2026-01-13 2:50 AM - last edited on 2026-01-13 3:16 AM by Andrew Neil
I developped my own PCB based on STM32L051K8U6 MCU and manufactured by JLCBCP. I'm using EasyEDA.
At first I used a ST-LINK V2 ( probably a clone) to flash my card with CubeIDE and Cube Programmer but I got Error : Unable to get Core ID.
So I bought a ST-LINK V3 MINIE and a breakout board and I get the error.
13:50:07 : UR connection mode is defined with the HWrst reset mode
13:50:07 : ST-LINK SN : 001F002A4142501820353451
13:50:07 : ST-LINK FW : V3J16M8
13:50:07 : Board : STLINK-V3MINIE
13:50:07 : Voltage : 3.30V
13:50:07 : Error: Unable to get core ID
I think, I read all knowledge database from STM website
-I manage to use shorter dupont as possible to link breakout board to my board.
-Each VDD and VDDA pin has 100 nf découpling capacitors ( and 1 uF capacitor in parallele )
-There is a steady 3.3V on each VDD pin
- a perfect continuity beetween SW pins (SWDIO and SWCLK) from MCU side and SW pins from ST-LINK V3 MINIE side.
- NRST pin is pulled up at 3.3V and linked to ST-link RST pin.
BOOT0 is connected to GND
I don't undestand what is wrong. I tried to reflow the MCU pins but there is no change
Any idea ?
2026-01-13 3:04 AM - edited 2026-01-13 3:05 AM
Should work.
Connect st-link to board and try connect in CubeProgrammer, show what its telling.
set software reset;
ex. with st-link V2 "stick" :
2026-01-13 3:28 AM - edited 2026-01-13 4:17 AM
@Fabrice44 wrote:I developed my own PCB
Then you'll need to share the schematic & layout - we have no other way to know anything about your design!
How to write your question to maximize your chances to find a solution
Some good, clear photos would also help.
Did you carefully follow Application note AN4467, "Getting started with STM32L0xx hardware development" ?
Did you assemble the board yourself?
Are you sure that the MCU is correctly oriented on the board, and all solder joints are good?
Have you checked all other components for orientation, good soldering, etc?
I guess you now have a genuine ST-Link?
@Fabrice44 wrote:I think, I read all knowledge database from STM website
These?
How to solve connection errors when connecting and programming the STM32 target board.
How to solve debugger connection issues
@Fabrice44 wrote:-I manage to use shorter dupont as possible to link breakout board to my board.
Although short is good, so-called "dupont" leads are prone to be unreliable - a proper debug cable & connectors would definitely be preferable.
What do you mean by "breakout board" here?
Again, photos would help.
2026-01-13 3:53 AM
The log previoulsly posted is extracted from CubeProgrammer .
Below "Debug in Low power mode"
External loader is blank
Target voltage 3.29V
Firmware Version V3J16M8
Target information part is empty
2026-01-13 4:08 AM
I think a screenshot - as @AScha.3 showed - would be more useful than manually transcribing the details.
Also what version of CubeProgrammer are you using, and on what platform?
How to take screenshots in Windows
2026-01-13 4:33 AM
I think I follow the application note.
JLCPCB assembled the board and I used EasyEDA Pro to design the board. Footprint is identical to STM datasheet.
So I'm confident that MCU is correctly oriented and solder joint are good. I checked the component directly linked to MCU .
I have a genuine ST-LINK V3-MINIE and yes the knowledge databases are these you linked.
I understand tha a proper debug cable is preferable but I designed my board with a 6 pins header for debug and programming : Here is the breakout board
2026-01-13 4:38 AM - last edited on 2026-01-13 4:41 AM by Andrew Neil
Here is a screeshot . I'm using CubeProgrammer V2.21.0
2026-01-13 4:57 AM - edited 2026-01-13 4:58 AM
@Fabrice44 wrote:Footprint is identical to STM datasheet.
So I'm confident that MCU is correctly oriented
That doesn't follow: the package is square, so it will "fit" in 4 different orientations on the footprint - only one of those will work!
Again, photos would help.
@Fabrice44 wrote:I understand that a proper debug cable is preferable but I designed my board with a 6 pins header for debug and programming
So you're connecting from the STLink to this breakout, and then from the breakout to your PCB?
Plenty of scope for errors & poor connections there!
Why not just go straight from the STLink to your board?
How do you connect the STLink to breakout?
Again, photos would help.
Why not just make a cable to connect direct from the STLink to your board; eg,
2026-01-13 5:04 AM
Here is some photos
2026-01-13 5:10 AM
Thanks.
Can you get a better closeup of the STM32?