Range Sensor Overview

The Range Sensor has many different uses and applications. These applications may include the use of the range sensor to detect the placcement on the field, or the use of the Range Sensor to track the distance from an object. A distance can then be applied to improve autonomous code or make programming the robot a more simple task to perform.

Ultrasonic Sensor

The ultrasonic element works by one of the transducers emitting a sound wave and the other receiving the sound wave. This reading is accurate between 5cm and approximately 255cm. Since the value returned is in units of centimeters, the return is linear.

Optical Sensor

The optical element works by emitting infrared light from on LED and receiving infrared light to the other LED. The optical value can detect objects within 15cm. As an object approaches the optical element the returned value will increase at an exponential rate.

An image of a Modern Robotics Range Sensor is shown here.

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Implementation

Since the Range Sensor combines the state and behavior of both the ultrasonic and optical distance sensor Object, one should know the implementation for the Four Wire I2C Sensor. To implement such a Opticl Distance Sensor Algorithm, in English it will look like:

package org.firstinspires.ftc.robotcontroller.external.samples;
import ...
public class RangeSensorImplementation extends LinearOpMode {
    ModernRoboticsI2cRangeSensor rangesensor;
    public void runOpMode() {
        /*
          The method will display the distance from objects.
        */
        //implementation is not shown
    }
}

Some things that should be noted:

Range Sensor Code Explanation

The Code Is Shown Here:

/* Copyright (c) 2017 FIRST. All rights reserved.
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 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
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package org.firstinspires.ftc.robotcontroller.external.samples;

import com.qualcomm.robotcore.eventloop.opmode.Disabled;
import com.qualcomm.robotcore.eventloop.opmode.LinearOpMode;
import com.qualcomm.robotcore.eventloop.opmode.TeleOp;
import com.qualcomm.robotcore.hardware.OpticalDistanceSensor;
/*
 * This is an example LinearOpMode that shows how to use
 * a Modern Robotics Optical Distance Sensor
 * It assumes that the ODS sensor is configured with a name of "sensor_ods".
 *
 * Use Android Studio to Copy this Class, and Paste it into your team's code folder with a new name.
 * Remove or comment out the @Disabled line to add this opmode to the Driver Station OpMode list
 */
@TeleOp(name = "Sensor: MR ODS", group = "Sensor")
@Disabled
public class SensorMROpticalDistance extends LinearOpMode {
  //instantiates new OpticalDistanceSensor
  OpticalDistanceSensor odsSensor;  // Hardware Device Object

  @Override
  public void runOpMode() {

    // get a reference to our Light Sensor object.
    //uses new method .get to store a certain parameter and take an OpticalDistanceSensor
    odsSensor = hardwareMap.get(OpticalDistanceSensor.class, "sensor_ods");

    // wait for the start button to be pressed.
    waitForStart();

    // while the op mode is active, loop and read the light levels.
    // Note we use opModeIsActive() as our loop condition because it is an interruptible method.
    while (opModeIsActive()) {

      // send the info back to driver station using telemetry function.
      telemetry.addData("Raw",    odsSensor.getRawLightDetected());
      telemetry.addData("Normal", odsSensor.getLightDetected());
      // gets update method from the class
      telemetry.update();
    }
  }
}

What the code does is utilize the fact that the OpMode is on, it will activate a forever loop that will scan light levels and record the dictance traveled.

As displayed by comments, a new OpticalDistanceSensor is instantiated in order to create a new OpticalDistanceSensor that will inherit the properties of a LinearOpMode. This will allow the program to inherit the proerties of LinearOpMode and will allow for DRY and very consistent procedural decomposition without having to repeat code. It would also make code more organized. Adding on, the UML class diagram would be less cluttered and methds are easily identifiable.

Related

Color Sensor

Gyro Sensor