nrfutil takes 34 seconds before starting dfu

[AaronF]

I don't know why, but after issuing the nrfutil dfu command line, it takes ~34 seconds before the DFU starts and the progress bar is shown.

Sample command lines:

nrfutil dfu serial -pkg app_v0.2.1.zip -fc 0 -p COM13

nrfutil dfu usb-serial -pkg app_v0.2.1.zip -p COM30

It doesn't matter whether the interface is USB or UART.  The delay is the same.  These are signed application images transmitting to a secure bootloader.

Side note on this: Any 2-part DFU fails using nrfutil because the 34 second delay occurs again in between part 1 and part 2, but this fails because the bootloader continuation timeout is only 10 seconds.

[Dominic]

Hi AaronF

I've just come across the same issue takes about 34s to start the write. I tracked the problem down to nrfutil, it seems to only be looking for USB-UART devices that have specific vendor/product IDs:

nRF52 SDFU USB (0x1915 / 0x521f)

JLink CDC UART Port (0x1366 / 0x0105)

JLink CDC UART Port (MSD) (0x1366 / 0x1015)

But then after 34s it just lets you use the USB-UART device anyway! So pretty annoying.

I am currently using FTDI FT230, I have bypassed all the checks in the script. You can find my fork of it here:

https://github.com/illysky/pc-nrfutil - I will log an issue with them.

Hopefully this will be your issue solved as well. 

[astella]

I used files in here.

setup build and then setup install

I still have the same 30 sec delay. May I ask if those files only bypass ftdi? Is there a file that point out how to modify scripts in order to remove every check on serial port used?

Thanks

[astella]

It worked, haven't already measured times, but it is much better. Thank you, very nice insight!

1. dfu_transport_serial.py

I deleted here now

        while not device and datetime.now() - start < timedelta(seconds=self.timeout):
            time.sleep(0.5)
            device = lister.get_device(com=self.com_port)

[wslkh]

My solution:

download nrfutil source code form github:
comment out self.__ensure_bootloader() in dfu_transport_serial.py

    def open(self):
        super().open()
        try:
            # self.__ensure_bootloader()

follow the step in this link to build nrfutil and install to python distribution folder.

1. pip install -U setuptools

2. python setup.py install

And you could build your own nrfutil.exe too.