The rotation sensor is a sensor that measures the rotation of an axle. As the axle turns, the rotation sensor counts how much the axle rotates. There are 16 counts in 1 complete revolution of the axle. The number of counts is what the RCX reads as input.

When the axle stops rotating, the rotation sensor stops counting. If the axle starts to rotate again, the rotation sensor begins counting where it left off. If the axle rotates in the opposite direction, the rotation sensor counts backward. It is important to reset the rotation sensor at the start of your program.

Rotation sensors are very useful to measure and control how far your robot moves. By measuring how many times your robot's wheels turn, and knowing the circumference of the wheels, you can measure how far your robot has moved. You can also use a rotation sensor to measure rotational speed. If you count how many revolutions an axle makes in a certain amount of time, then you can use this to calculate the number of rotations per second of the axle.

If a rotation sensor has 16 counts in 1 revolution, how many degrees does the axle turn for 1 count of the rotation sensor? Click here for the answer.

See also: Sensors, Programming: Rotation sensor, Servo Motor