import lejos.nxt.*;/** * A sensor that is able to distinguish a black/dark surface * from a white/bright surface. * * Light percent values from an active light sensor and a * threshold value calculated based on a reading over a * black/dark surface and a reading over a light/bright * surface is used to make the distinction between the two * types of surfaces. * * @author Ole Caprani * @version 23.08.07 */public class ColorSensor { private RCXLightSensor ls; //private LightSensor ls; private int blackLightValue; private int whiteLightValue; private int blueLightValue; private int blackWhiteThreshold; public final int Black = 0; public final int White = 1; public final int Blue = 2; public ColorSensor(SensorPort p) { ls = new RCXLightSensor(p); // Use the light sensor as a reflection sensor //ls.setFloodlight(true); ls.activate(); } public ColorSensor(SensorPort p,int black, int white) { ls = new RCXLightSensor(p); // Use the light sensor as a reflection sensor //ls.setFloodlight(true); ls.activate(); blackLightValue = black; whiteLightValue = white; blackWhiteThreshold = (blackLightValue+whiteLightValue)/2; } public ColorSensor(SensorPort p,int black, int white, int blue) { ls = new RCXLightSensor(p); // Use the light sensor as a reflection sensor //ls.setFloodlight(true); ls.activate(); blackLightValue = black; whiteLightValue = white; blueLightValue = blue; blackWhiteThreshold = (blackLightValue+whiteLightValue)/2; } public void setColor(String color, int value) { if(color.equals("Black")) blackLightValue = value; else if(color.equals("White")) whiteLightValue = value; else if(color.equals("Blue")) blueLightValue = value; blackWhiteThreshold = (blackLightValue+whiteLightValue)/2; } public boolean black() { return (ls.readValue()< blackWhiteThreshold); } public boolean white() { return (ls.readValue()> blackWhiteThreshold); } public boolean blue() { int val = ls.readValue(); //return ( ((blueLightValue + 2) > val) && (val > (blueLightValue - 2)) ); return ( (val >= blueLightValue - 1) && (val <= blueLightValue + 1) ); } public int light() { return ls.readValue(); }}