - due a reason I don't understand - after debugging it (using Eclipse), the connection is lost and I cannot start a new debug session.

The only thing to do is the following time consuming procedure:

  • Close Eclipse
  • Start ST-Link Utility
  • In the menu ST-LINK/Firmware Update, selecting button Device Connect (to see if the ST Link stick can connect).
  • In case of an error, reinsert it (Windows shows Unknown USB Device) and redo the previous step
  • In case of no error, it shows the version: V2.J27.S6 STM32+STM8 Debugger
  • Than on the STM32 I have to press and hold the reset button
  • Select the menu option Target/Erase Chip
  • Release the button (in time, otherwise repeating the previous step)
  • Than the chip is erased.
  • Than start Eclipse again and I can continue

This is already a very tedious operation... is there a better solution? Or by what reason the debugging session causes the STM32 to lose the ability to start a new debugging session?

And even than in some cases I get the following error when trying to debug:

23:23:02 : Can not connect to target!
                  If you're trying to connect to an STM32W1xx device, please select Normal or HotPlug mode from Target->Settings menu.
                  If you're trying to connect to a low frequency application , please select a lower SWD Frequency mode from Target->Settings menu.
23:23:03 : No target connected

The Eclipse project configuration file fragment:

# use software system reset
reset_config none
set CONNECT_UNDER_RESET 0
\$\endgroup\$
2
\$\begingroup\$

I found the problem of one of the questions, so I added it for other people's reference, since it is a non-trivial default:

When using the STM32CubeMX which I do, whenever a project is made, by default the following item is selected:

  • SYS, Debug: No Debug

This causes that the following code is generated in HAL_MspInit:

__HAL_AFIO_REMAP_REMAP_SWJ_DISABLE();

As soon as the debugger passes this command (which is one of the first commands in HAL_Init which is called in main(), the debugger loses connection and even a new debug session cannot be started.

It can be easily fixed with setting to

  • SYS, Debug: Serial Wire

(which is also called SWD: Serial Wire Debug, and is supported by ST Link 2).

This causes that the following code is generated in HAL_MspInit:

__HAL_AFIO_REMAP_SWJ_NOJTAG();

And debugging works as usual.

\$\endgroup\$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.