Error with nRF52 and Segger J-link 6-pin Header

[Cristian Alistarh]

Hi there,

I am currently working on a project where I would need to use the Segger J-link needle programmer with 6 pin header. We have produced the board and after following the forums and previous designs we tried to program the device but it would not detect the Cortex M device.

We think that it might have to do with the actual header pins which I might have not connected correctly on the board. Would you please advise on what we should do in order to correct the fault?

Another question is if there are any other connections needed or features enable to program the nRF52 (i.e. set any pins high) in order to ensure correct programming. For the design we did not consider any other pins, but we think the datasheet might say otherwise at another read.

Thank you very much.

[Hung Bui]

Hi Cristian,

Have you connected VCC to the board and to the VCC pin on the header for Jlink ? External pull down on SWCLK is not needed.

You can send us your schematic and layout and close-up photo of your set up so we can have close look.

If you are using Jlink lite, the VCC should be no less than 3.0V.

No other connection needed beside the SWD pins and VCC+GND.

[Cristian Alistarh]

Thank a lot for your answer. The problem was that it would not recognize the board , but I opened nRFGo studio and from there I tried to see the devices attached to the J-link. In principle, it said that it does not see any devices, but there was the option with the Recover button. I clicked on the nRF52 and like magic, it worked.