52840 usb secure dfu

[mahaifeng]

Dear Engineer,

We are working on 52840 usb dfu,program softdevice s140_6.0,

and usb secure bootloader,

evaluate board is pca10056,v0.9.0

Led1,led3 turn on once load bootloader.

nrfutil version is 3.2.1,

in infocenter,usb dfu page,step 9 said this:

Enter the following command to start the DFU process over the serial link, where package.zip is the name of the firmware package that you want to upload and COM_PORT is the COM port to which the device is connected:
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

The problem is enter nrfutil dfu --help,

not list item usb_serial.

Tried serial instead of usb_serial,it not work.

On devzone,seems need connect rtt viewer,

my question is why need rtt viewer,it not related.

And which version 52840 solved this problem.

Thanks

Best Regards

Robert

[Bjørn Kvaale]

I am using nrfutil version 3.4.0 & when I enter the command nrfutil dfu --help, I get help information for the usb_serial command. Could you try upgrading to the latest nrfutil version & testing again?