Libraries.Robots.Lego.ColorSensor

The ColorSensor class is an object representation of the LEGO Mindstorms EV3 Color Sensor.

Example Code

use Libraries.Robots.Lego.ColorSensor
use Libraries.Robots.Lego.Motor
use Libraries.Robots.Lego.Utility


class Main
    action Main
        ColorSensor colorSensor
        Motor motor
        Utility utility
        
        colorSensor:SetPort(3)                      //tells the robot that the sensor is plugged into port 2
        motor:SetSpeed("B", 540)                    //two motors to move the robot
        motor:SetSpeed("C", 540)
        motor:RotateForward("B")
        motor:RotateForward("C")
        repeat until colorSensor:GetColor() = "red"
            utility:DelayMilliseconds(20)           //interval between color checks
        end
    end
e

This action compares two object hash codes and returns an integer. The result is larger if this hash code is larger than the object passed as a parameter, smaller, or equal. In this case, -1 means smaller, 0 means equal, and 1 means larger. This action was changed in Quorum 7 to return an integer, instead of a CompareResult object, because the previous implementation was causing efficiency issues.

Example Code

Object o
        Object t
        integer result = o:Compare(t) //1 (larger), 0 (equal), or -1 (smalle

This action determines if two objects are equal based on their hash code values.

Example Code

use Libraries.Language.Object
        use Libraries.Language.Types.Text
        Object o
        Text t
        boolean result = o:Equals(

This action uses the color sensor to read the color in front of it and send back the color as a text variable. The color sensor is capable of reading 7 different colors: red, green, blue, yellow, brown, white, and black. If the color sensor is too far away from the color it is trying to read, it will return the text "none". During the measurement, the color sensor's white light will be emitted to help determine an object's color.

Example Code

use Libraries.Robots.Lego.ColorSensor

    ColorSensor colorSensor

    colorSensor:SetPort(3)
    text color = ""
    repeat while true
        color = colorSensor:GetColor()
        if color = "none"
            output "No color found."
        else
            output "Color: " + color + "."
        end
    e

This action gets the hash code for an object.

Example Code

Object o
        integer hash = o:GetHashCode

This action gets the color of light being emitted from the color sensor.

Example Code

use Libraries.Robots.Lego.ColorSensor
    use Libraries.Robots.Lego.Sound

    ColorSensor colorSensor
    Sound sound
    
    colorSensor:SetPort(3)
    text lightColor = colorSensor:GetLightColor()
    if lightColor = "red"
        sound:Beep()
    elseif lightColor = "blue"
        sound:BeepTwice()
    elseif lightColor = "white"
        sound:BeepSequenceUp()
    else
        sound:Buzz()    //the light is currently off
    e

This action uses the color sensor to measure the amount of incoming light.

Example Code

use Libraries.Robots.Lego.ColorSensor
    use Libraries.Robots.Lego.Motor

    ColorSensor colorSensor
    Motor motor
    
    colorSensor:SetPort(3)
    motor:RotateForward("B")
    motor:RotateForward("C")      //two motors used to move the robot forward
    repeat until colorSensor:GetLightLevel() > 0.15
       output "Light level: " + colorSensor:GetLightLevel()
    e

This action will provide information on the red, green, and blue levels of a measured object.

Example Code

use Libraries.Robots.Lego.ColorSensor
    use Libraries.Robots.Lego.Screen
    use Libraries.Robots.Lego.Button
    use Libraries.Containers.Array

    ColorSensor colorSensor
    Screen screen
    Button button
    
    colorSensor:SetPort(3)
    Array<number> redGreenBlueLevels = colorSensor:GetRedGreenBlueLevels()
    screen:Output("Red: " + redGreenBlueLevels:Get(0), 0)
    screen:Output("Green: " + redGreenBlueLevels:Get(1), 1)
    screen:Output("Blue: " + redGreenBlueLevels:Get(2), 2)
    button:WaitForButtonPress

This action uses the color sensor to measure the reflection of an object. It accomplishes this by projecting a red light and then measuring the intensity of that light reflected back.

Example Code

use Libraries.Robots.Lego.ColorSensor
    use Libraries.Robots.Lego.Motor
    use Libraries.Robots.Lego.Screen
    use Libraries.Robots.Lego.Utility

    ColorSensor colorSensor
    Motor motor
    Screen screen
    Utility utility
    
    colorSensor:SetPort(colorSensor:PORT_3)
    motor:RotateForward("A")  //two motors used to move the robot
    motor:RotateForward("B")
    repeat 8 times
        screen:ScrollUp("Reflectivity: " + colorSensor:GetReflectionLevel())  //displays reflectivity of object
        utility:DelayMilliseconds(500)
    e

This action is used to determine if the color sensor's light is currently on or off.

Example Code

use Libraries.Robots.Lego.ColorSensor
    use Libraries.Robots.Lego.Sound

    ColorSensor colorSensor
    Sound sound
    
    colorSensor:SetPort(3)
    if colorSensor:IsLightOn()
        colorSensor:SetLightColor(colorSensor:BLUE)
    else
        sound:Buzz()
    e

This action is used to change the color of light projecting from the color sensor. By default, the light is off. The color sensor can emit red, white, blue, or no light.

Example Code

use Libraries.Robots.Lego.ColorSensor
    use Libraries.Robots.Lego.Button
    use Libraries.Robots.Lego.Utility

    ColorSensor colorSensor
    Button button
    Utility utility
    
    colorSensor:SetPort(3)
    repeat until button:IsButtonPressed(button:ESCAPE_BUTTON)
        colorSensor:SetLightColor(colorSensor:BLUE)
        utility:DelayMilliseconds(500)
        colorSensor:SetLightColor(colorSensor:RED)
        utility:DelayMilliseconds(500)
    e

This action turns the flood light on or off entirely.

Example Code

use Libraries.Robots.Lego.ColorSensor
    use Libraries.Robots.Lego.Sound

    ColorSensor colorSensor
    Sound sound
    
    colorSensor:SetPort(3)
    colorSensor:SetLightOn(fals

This action lets the program know which port on the robot that the color sensor being used is plugged into. As such, this action must be called before any other action in the ColorSensor class will work. After calling this action, the color sensor's red light will turn on once it has fully initiated.

Example Code

use Libraries.Robots.Lego.ColorSensor

    ColorSensor colorSensor1
    ColorSensor colorSensor2
    ColorSensor colorSensor3
    
    colorSensor1:SetPort(1)                     //we can have multiple color sensors plugged into the robot at once
    colorSensor2:SetPort(2)                     //after setting the ports, we can now use any other action in the ColorSensor class
    colorSensor3:SetPort(colorSensor3:PORT_3)   //we can use a class constant to designate a port, as we