FTC Programming with ElectronVolts

LineFinder uses a DoubleLineSensor and a ColorSensor to find lines of different colors. You use it by setting the color you are looking for, then calling getValue() to see if it is seeing the line color you requested.

ftc/evlib/hardware/sensors/LineFinder.java

package ftc.evlib.hardware.sensors;


import static ftc.evlib.driverstation.Telem.telemetry;

/**
 * This file was made by the electronVolts, FTC team 7393
 * Date Created: 4/10/16
 * 
 * Combines two line sensors and an LED-powered color sensor to detect the color of lines
 *
 * @see ColorSensor
 * @see DoubleLineSensor
 */
public class LineFinder implements DigitalSensor {
    public enum LineColor {
        RED,
        BLUE,
        WHITE_RED_TEAM,
        WHITE_BLUE_TEAM
    }

    private final ColorSensor colorSensor;
    private final DoubleLineSensor doubleLineSensor;
    private LineColor lookingFor = LineColor.WHITE_RED_TEAM;
    private boolean justStarted = true;


    public LineFinder(ColorSensor colorSensor, DoubleLineSensor doubleLineSensor) {
        this.colorSensor = colorSensor;
        this.doubleLineSensor = doubleLineSensor;
    }

    /**
     * start looking for a line of a certain color by turning the LEDs to a certain color
     *
     * @param lineColor the color of the line to look for
     */
    public void startLookingFor(LineColor lineColor) {
        lookingFor = lineColor;
        justStarted = true;
        if (lookingFor == LineColor.RED) {
            colorSensor.setColorBlue();
        } else if (lookingFor == LineColor.BLUE) {
            colorSensor.setColorRed();
        } else if (lookingFor == LineColor.WHITE_RED_TEAM) {
            colorSensor.setColorBlue();
        } else if (lookingFor == LineColor.WHITE_BLUE_TEAM) {
            colorSensor.setColorRed();
        }
    }

    /**
     * note: it skips the first loop because the LEDs take 1 loop to turn on
     *
     * @return true if the line of the requested color was found
     */
    @Override
    public Boolean getValue() {
        if (justStarted) {
            justStarted = false;
            telemetry.addData("Just started line finder", "");
        } else {
            if (lookingFor == LineColor.RED) {
                return doubleLineSensor.getValue() && !colorSensor.getValue();
            } else if (lookingFor == LineColor.BLUE) {
                return doubleLineSensor.getValue() && !colorSensor.getValue();
            } else if (lookingFor == LineColor.WHITE_RED_TEAM) {
                return doubleLineSensor.getValue() && colorSensor.getValue();
            } else if (lookingFor == LineColor.WHITE_BLUE_TEAM) {
                return doubleLineSensor.getValue() && colorSensor.getValue();
            }
        }
        return false;
    }

    public void act() {
        doubleLineSensor.act();
        colorSensor.act();
    }
}