nRF52840 stops working

[Marcio Montenegro]

Hi,
I started development using a custom board with nRF52840 QIAACO.
1. The prototype uses Holyiot-18010 module ( listed on Nordic 3rd party modules).
2. I am using supply configuration number 5 (VBUS connected to GND).
3. VDD is connected to 3.3V LDO power supply.
4. Reset key is connected to P0.18 pin.

I tested 2 projects ble_template (s140 softdevice) and blinky_systick ( no softdevice).

I can program and debug code using j-link but when I remove j-link the the cpu stops execution.
Is there any step I am missing ?

[HSh]

Hello,

Can you please let me know how did you connect the holyiot to JLink for porogramming? I directly connected SWCLK, SWDIO, V_nRF, and GND to both original Jlink Segger and nRF52840 DK. However, I am not able to programm the holyiot. Is there any trick? Do I need any pull up resistors? 

Thanks 

[Marcio Montenegro]

Yes, I did. I don't have a standalone j-link.I am using j-link from Silicon Labs EFM32 zero gecko (debug out function).

https://www.silabs.com/products/mcu/32-bit/efm32-zero-gecko

No pull up resistors.

Remember there are several GND pins : pin 1, pin 44, pin 32

Pin 55 : vnRF connect to  3.3V

Pin 47 : VBUS  connect to GND (  no USB)

Regards,

[HSh]

Thanks for your prompt reply. I will try all GND pins. BTW, I can see some components on your PCB, do I need any extra component for Jlink or USB?

[Marcio Montenegro]

 2 smd leds +  smd resistor. I used LM1117 regulator for 3,3V power supply.

2 x10uF tantalum capacitor near LM1117 and 1 100nF capacitor near vnRF pin.

circuits4you.com/.../

[HSh]

Thank you. It eventually did not work. I just connected everything as you mentioned to the nRF52840 DK, but it is not working. Thanks tough.

[Marcio Montenegro]

Hi HSh,

Check j-link pinout.I am using  the following pins:

VTref pin 1 ( connect to 3.3V),

SWIO pin 7

SWCLOCK pin 9

and any GND pin ( pin 4 to 20 )

www.segger.com/.../