As a team that just started integrating sensors 2 years ago, these are our first trial and errors:
For an absolute position, there are absolute encoders, but I cannot tell you where to find any. How we do absolute position is by using limit switches to reset a relative position anytime a limit switch is hit. This year we are using a gear tooth counter on our arm, because of the way we are running it, with two limit switches on either side to set the limit angles, and also prevent from over-rotating.
You will get a chance to show your students how math is used with the encoder on your toughbox, because you want to find out mathematically what your ratio will be of how fast the encoder spins to how much the angle changes (assuming you are using optical or any shaft based encoder). Try not to do it experimentally, because with encoders, the mathematical formulas are more often than not more accurate than anything you can measure. (Took us a whole season to learn that lesson).
Anything else you need I am sure all of us at Chief Delphi have answers for you.
