I have been unable to upgrade the firmware on my NanoVNA on Windows. Every approach I try ends up with the DFU tool claiming that the file I'm trying to program is the wrong format. I pointed to several different .dfu files, and also tried to use the DFU file manager to read the file, with the same error. I got the same issue on two different Windows laptops, both running Windows 10. Maybe there is a driver step I'm overlooking, or that is assumed in the instructions?
However, I was able to program my NanoVNA on the first try on my Mac, using the same .dfu files.
Ralph
