Shaft Encoders, sometimes called a “rotation sensors”, measure the amount of rotation on the shaft, or axle, which passes through the its center. As the axle turns, the encoder “counts”. The shaft encoder measures 360 counts per revolution, and counts up for forward movements and down for reverse. By monitoring the axles connected to your robot’s wheels, the encoders allow you to control the overall distance the robot travels.
We’ve completed a set of tutorial videos in the VEX Cortex Video Trainer that will teach you in-depth how the encoders work, how to use feedback from the sensors to control the distance the robot travels, and how to use the ROBOTC Sensor Debug window to view those values in real-time.
To navigate to the videos, open the VEX Cortex Video Trainer, head to the Movement section, and choose Shaft Encoders. The 5 tutorial videos, along with helper documents, programming challenges, and additional resources are all available for free from that page!