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.

[Turbo J]

Your computer is unusally slow:

$ time ./nrfutil.exe --help
Usage: nrfutil.exe [OPTIONS] COMMAND [ARGS]...

[ ... ]

real    0m4.962s
user    0m0.000s
sys     0m0.031s

With everything in HDD cache:

real    0m1.440s
user    0m0.000s
sys     0m0.000s

This is on an i5-6600K@4GHz. The nrfutil program is a python compiled executable, so it has a rather slow starting sequence.

One thing to check is the virus scanner - these can delay stuff quite significantly. You want to check in task manager (or whatever monitoring tool you have if OS != windows) what the system does in these 30ish seconds.

Edit: This is just "nrfutil --help". It would be interesting to know if that was equally slow on OPs computer.

[AaronF]

Hi Turbo J,

I think there is something going on with my machine.  This is a new ASUS ROG computer work got for me when my Toshiba died.  I've noticed at least one other command line utility that interacts with COM ports (non-python based in that case) acting reeeaally slow.  Perhaps it's the anti-virus software?  I will use your tips to help investigate the issue when I get a chance.