Stlink clone adapter

stlink-clone-adapter

• Variants
  • Variant 1
  • Variant 2
  • Variant X
• PCB Renders
  • Variant-1
  • Variant-2
• Part list
• pyocd

Adapter board for a 2x5 0.1" (2.54mm) header to arm cortex 10-pin connector.

This is useful when connecting ST-Link v2 clones to a standard ARM 2x5 1.27mm pitch header.

Variants

I know of 2 variants of the ST-Link v2 clones, with different pinouts on the 2x5 0.1" (2.54mm) header. Different adapter boards provided for each variant.

One way to distinguish the variants; when unplugged, check for continuity on pins 3+4 or 5+6.

• pins 3+4 shorted, variant-1
• pins 5+6 shorted, variant-2

Variant 1

Older model I bought in ~2016.

From the pin 1 marker on the header on the ST-Link, pinout is as follows:

*Note that the labeling is incorrect for some pins on the etching on the case / on the silkscreen on the board. My device had the pinout for Variant-2 on the etching and just incorrect on the silkscreen markings 🤷.

Variant 2

Newer model I bought in 2020.

From the pin 1 marker on the header on the ST-Link, pinout is as follows:

Labeling appears to be correct on these devices.

Variant X

UNTESTED DESIGN

Support both pinouts with a 3x4 0.1" header to select between them.

Alternative approaches:

• digital selection (mux the 4 connectors), controlled somehow by the signals. this has the defect of additional propogation losses through the mux, and complexity in the control circuit
• provide 2 2x5 0.1" headers on the board (would be a funky looking board!). the connectors are somewhat expensive at $0.80 @ qty 1 but makes for a simpler design
• provide a single 6-pin strip (3.3v, GND, RST, SWDIO, SWCLK, SWO) and use 0.1" jumper connectors to wire it to the probe (kinda janky connection vs. single connector though).

PCB Renders

Variant-1

Variant-2

Part list

• 2x5 header
• arm 10 pin
• 2x4 shunt/jumper alternate

pyocd

Quick note about using the stlink v2 clones with pyocd; I had the best luck using the device after updating the firmware using the official ST updater:

❯ java -jar stsw-link007/AllPlatforms/STLinkUpgrade.jar -jtag_swim -force_prog
Firmware version detected: V2J29S7
................Upgrade is successful.
Version read: 2.37.7

After upating the version should report V2J37S7 if you run the updater again.

There's a ton of information out there on the stlink devices themselves (I found this helpful).

On ubuntu there's an available package stlink-tools (source) which contains some utilities and udev rules for the st-link devices. I didn't end up using the tools themselves but it could come in handy.