Ken,
I used DFU File Manager to convert your hex file to dfu format and then DFU Demo (not File Manger as I previously wrote) was able to load the converted file without error. I encountered the following problems after the upgrade was complete:
1. I could not get a good touchscreen calibration no matter how many times I tried. I had to resort to using the multi-function switch to navigate the UI.
2. The NanoVNA-H4 serial port was not recognized after the upgrade, so no CLI commands could be issued to the NanoVNA-H4.
3. The center frequency problem reported in is still present in your upgrade.
I loaded hugen's January 18th, 2020 release and touchscreen calibration worked, serialport communications was restored, the center frequency issue was still present.
I suggest users hold off on the upgrade until you look into these issues, unless they are adventurous.
Herb
