Blue Pill STM32F103C8T6 not detected via ST-Link – connection/programming issue

[DanielDSouza]

Hello everyone,

I’m working with an STM32F103C8T6 (Blue Pill) development board and facing an issue while trying to program/debug the MCU using ST-Link V2.

Board used:
https://robocraze.com/products/stm32f103c8t6-arm-development-board

Issue details:

STM32CubeProgrammer / STM32CubeIDE does not consistently detect the target

Sometimes shows “No target connected” or fails during connection

Tried SWD mode with NRST connected

BOOT0 is set to 0 (Flash mode)

Power supplied via USB (5V) and also tested with external 3.3V

Checked SWDIO, SWCLK, GND continuity

I’m not sure if this is related to board configuration, clock settings, or ST-Link connection parameters. I’d appreciate guidance on:

Recommended ST-Link connection settings for STM32F103C8T6

Any known issues with Blue Pill boards (pull-ups, reset circuit, USB power, etc.)

Whether enabling connect under reset is mandatory for this MCU

I’m still getting familiar with the forum and STM32 ecosystem, so apologies if I’ve missed something obvious. Looking forward to learning from the community and thanks in advance for any help.

[mƎALLEm]

Hello @DanielDSouza and welcome to the ST community,

Please bear in mind that STM32F103 blue Pill most probably contains a counterfeit chip.

Also, you need to check your STLINK. It could be not a genuine product:

How to recognize a genuine ST-LINK/V2 versus a cloned one

[mfgkw]

Hi Daniel,

Welcome here!

The known issue with blue pill is that nearly all of them (or really all?) are faked meanwhile and are not equipped with an original STM MCU.

Use a more reputable board from a more trustworthy dealer than Ali* or temu or something like that. You probably have more fun with NUCLEO board or something like that.

Don't waste your time...

 

[Andrew Neil]

As the others have said, Blue Pill is not an ST product, and most likely does not contain a genuine STM32.

Therefore it (probably) is not supported by STM32CubeIDE - see:

https://community.st.com/t5/others-hardware-and-software/stm32programmer-is-not-connecting-with-blue-pill-device/m-p/874208#M33304

 

You will find many, many threads here with people suffering issues due to using Blue Pills; eg,

• https://community.st.com/t5/others-hardware-and-software/configuring-uart-on-stm32f103c8t6-bluepill-kills-connection-to/m-p/668641/highlight/true#M32234 
• https://community.st.com/t5/stm32-mcus-boards-and-hardware/error-in-initializing-st-link-device-reason-18-could-not-verify/m-p/314096#:~:text=It%20was%20100%25%20due%20to%20there%20being%20a%20counterfeit%20chip%20on%20my%20blue%20pill%20board

 

Do yourself a favour and at least start on a genuine ST board - such as a Nucleo-F103RB.

That way you get:

• Known-good hardware, with a genuine STM32F103
• A genuine ST-Link, all connected and ready to go
• Support
• Documentation
• Loads of ready-to-go examples
• etc, etc

That will let you get familiar with the tools and the product in a reliable, supported environment.

After that, armed with that understanding &experience, you will be better equipped to venture into the "Wild West" of Blue Pill land...

 

PS:

Here's a tool to identify what chip you do actually have:

https://mecrisp-stellaris-folkdoc.sourceforge.io/bluepill-diags-v1.640.html#diags-1-640

 

See also: https://hackaday.com/2021/06/23/test-your-blue-pill-board-for-a-genuine-stm32f103c8-mcu/

And: https://hackaday.com/2020/10/22/stm32-clones-the-good-the-bad-and-the-ugly/ 

And: https://github.com/keirf/Greaseweazle/wiki/STM32-Fakes#rogues-gallery

 

#BluePillFakeSTM32

[gbm]

Try connecting with BOOT0 set to 1. If it doesn't connect - it's very likely the chip is not 100% STM32F103 compatible.

[mƎALLEm]

Hello @DanielDSouza 

Could you please state on this thread please? did you find a solution for the described issue? if yes, could you please share it with us? 

Otherwise, we (as administrators) we will accept one of the posts listed above as a solution .

Thank you for your understanding.

[Errata26]

f your programmer connects sometimes but fails repeatedly after you upload code, your code might have disabled the debug pins.

• Connect Under Reset: This forces the ST-LINK to hold the microcontroller in a reset state before it can execute any problematic code, allowing programming lines to take control.
  • In CubeIDE: Go to Run > Debug Configurations > Debugger tab. Set the Reset Behavior to Connect under reset.
  • In CubeProgrammer: On the right-hand connection panel, change the Reset Mode to Connect Under Reset or Hardware Reset.
• see No STM32 target found | Community

[sknupf]

I also had the problem of debugging some Blue Pills while others were working with exactly the same environment and code. The problem is most likely caused by the use of cheap ST clones on these boards.

Yesterday, I encountered another problem. I’ve written a VCP software for the Blue Pill, which had already been successfully tested. I programmed it onto a new Blue Pill with an STM32F103C8T6 MCU, but the USB was not working.

I used the old ST-Link Utility, which shows the flash size of the connected MCU. It reported 128 KB, but the correct flash size for the C8T6 is 64 KB. So I’m almost certain that I have another Blue Pill with a clone MCU.

I want to share this information in case someone else runs into the same problem.

Here are my logs for the two MCUs. The only difference is the reported flash size.

Blue Pill with original ST controller:

20:46:25 : ST-LINK SN : 52FF6B064980515743161687
20:46:25 : V2J48S7
20:46:25 : Connected via SWD.
20:46:25 : SWD Frequency = 4.0 MHz.
20:46:25 : Connection mode : Normal.
20:46:25 : Debug in Low Power mode enabled.
20:46:26 : Device ID:0x410
20:46:26 : Device flash Size : 64KBytes
20:46:26 : Device family :STM32F10xx Medium-density

Blue Pill with clone MCU:

20:47:22 : ST-LINK SN : 52FF6B064980515743161687
20:47:22 : V2J48S7
20:47:22 : Connected via SWD.
20:47:22 : SWD Frequency = 4.0 MHz.
20:47:22 : Connection mode : Normal.
20:47:22 : Debug in Low Power mode enabled.
20:47:22 : Device ID:0x410
20:47:22 : Device flash Size : 128KBytes
20:47:22 : Device family :STM32F10xx Medium-density