nRF52840 not detected by J-Link

[ThilinaShehan]

Hi,

I'm trying to implement a circuit using a brand new nRF52840 chip. The chip has no bootloader included yet. When I try to burn bootloader, the chip is not detected by JLink nor USB. All the examples I have found were based on DK board and I need to know the procedure for a brand new IC.

* Circuit configuration no. 3 (7.3.3) was used as mentioned in datasheet. 3.1V supplied to VDD using external regulator. VDDH connected to VDD. USB 5V is also connected to VBUS.

* Jlink (SWDIO and SWDCLK pins) was able to identify a old IC when press Reset twice. But not the  new IC. When reset pressed twice, old IC shows in the PC storage. But new IC shows no response on PC either (not even a COM port).

Very appreciated if someone shows the steps to enter DFU mode on a "new" nRF52840 using JLink programmer.

Thank you.

[JONATHAN LL]

Hi,

Are you using a dedicated J-Link debugger\programmer?

How is the custom board power? 

What is the voltage you measure at VDD_nRF?





All you should need is VDD, GND, SWDIO and SWDCLK to be able to program the new IC.


I can review the schematic and HW layout if you want. It is something we do so you can share the files here. If you don't want it to be public then you can create a new private ticket and name it nRF52840 review.  

Regards,
Jonathan

[ThilinaShehan]

Thank you very much for the support. Problem solved when try on a different computer.