Brand: VEX Robotics
Product Code: 276-2156
Availability: In Stock

With the Quadrature Encoder's two output channels you can measure both the position and direction of rotation of a VEX shaft. This will allow you to calculate the speed of the shaft, as well as the distance it has traveled; these are very useful measurements for autonomous programming. A Programming Kit is needed to change the program in the VEX Controller to use the Quadrature Encoder.

  • Measure Angular Travel.
  • Determine Rotational Direction.
  • Calculate Shaft Speed.
  • Calculate Distance Traveled.
  • Increase Navigational Control.
  • More Autonomous Functionality.


Function: The optical shaft encoder is used to measure both relative position of and rotational distance traveled by a shaft. It works by shining light onto the edge of a disk outfitted with evenly spaced slits around the circumference. As the disk spins, light passes through the slits and is blocked by the opaque spaces between the slits. The encoder then detects how many slits have had light shine through, and in which direction the disk is spinning.

Applications: The optical shaft encoder can be used to track distance traveled, direction of motion, or position of any rotary component, such as a gripper arm.

Technical Specifications

Kit Contents
  • (2)Optical Shaft Quadrature Encoder
Downloads & Docs Documentation
Instruction Sheet - Optical Shaft Encoder
Compatibility All VEX Microcontrollers.
3-Wire Extension Cables.
  • Type:Mechanical rotation
  • Rotation:Continuous
  • Size:Standard VEX 1/8in shaft
Outputs 3-Wire Cable
Connect to two interrupt inputs.
  • Black:ground
  • Red:+5V
  • White:control signal
  • Sensor:Infrared light sensor and infrared LED, Encoder Wheel has 90 slits
  • Cortex Resolution:360 ticks per revolution
  • PIC Resolution:90 ticks per revolution with easyC and easyC PRO
  •  360 ticks per revolution, incrementing by 2 with ROBOTC
  • Optical Shaft Quadrature Encoder0.078 lbs (35.4 grams)
      Actual weight one one item (no packaging)