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Ultrasonic Range Finder

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Ultrasonic Range Finder


Avoid obstacles and measure distances with the ultrasonic range finder. Device emits a high-frequency sound wave that alerts the robot to things in its path. A Programming Kit is needed to change the program in the VEX Controller.

  • Measure distances from 1.5in to 115in
  • Detect obstacles using high frequency sound waves
  • Create more autonomous function

Availability: Ships in 2 Weeks



An ultrasonic range finder sensor enables a robot to detect obstacles in its path by utilizing the propagation of high-frequency sound waves. The sensor emits a 40kHz sound wave, which bounces off a reflective surface and returns to the sensor. Then, using the amount of time it takes for the wave to return to the sensor, the distance to the object can be computed. To increase the sensing range, the sensor can be mounted to a servo to allow it to rotate.

Unlike the bumper switch and limit switch that alert you when they have been hit, the ultrasonic range finder sensor can alert you to an obstacle in the path of the robot prior to hitting it. This can allow you time to safely navigate around obstacles.

The sensitivity of the sensor depends on the objects’ surfaces that are detected by the emitted sound waves. For example, a reflective surface may produce a different reading than a non-reflective surface. The resolution of the sensor also depends on the sound waves. However, sound waves can reflect or be absorbed and possibly not return with enough power.

  • Sensitivity: Detect a 3cm diameter pole at greater than 2m.
  • Usable Range: 3.0 centimeters - 3.0 meter / 1.5 inches - 115 inches
  • Frequency: 40 KHz
  • Resolution: 1 inch
Kit Contents
  • (1) Ultrasonic Range Finder
  • Docs & Downloads
  • Start signal to the ultrasonic sensor. Connect to a interrupt port.
  • Outputs
    3-Wire Cable Connects to a interrupt port. Echo response from the ultrasonic sensor.
  • Black: Ground
  • Red: +5V
  • Orange/Yellow: Control Signal
  • Compatibility
  • Compatible with all VEX Microcontrollers and 3-Wire Extension Cables
  • CAD Files
    Click the button next to a file to view it in your browser.