Well, I got it to work now. I successfully updated my NanoVNA 1.0.45.
The problem was that I hadn't realized that after installing the DfuSe Demo software, I still needed to manually install the driver from the Windows 7 directory in the DfuSe Demo directory in Program Files. That Windows 7 driver works fine with Windows XP too.
NanoVNA App does not see the NanoVNA in DFU mode while this driver isn't installed. NanoVNA App works fine just by copying its files into a directory, but only for USING the NanoVNA, not for updating it. To update it, it does need the mentioned driver. At least in my Windows XP system. And with the old firmware I had in my NanoVNA, NanoVNA App didn't work correctly.
I think that the firmware upgrade procedure isn't sufficiently clear in the documentation. I had to work through three different documentation files, and apply some logical thinking which at my age works maybe for two hours in the morning, two days per week, to find out how to do it.
Anyway, now it works. I can use NanoVNA App just fine. I enjoy the larger number of points and the extra graph formats. I hate the slow speed that comes attached with using many points. And I wonder while the reading below 50kHz is so very unstable. It seems to be a lot better with the old software. But overall the new software is better. I probably will like it even more when I get used to it.
Gyula, I also tested NanoVNA Partner, several weeks ago, but I got the impression that it doesn't really do much more than the older program. It only shows more things at the same time, and I preferred the simpler display of NanoVNA MOD.
So, to clear things up:
There is one driver that works with NanoVNA in normal (measurement) mode, which comes in a file named stsw-stm32102.zip. This driver does NOT work in DFU mode, so it cannot be used to upgrade the NanoVNA's firmware. I had this already installed, and I don't remember whether NanoVNA MOD installed it automatically, or I did in order to use that software. Neither do I know whether NanoVNA App needs it at all. Maybe not.
And then there is another driver that's required to upgrade firmware in DFU mode. This driver comes packed with DfuSe Demo, in a file named en.stsw-stm32080.zip. After installing DfuSe Demo using the setup program in that file, one has to manually install the driver from the appropriate Win directory installed by that setup program. In a normal Windows XP installation this ends up in C:/Program Files/STMicroelectronics/Software/SfuSE v3.0.6/Bin/Driver/Win7/x86. Running the exe file in that directory will install the driver required by NanoVNA App for firmware upgrade!
It just took me a while to find out... And I hope that this post may help others who have run into the same apparent dead end.
People using newer Windows versions, maybe 64 bit ones, probably need to find out where DfuSe Demo gets installed, and need to choose the proper Win directory and file. Being old-fashioned and using just Windows XP, I can only guess that.
Manfred
