Send and display average elevation

[relrod]

[kg4sgp]

Average elevation may not be the best to send (unless it's a short moving average of only the last few points). Why not show the last known elevation though?

[relrod]

Yeah it would be a sliding average. I want to make a nicer text UI that shows a bunch of raw data in a pretty-ish format, I think (or maybe I just want to play with ncurses because I haven't really ever done anything with it before), and this would perhaps be a better thing to go in that.

[relrod]

Refs #11.