From my personal experience, lightning detection is always a bit iffy, especially in the budget price bracket. I've been experimenting with all sorts of lightning detection for 15+ years now, including a variety of home-brew devices.. The unit I had that worked best has long been discontinued but was made by a company called Stormwise
, although it only worked with C-G strikes. They probably have much improved options now.
If you're an electronics hobbyist like me, check out the Franklin AMS3935
chip which has got a lot of interest over the last few years. There was a Tindie project
that I was going to buy a few years back that packaged the chip nicely on a board with antenna and discrete components, but I never got around to it. Maybe there's an improved version now?
I'd be curious to hear from others who are interested in home-brew projects like this =)