Hi Guys, thanks for answers. I have a better understanding now. I realize that I was trying to be too complicated. A two line out put, that could have a header on the first line, and an output on the second line sounds pretty good. To select the different outputs (real speed, scale speed, odometer, hour meter) would it be best to use a push button to rotate through the displays, or a rotary switch? Also, can the LCD's be backlit, or night visible?
I read some about Reed systems for doing a speedometer, is that a good way, or is a rotary encoder better? How does a rotary encoder work for that matter? I was thinking two of four small magnets, mounted on the axle, and some kind of counter that counts the number of times the magnets pass, and converts that into a speed value.
Thanks for your feedback.