Overview of VEX IQ (2nd gen) Sensors

Sensors provide the ability for a robot to receive feedback from the environment. There are a variety of VEX IQ (2nd gen) sensors that can be used to obtain different types of input for the robot. The table below provides an overview of what each sensor can do, and examples of how it can be used in a project.

VEX IQ (2nd gen) Sensor Comparison Table

Sensor Function Example Uses

Bumper Switch

  • Tells the robot whether its bumper is pressed (sensor value of 1) or released (sensor value of 0).
  • Detecting if the robot has bumped into an object, such as a maze wall or game object
  • Triggering a robot action, when pressed or released
  • Toggling to turn on or off motors when pressed
  • Detecting other parts of the robot, such as an arm, when it presses in the bumper

Touch LED


  • Can detect capacitive touch, such as the touch of a finger.
  • Can be set to display many colors.
  • Triggering a robot action when touched
  • Starting or pausing a program when touched
  • Displaying different colors during different parts of a program, so it is easier to pinpoint code for troubleshooting

Optical Sensor


  • Detect the color of an object

  • Detect an object

  • Detect the brightness level of ambient light

  • Measure the numerical Hue Value of an object

  • White LEDs on the sensor can provide a consistent light source when detecting colors regardless of the surrounding light conditions.
  • Coding the robot to interact specifically with an item of a certain color, such as sorting cubes by color
  • Detecting whether an object is present, such as a wall or game object
  • Triggering the robot to perform a behavior when the light level is at a certain brightness
  • Understanding precisely how the Optical Sensor is detecting color in varied lighting conditions
  • Following a line 
  • Detecting whether an object is present

Distance Sensor


  • Detects if there is an object in front of it
  • Measures the distance between itself and an object
  • Determine the relative size of an object
  • Reports the velocity of an object
  • Driving forward until the sensor detects that it is a certain distance away from a wall, then stopping driving.
  • Driving forward a certain distance to pick up a game object
  • Driving away from an object or surface until it has reached a specific distance 
  • Interacting with an object that is one size and avoiding interacting with an object that is another size, such as picking up only the small balls on a Field
  • Determining the velocity of an approaching object and printing it on the Brain's screen

Additional Sensor Information

Note that the IQ (2nd gen) Brain has a built in Inertial Sensor rather than a Gyro Sensor. For detailed information on IQ (2nd gen) Sensors, see the following articles:

For more information, help, and tips, check out the many resources at VEX Professional Development Plus

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