Welcooome man...
Well... if you want to use gear tooth sensor, you must to know PID controls.
PID controls is a method that controls the movement of your robot.
But...
Basically, the gear tooth sensor is a pulse counter.
You should to use near any screw.
Example: the robot wheel's have 10 screws... when it turned, the gear tooth will count the screws and return 10 pulses in digital input of FRC...
10 screws = 1 turn of the whell = 2*3.1415*R_wheel
You'll know that ten screws corresponding to 'x' feet displacement of your robot, so you should to do a simple operation:
10 screws = 1 feet (Example)
'x' screws = 5 feet
When you find the quantity of screws, you'll set as your set point on your program....
gear_tooth_sensor = set_point - rc_dig_in0x
when 'gear_tooth_sensor' = 0, your bot will stop.
To get counter, you need set a
interruption on FRC, and... the conection wires is: Signal - 5V - GND...
Our autonomous in last year:
http://www.youtube.com/watch?v=0_NWM2OEfI0 ( gear tooth + gyro + CMU cam + sensor magnatic to detected Spider lag)
I try to explain, but my english isn't so good..
Good luck for your team!!!!