ST-Link V2 on a single sided DIY PCB

I am using U-Link from Keil for my debugging purposes. Sometimes it is quite bulky. I decided to design STLink V2 on a single-sided PCB in smallest possible size. Here is how it looks:


This is preliminary preview. I will post more details after first testing.

For start here’s Comparision from ST-LINK and ST-LINKv2 (check link for great source of STM32 info).

Producing this nice module starts with this template:

stlink V2 DIY PCB CLONE – PDF for toner transfer PCB production

apter transfering to FR4 and etching, the assembly process can start. First, take a look at the schematic diagram for components. I took what I have on stock. Alternatives are possible. The design is not critical.

stlink V2 schematic

The PCB assembly drawing:

stlink v2 pcb assembly drawing

Or, even better, here is stlink v2 minidongle USB module complete documentation in a single PDF file.

Now, the assembly can finally start.

a01-stlik pcb without components

First solder USB connector and LED with resistor to check if 5V is OK:

a02 - stlink v2 USB connected

The LED should turn ON:

a03-stlink v2 check supply 5V

Place the 3V3 regulator and check the supply voltage:

a04 - stlink check 3v3 3.3v

Now is the critical moment. Pick the brain donor from your favorite discovery or nucleo family of boards. I took one old discovery F4, which lived in better times. I replaced the STLINK with 20 pin header to connect directly on U-Link. The Mini USB connector was missing and didn’t know if the STM32F103 was OK or not (it was).

a05 - stlinkv2 select discovery board

Here’s the patient, the brain donor:

a06 - stlinkv2 discovery board brain donor

Now it’s time to heat up some air:

a07 - stlinkv2 heat up some air

And remove the STM32F103 from the discovery board:

a08 - stlink v2 heit the brain

It took just few minutes and the microcontroller was removed:

a09 - stlink v2 brain desoldered

After placing all components, the PCB looks great. It took me one evening from bare FR4 to complete assembled module:

a0a - stlink v2 finally assembled usb mini dongle


And finally…… I started nice little application called USBDevView and crossed my fingers:

Yeeaaahhh, the brain surgery was success.

I can now start debugging wit my little old/new miniature STLINK V2 USB dongle.

Thank you for reading this post!



  1. Peter says:

    Board looks great. How did you preserve 90 ohm USB differential pair on data ports with single sided PCB? And where will you get STLink V2 binaries? Is firmware publicly available?

  2. Mare says:

    Here are instructions how to program blank STM32 with STLink firmware>>>

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