I'm actually thinking about building rpm meter from 0 to 80,000 rpm for my mini gas turbine jet engine, I might give it as a project to a student or might have the enjoyment of building it myself if I had the time.
I need to be able to display rpm and also use it in my closed loop feedback, do you suggest i transmit this value serially(RS-485) to the speed controller for speed feedback or what?
Mahmood