[GeeTwo]

Sensor #1 for us is going to be the streaming camera located a few inches below peg level (so it doesn't get impaled). We will probably also have a rear streaming camera (though we only stream one at a time) for gear intakes, and a front camera to detect the vision guides for autonomous. There are also teams which use cameras to automatically find game pieces and goals. Edit: for streaming drive video, do low resolution, relatively high frame rate feed. For targeting taking place on the robot, use a bit higher resolution even if it means slower frames, and (assuming you're talking about a light ring and retroreflective tape) short exposure times. For teleop, some teams have used their drive camera, and marked the "best" location of the retroreflective tape on their laptops, either digitally through the drive station code, or by putting strips of painter's tape on the screen.

Short-range rangefinders (on a budget, I recommend infrared for ranges up to about a foot, ultrasonic at longer ranges) may be good this year, to let you know if you've got a bunch of balls between you and the wall with which you're trying to retrieve or score game pieces. Inexpensive rangefinders are available in both analog (voltage is a function of range) and digital (yes, something's there!) versions.

Encoders on wheels will improve the repeatability of autonomous driving for any drive train; many consider them essential for more advanced drive trains.

Another sensor type to consider for gear management are some IR or light-based interrupts to let us know when we've got the peg through the gear, and whether the gear is inside or clear of the robot, etc.