Jlink OB Clone?

[skoehler]

Hi guys,

has anyone purchased one of these JLink OB clones?
https://www.aliexpress.com/item/4000249803796.html
https://www.ebay.com/itm/J-OB-V2-JLINK-OB-JLINK-V8-V9-V9-3-STLINK-compatible-with-virtual-serial-port/352820813787

What excites me about those clones is that they have SWO support and a virtual COM port! That reduces the number of adapters on my desk: The sellers claim that the device is not limited to ST controllers.

JLink OB [1] is a Segger product designed for eval boards. It is the equivalent of the ST-Link on Nucleo Boards, in many ways. It seems the chinese may have cloned that.
Another theory would be, that it is an ST Link V2-1 clone but flashed with a JLink firmware. See [2] for more information. But that doesn't seem to be equivalent to the JLink OB.

The feature set is similar to the ST Link V2-1 on Nucleo boards. Those also offer a virtual COM port. But the chinese never cloned that. All clones that I can find come without a virtual COM port and seem to be based on the older V2 (without -1) design. Even the proper ST Link V2 (about 20€ at digikey) has no virtual COM port.

Obviously, these clones have severe drawbacks: the target voltage is probably fixed at 3.3V, no debugging of 1.8V targets. Also, future firmware updates may brick them.


[1] https://www.segger.com/products/debug-probes/j-link/models/j-link-ob/
[2] https://www.segger.com/products/debug-probes/j-link/models/other-j-links/st-link-on-board/

[thm_w]

Here is a smaller one with a picture of the PCB: https://www.aliexpress.com/item/32883585428.html
Looks to be essentially the same as a stlink clone.

There are some threads on here about adding the SWO and I believe com port wires to a stlink.
That or you can use a bluepill + blackmagicprobe which has similar features.

Or just try the one one you linked, less hassle and only a few $ more.

[ebclr]

If your time is worth some money V10 is much faster

https://pt.aliexpress.com/item/4000047004785.html?spm=a2g0o.productlist.0.0.466e2975CctSOT&algo_pvid=edc383e3-8be8-4f47-8d0b-a3e8fceb5a4d&algo_expid=edc383e3-8be8-4f47-8d0b-a3e8fceb5a4d-0&btsid=b54d7c15-bb74-4766-93e4-497e6d8137fc&ws_ab_test=searchweb0_0,searchweb201602_9,searchweb201603_53

[skoehler]

That link to V10 does not work.

[thm_w]

That link to V10 does not work.

It does, shorter link: https://www.aliexpress.com/item/4000047004785.html
$46 though.

[skoehler]

It does, shorter link: https://www.aliexpress.com/item/4000047004785.html
$46 though.

I get the message "A página que você procura não foi encontrada ". Is AliExpress geo-blocking me!?

[skoehler]

Here is a smaller one with a picture of the PCB: https://www.aliexpress.com/item/32883585428.html
Looks to be essentially the same as a stlink clone.

It's the same microcontroller even: STM32F103.
But the "smaller" one you linked has several disadvantages: no SWO, no virtual COM port, no RST pin

There are some threads on here about adding the SWO and I believe com port wires to a stlink.

I found a blog from 2016 where somebody added the SWO to a similar unit:
https://kiedontaa.blogspot.com/2016/11/ebay-j-link-ob-clone-swo-hacking.html

But the other disadvantages remain.

That or you can use a bluepill + blackmagicprobe which has similar features.

Or just try the one one you linked, less hassle and only a few $ more.

A while back, I turned a blue pill into an ST Link V2-1. But I have to say that I appreciate the convenience of a nice tiny device with a non-conductive case.

[ebclr]

This one  It's original and cheap

https://www.adafruit.com/product/3571

[GromBeestje]

These models I have no experience with. From the OB Series, I've got a purple one by CJMCU. Only does SWD. I haven't used it other then an initial test. Furthermore, I have two J-Link clones, a V8 (ILINKS) and a V9 (HLINK v9.43) . For both, I had to reflash them as the initial firmware was no good. The V8 seems to work perfectly fine, while the V9 seems to have some stability issues (resetting itself randomly).
I have been aware there are newer variants of the V9 clones, and even V10 clones start to appear.  I might order some to see what the Chinese are up to. Have they figured out the bootloader by now?

One thing to be aware of: These J-Link clones appear to supply 3,3 volts on the V_target pin by default. This can be disabled by opening  the device and replacing a jumper. Then it is the target voltage input just like the original JLink. CHECK THIS BEFORE CONNECTING BEFORE YOU BLOW THINGS UP.

It seems some sellers are offering "simplified" versions, from the pictures, this appears to mean "without level shifting"

-- disclaimer: educational purposes only --

[0xdeadbeef]

I's still go with the EDU which is ~50€ without VAT:
https://www.antratek.de/j-link-edu

The EDU is actually a PLUS hardware wise with just some licenses missing and a daily nag screen (but, well, there are ways around both issues).

[GromBeestje]

Those nag screens only work on Windows. The Linux version lacks those.

[skoehler]

I's still go with the EDU which is ~50€ without VAT:
https://www.antratek.de/j-link-edu

For a professional project? of course! Unlike the clones, they offer JTAG, are compatible with different target voltages, and are probably much more reliable. They also have SWD+SWO support. But the virtual COM port is missing. That's a big missed opportunity. If a UART including level shifting was included, I would have a UART to connect to 1.8V targets, for example. I really miss that.

[skoehler]

Here's an unexpected find:
https://www.aliexpress.com/item/32564971415.html

DAPLink seems to be an open source design!

[GromBeestje]

I's still go with the EDU which is ~50€ without VAT:
https://www.antratek.de/j-link-edu

For a professional project? of course! Unlike the clones, they offer JTAG, are compatible with different target voltages, and are probably much more reliable. They also have SWD+SWO support. But the virtual COM port is missing. That's a big missed opportunity. If a UART including level shifting was included, I would have a UART to connect to 1.8V targets, for example. I really miss that.

The J-Link EDU has VCOM ( https://www.segger.com/products/debug-probes/j-link/models/j-link-edu/ )
The J-Link EDU Mini is the one that doesn't, and it lacks level shifting too, but the EDU has it all.

Here's an unexpected find:
https://www.aliexpress.com/item/32564971415.html

DAPLink seems to be an open source design!

The DAPLink firmware is an open source project under an Apache license. ( https://github.com/ARMmbed/DAPLink )
The project is based on the Keil compiler, and requires a Keil license to build it. However, I don't think it would be too hard to port to gcc.
At least, take the part that speaks the CMSIS-DAP protocol, and interface that to the USB code of your favourite microcontroller.
Add some functions that control some GPIO pins, and that should be it. At least, that is my current analysis of the project,
I still want to try if I can create my own debugger in the way I just proposed.

[0xdeadbeef]

RTT and Ozone alone are more than enough to buy a J-Link.

[skoehler]

I bought the JLink OB from ebay for about USD 3.90. It arrived and I fired it up. It survived a firmware update by the official SEGGER software and it found my blue pill attached to SWD. It's based on a STM32F072C8. I have yet to test the virtual COM port.

[pablintino]

I's still go with the EDU which is ~50€ without VAT:
https://www.antratek.de/j-link-edu

The EDU is actually a PLUS hardware wise with just some licenses missing and a daily nag screen (but, well, there are ways around both issues).

Another vote for the EDU version if you are not going to make profit from it. Have been using it for 6 years as a hobbyst with multiple IDEs (Crossworks and Keil most of the times) and it has never failed or made weird things. Flashing is a bit faster than STlink v2.

[voltsandjolts]

Waking a sleeping beauty here I know...

I happened across a Hackaday article about unbricking a J-Link V9, which was interesting enough but then I noticed one of the comments was from Rolf Segger himself.

Nice, polite comment which leaves a positive impression of Segger as a company.

Please do use official J-Link products for commercial work, they are fast and very reliable

[eutectique]

Since that comment there were new developments, including closed hole in licensing of v10 and v11 probes:
https://bi-zone.medium.com/vulnerabilities-in-j-link-licensing-system-or-why-researching-device-security-matters-b3ba1f9b469a

Edit: fixed the link.

[GromBeestje]

Also an interesting read in the matter
https://uglyduck.vajn.icu/ep/archive/2019/05/Unbricking_a_SEGGER_J_Link_v9_debug_probe.html

[thm_w]

Also an interesting read in the matter
https://uglyduck.vajn.icu/ep/archive/2019/05/Unbricking_a_SEGGER_J_Link_v9_debug_probe.html

Thats the hackaday link above

Since that comment there were new developments, including closed hole in licensing of v10 and v11 probes:
https://bi-zone.medium.com/vulnerabilities-in-j-link-licensing-system-or-why-researching-device-security-matters-b3ba1f9b469a

Edit: fixed the link.

nice

Flaw 2. Partial coverage of the firmware by a digital signature makes it possible to execute arbitrary code on the device. Using this vulnerability, it is easy to run your own code that would modify the OEM string and the license set. As a demonstration, we have prepared a script that turns a J-Link EDU into a J-Link PLUS in a matter of seconds. We are not going to publish it as we don’t want to encourage piracy, but we’ll show how it works: