[Joe Schornak]

Encoders are good for measuring the rotation of things that go around a bunch of times, like drive wheels. My team has used them to measure the heading of a ball shooter turret, the speed of the flywheel in the same shooter, and the height of a screw-driven elevator, among other things. We have used encoders in our drive train, but I would not say that most teams use them, as they are unnecessary unless you need to precisely calculate the position of your bot, as you would with a good autonomous program. The US Digital encoders that (I thought) come with the kit are good for most applications, and the company makes a variety of other kinds if you need something different. I haven't been the one wiring the encoders on my team, so I don't know the specifics of the wiring requirements, but the kit encoders should come with a diagram denoting which wires are power, ground, and signal, which all (if I recall correctly) plug into the digital sidecar.

If you need to measure something that won't make a full rotation or doesn't need to be particularly precise, consider using a potentiometer, which changes its resistance depending on the angle. We've used potentiometers on grabber arms and low-budget steering systems. As long as you choose the device to fit the application and don't do anything needlessly complex, you probably won't go wrong. Best of luck this season, and welcome to FRC!