How to do firmware update on nRF52840 through usb (not the usb with J-link)?

[cpeng]

I was checking DFU through serial usb/uart on the following link:

https://infocenter.nordicsemi.com/index.jsp?topic=%2Fsdk_nrf5_v16.0.0%2Fsdk_app_serial_dfu_bootloader.html

I want to double check if this entire project is for programming the nordic chip through the usb port on the long side (not the one on the short side with J-link) on nFR52840 DK.

I'd like to get a confirmation from any dev who knows about this.

And if it's yes, then it gets where it confuses me:

Do I need to build and run this project onto the DK through J-link first? 

These commands mentioned in above page: 

nrfutil dfu serial -pkg package.zip -p COM_PORT for UART transport
nrfutil dfu usb_serial -pkg package.zip -p COM_PORT for USB transport

Do they go through the usb port on the long side  (not the one on the short side with J-link)?

Does that mean I need to connect a second usb cable from pc to DK usb long side?

[Amanda Hsieh]

Hi, 

I want to double check if this entire project is for programming the nordic chip through the usb port on the long side (not the one on the short side with J-link) on nFR52840 DK.

No, you need to USB connector J2 for the interface MCU. 

 

Do I need to build and run this project onto the DK through J-link first? 

 Yes. 

 

Does that mean I need to connect a second usb cable from pc to DK usb long side?

 If you don't debug, you can move the USB cable to J3 after loading the DFU bootloader image. Then, you will see SDFU USB under the Ports in the Device Manager window. 

-Amanda H.