Distance Sensors

What is a Distance Sensor?

A distance sensor measures how far an object is from the robot. FTC teams commonly use Time of Flight (ToF) sensors, which determine distance by measuring how long it takes light to bounce back from an object.

These sensors are fast, accurate, and easy to integrate into autonomous routines.

Common Distance Sensors

• REV 2m Distance Sensor
• goBILDA Distance Sensor
• Other compatible I2C ToF sensors

Common Uses

• Wall alignment
• Automatic parking
• Detecting game pieces
• Aligning with scoring locations
• Detecting obstacles

Connecting the Sensor

Most distance sensors connect through an I2C port on the Control Hub or Expansion Hub.

Reading Distance

The FTC SDK returns measurements in several units.

DistanceSensor sensor = hardwareMap.get(DistanceSensor.class, "distance");

double inches = sensor.getDistance(DistanceUnit.INCH);
double centimeters = sensor.getDistance(DistanceUnit.CM);

Available units include:

• Inches
• Centimeters
• Millimeters
• Meters

Example

if (sensor.getDistance(DistanceUnit.INCH) < 5) {
    intake.stop();
}

This example stops an intake when an object is within five inches.

Things to Keep in Mind

Distance sensors work best when:

• The object is directly in front of the sensor.
• The target has a solid surface.
• The sensor is mounted securely.

Performance may decrease on reflective, transparent, or very dark surfaces.

Best Practices

• Mount the sensor so it has a clear view.
• Avoid blocking the sensor with robot parts.
• Filter noisy readings if needed.
• Always check for invalid readings.