JLink using STM32

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RogerClark
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JLink using STM32

Post by RogerClark » Wed May 31, 2017 8:42 am

I've noticed that there seem to be some JLink compatible boards, similar to the STLink, on eBay

http://www.ebay.com/sch/i.html?_from=R4 ... 2&_sacat=0

e.g.
s-l225.jpg
s-l225.jpg (10.65 KiB) Viewed 650 times
So I bought one of these as a matter of interest, thinking that someone in China had put the Nucleo Jlink firmware onto a STLink dongle

I also ran the STLinkReflash tool on one of my Nucleo boards to convert it to a Jlink, thinking that when I plugged these two devices in, they would look the same.

However, this is not the case.

The both have different USB PID numbers, and the PC Jlink software reports them as completely different firmware versions, and also keeps showing popups when I plug in the Nucleo, saying that the software can only be used with STM products.

The Nucleo shows up as "J-Link STLink V1 Compiled Dec V.00 - dated of 2016 Dec 21 )
Where as the dongle from eBay reports as Segger J-Link ARM V7.00 - dated 2012 Aug 22

Actually, the eBay dongle orginally reported a lower software version, but I successfully upgraded it in the JLink configurator.

So it looks like perhaps segger made a version of JLink using the STM32F103C8 for a while and even still have an update binary for it on their servers.

And I presume that several chinese companies got hold of the firmware and reverse engineered the original Segger board, as there appear to be 3 completely different designs of PCB for this.

victor_pv
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Re: JLink using STM32

Post by victor_pv » Wed May 31, 2017 10:21 pm

RogerClark wrote:I've noticed that there seem to be some JLink compatible boards, similar to the STLink, on eBay

http://www.ebay.com/sch/i.html?_from=R4 ... 2&_sacat=0

e.g.

s-l225.jpg

So I bought one of these as a matter of interest, thinking that someone in China had put the Nucleo Jlink firmware onto a STLink dongle

I also ran the STLinkReflash tool on one of my Nucleo boards to convert it to a Jlink, thinking that when I plugged these two devices in, they would look the same.

However, this is not the case.

The both have different USB PID numbers, and the PC Jlink software reports them as completely different firmware versions, and also keeps showing popups when I plug in the Nucleo, saying that the software can only be used with STM products.

The Nucleo shows up as "J-Link STLink V1 Compiled Dec V.00 - dated of 2016 Dec 21 )
Where as the dongle from eBay reports as Segger J-Link ARM V7.00 - dated 2012 Aug 22

Actually, the eBay dongle orginally reported a lower software version, but I successfully upgraded it in the JLink configurator.

So it looks like perhaps segger made a version of JLink using the STM32F103C8 for a while and even still have an update binary for it on their servers.

And I presume that several chinese companies got hold of the firmware and reverse engineered the original Segger board, as there appear to be 3 completely different designs of PCB for this.
I think that may be a J-Link OB clone. It's like a J-link lite for onboard dev boards.
https://www.segger.com/jlink-ob.html

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RogerClark
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Re: JLink using STM32

Post by RogerClark » Wed May 31, 2017 11:48 pm

Thanks Victor

I think that must be what it is.

I searched for JLink OB and found loads of people have made their own boards using various STM32's , someone has posted the bin a F072, so I thought I'd try flashing it to a BP but it didn't work.

If I looked for long enough I will probably find the schematic for the F103C version

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RogerClark
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Re: JLink using STM32

Post by RogerClark » Thu Jun 01, 2017 5:31 am

After a bit more research I found this

https://github.com/GCY/JLINK-ARM-OB

Which seems to be firmware to run on the F103, and also the Eagle schematic and board file (though this is not quite the same as the item pictured in my previous post, it seems to be the design for a full featured JTAG device)

Just a final update...

Yes. That firmware in that repo does work.
The only thing you need to do in order to turn a Blue Pill into a JLink OB is to join PA4 to PA7 via 100 ohms. (which can actually be seen in the schematic also posted in the repo, which I also attached here)

The PA5 is SWD_CLK
PA4 is SWD_IO

Edit.
I've been informed that the firmware on github (even after being updated) does not work with the newer versions of JLink.
I tested with 6.12d and it seemed to work (but all I did was connect and read back the entire contents of a nRF51822)
Attachments
ARM-OB_STM32F103.pdf
(17.05 KiB) Downloaded 109 times

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