2025-10-01 8:25 PM
Hiya. This is my first time working with custom STM PCBs.
I was planning on flashing/programming my custom STM32H7 board (specifically STM32H7A3RGT6) over STLINK and then just do general purpose programming over the USB-C COM Port. However, the TAG connector pitch was the wrong size so I'll need to find an adaptor to connect that to the STLINK module I have.
I was wondering if there is anything I can do in the meantime to program the board? The SWO/SWDIO/SWDCLK pins are broken out and I have a Nucleo L432KC. Are there any guides or tutorials for me to follow for this kind of thing?
Any help is much appreciated :).
Solved! Go to Solution.
2025-10-02 2:18 AM - edited 2025-10-02 2:20 AM
@f3l1xa88077 wrote:I was wondering if there is anything I can do in the meantime to program the board? The SWO/SWDIO/SWDCLK pins are broken out
If the pins are broken out, just connect to them!
A TAGConnect is just a passive connector/adaptor - there's nothing active or special in it.
PS:
It would be worth also connecting NRST - that can get you out of some tricky situations ...
2025-10-02 1:53 AM - edited 2025-10-02 1:55 AM
Hello @f3l1xa88077 and welcome to the ST community,
The second method (not for live debug) is to use the system bootloader: AN2606 "Introduction to system memory boot mode on STM32 MCUs" / Section: 57 STM32H7A3xx/7B3xx/7B0xx devices and Table 125 that provides the interfaces/hardware available for that purpose.
2025-10-02 1:59 AM
A simple DIY custom adapter ?
You would need to check the user manual of the Nucleo L432KC, to see what jumpers / solder bridges are to change to use the onboard ST-Link for an external board.
2025-10-02 2:18 AM - edited 2025-10-02 2:20 AM
@f3l1xa88077 wrote:I was wondering if there is anything I can do in the meantime to program the board? The SWO/SWDIO/SWDCLK pins are broken out
If the pins are broken out, just connect to them!
A TAGConnect is just a passive connector/adaptor - there's nothing active or special in it.
PS:
It would be worth also connecting NRST - that can get you out of some tricky situations ...
2025-10-03 8:34 AM
Hiya. I've been able to connect my custom H7 board to my STLINK with some breadboard wires, but I'm having issues with actually connecting to the chip.
23:25:25 : ST-LINK SN : 0029003F3333511731363730
23:25:25 : V3J15M7
23:25:25 : Connected via SWD.
23:25:25 : Connection mode : Normal.
23:25:25 : Debug in Low Power mode enabled.
23:25:25 : Can not connect to the target!
23:25:26 : Unexpected error
I've tried swapping pins around to see if I connected them incorrectly, but I only get "Connected via SWD" with the proper connection.
NRST is pulled high and I have my 2.2uF caps on VCAP.
Any ideas?
2025-10-03 8:38 AM
Are you using ST-LINK utility?
Please use STM32CubeProgrammer tool instead. STLINK utility was deprecated since a while.
2025-10-03 10:19 AM
Hi. Yes, I was using STLINK utility. I've swapped over to CubeProgrammer and it all works now! Thanks.
2025-10-03 10:50 AM
Hello,
So the solution was just to swap from STLINK utility to CubeProgrammer or there is something else that you have modified on the board?
2025-10-03 10:55 AM
The solution was just using breadboard pins to connect the STLINK. The tutorial/guide I was following was a bit old so that's why I got stuck on the software.