"Can I upgrade the firmware and obtain additional functionality?"
Yes. You didn't say how old your NanoVNA is, or its firmware version - but, if you carefully make note of its current version, find, download and save that version, then you can install any newer version. Test any new ones, then, and you can still go back and re-install your current version.
If your current one is more than a year old, there will be many new features in newer versions.
You can 'swap around' firmware versions sort of like you can swap pairs of socks. Well, it will be harder the first time.
There's an old "AA" version that's nice for use testing antennas outdoors - it has an extra-large text font for much easier readability in brighter light. The "AA" seems to be for "Antenna Analyzer".
Be sure to read up about changing firmware, and maybe also watch some videos about doing it. The first time or two will seem a little tricky or difficult, but that's mostly just because it's something new (to you).
Good luck, and have even more fun with your Nano!
--
Doug, K8RFT
