nRFStudio can not connect to J-Link

RE: nRFStudio can not connect to J-Link

aileen — Fri, 24 Apr 2015 03:21:20 GMT

After I removed the external 12k resistor and used the slow clock frequency, the board can connect to J-Link. Then I loaded the S110 and application to board, it works now. I will check why the high clock frequency does not work, maybe it is another question, so I close this issue. Thanks everyone.

RE: nRFStudio can not connect to J-Link

aileen — Thu, 23 Apr 2015 04:53:24 GMT

I tried the clock frequency and the maximal normal clock is 37KHz, I think maybe the external 16M oscillator does not work, I will check it.

RE: nRFStudio can not connect to J-Link

RK — Thu, 23 Apr 2015 03:40:58 GMT

Unlikely anything to do with the 16MHz oscillator. JLink tries to connect with a default speed, if it fails it tries at the slowest speed which is 4KHz. You can specify the speed with another command line

-speed 100

for instance selects 100KHz. You can try different speeds to see what you can connect with.

I would think if JLink can't connect at a good speed then you have some board problems, stray capacitance on the SWD lines, not really sure, not my area of expertise.

RE: nRFStudio can not connect to J-Link

aileen — Thu, 23 Apr 2015 03:09:07 GMT

Thanks very much, it works now. But there is a new question, the J-Link can just use the slow clock, please see the new picture, maybe the layout has something wrong? This design just uses one 16M oscillator.

RE: nRFStudio can not connect to J-Link

RK — Thu, 23 Apr 2015 02:46:50 GMT

in the latest picture you posted it seems JLink hasn't been told what kind of board and what interface to look on, which means it doesn't send the right sequence to the nrf51 and may not connect.

Why not try from the command line after closing nrfStudio (so it releases the segger).

cd c:\Program Files (x86)\SEGGER\JLink_V498b
.\JLink.exe -if swd -device nrf51

You may have to change the path if your JLink software is somewhere else, that's where it is on my windows emulator. If that doesn't work with a powered, operational board, I'd go back and check the pins and connections all over again.

RE: nRFStudio can not connect to J-Link

aileen — Thu, 23 Apr 2015 02:22:07 GMT

Thanks. I tried a new board but there is no difference. I have removed the 12k resistor and try to power on with 3.3v, still can not work. It's very strange, any ideas? P.S. I'm not sure if the J-Link is Lite version and I post a new picture, please check it.

RE: nRFStudio can not connect to J-Link

RK — Wed, 22 Apr 2015 01:59:48 GMT

Can you try powering the board from a 3.0 or 3.3v supply instead of the battery and see if it makes a difference?

RE: nRFStudio can not connect to J-Link

aileen — Wed, 22 Apr 2015 01:52:56 GMT

Hi, it is still not work after I remove the external 12k resistor, what's a pity. Because the J-Link can not scan the chip, the recover instructions are not available. I will use a new board to do some test today and will update status later. By the way, my J-Link is SEGGER OEM and I have already updated it to the latest version. Thanks.

RE: nRFStudio can not connect to J-Link

RK — Wed, 22 Apr 2015 01:51:17 GMT

What exact model of JLink do you have? The screenshot says JLink ARM but I never know if it shows the difference between ARM and ARM Lite and others. I think the ARM Lite needs 3v to work but the full JLink ARM, which I've never seen, works down to 1.8.

RE: nRFStudio can not connect to J-Link

MartinBL — Tue, 21 Apr 2015 07:40:05 GMT

Hi. As stated in the PAN document the nRF51822 QFAAG2 is not affected by the missing pull down and you should try to remove your external 12k resistor. You can also try to recover the J-Link following theses instructions. What kind of J-Link are you using?

RE: nRFStudio can not connect to J-Link

aileen — Tue, 21 Apr 2015 01:26:12 GMT

Thanks Martin, I have post the sch. The target have powered on using a cell battery and I checked the VCC already. The version is nRF51822 QFAAG2 and there is a 12k pull down resistor on the SWDCLK line. My J-Link can connect to a demo board normally, so maybe the driver is fine, I will update the driver of course. Thanks again.

RE: nRFStudio can not connect to J-Link

MartinBL — Mon, 20 Apr 2015 12:31:53 GMT

Do you have a power supply on your board? The debugger is not capable of supplying power.
What nRF51 version and build number do you use? Some IC revisions requires an external pull down resistor on the SWDCLK line. See the Product anomaly document to find out which IC revisions are affected by this.
Are you absolutely sure that you have connected everything correctly? If you want us to have a look at your design feel free to contact us at our support portal at nordicsemi.com. (Or you can post your design here if you are comfortable with that)
Your J-Link driver seems to be somewhat outdated. Try to install the latest drivers: www.segger.com/jlink-software.html. You should also download the latest version of nRFgo Studio if you haven't already.