DFU - what is "Init packet file" (*.dat) and how to get it?

[Jarmo]

I now have my app.hex and bootloader is running at nRF51822 and yet, the nRF Toolbox finds "DfuTarg" as expected. However, after selecting my file the UI surprisingly starts to ask about "Init packet" and I just say "NO", because I don't have such a thing anywhere.

Yep, right, the device firmware upload fails after that! Great. Two times it complained about missing init data or something, and two times the error was something else.

So, how to get that stupid .dat file there? And sorry, I am a bit frustrated after yet another fruitless day... complains removed

[Wojtek]

How to generate the INIT file for DFU?

Use method with nrfutility, as it is the most simple one.

[Jarmo]

I got it working by adding 0x64 code in the list of --sd-req in the nrfutil command line. That code is for the 8.0 S110 soft device, it was mentioned in another thread. But there's now another issue, my DFU enabled application doesn't enter bootloader correctly. It might be similar thing you mentioned. I initiated a new discussion thread for that. Thanks for support this far!