All programs for lesson 2

Lesson 2 - Exercise 1/.classpath

+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.lejos.nxt.ldt.LEJOS_LIBRARY_CONTAINER/nxt"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

Lesson 2 - Exercise 1/.project

+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>Lesson 2 - Exercise 1</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.lejos.nxt.ldt.leJOSBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.lejos.nxt.ldt.leJOSNature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

Lesson 2 - Exercise 1/src/SonicSensorTest.java

+import lejos.nxt.*;
+
+/**
+ * A simple sonar sensor test program.
+ * 
+ * The sensor should be connected to port 1. In the known bugs and limitations
+ * of leJOS NXJ version alfa_03 it is mentioned that a gap of at least 300 msec
+ * is needed between calls of getDistance. This is the reason for the delay of
+ * 300 msec between sonar readings in the loop.
+ * 
+ * @author Ole Caprani
+ * @version 30.08.07
+ */
+public class SonicSensorTest {
+
+	public static void main(String[] args) throws Exception {
+
+		UltrasonicSensor us = new UltrasonicSensor(SensorPort.S1);
+
+		LCD.drawString("Ultrasonic ", 0, 0);
+		LCD.drawString("Distance(cm) ", 0, 2);
+
+		while (!Button.ESCAPE.isDown()) {
+			LCD.drawInt(us.getDistance(), 3, 13, 2);
+
+			Thread.sleep(1);
+		}
+		LCD.clear();
+		LCD.drawString("Program stopped", 0, 0);
+		Thread.sleep(2000);
+	}
+}

Lesson 2 - Exercise 4/.classpath

+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.lejos.nxt.ldt.LEJOS_LIBRARY_CONTAINER/nxt"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

Lesson 2 - Exercise 4/.project

+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>Lesson 2 - Exercise 4</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+		<buildCommand>
+			<name>org.lejos.nxt.ldt.leJOSBuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.lejos.nxt.ldt.leJOSNature</nature>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

Lesson 2 - Exercise 4/src/Car.java

+import lejos.nxt.*;
+
+/**
+ * A locomotion module with methods to drive a car with two independent motors.
+ * The left motor should be connected to port C and the right motor to port B.
+ * 
+ * @author Ole Caprani
+ * @version 17.4.08
+ */
+public class Car {
+	// Commands for the motors
+	private final static int forward = 1, backward = 2, stop = 3;
+
+	private static MotorPort leftMotor = MotorPort.C;
+	private static MotorPort rightMotor = MotorPort.B;
+
+	private Car() {
+	}
+
+	public static void stop() {
+		leftMotor.controlMotor(0, stop);
+		rightMotor.controlMotor(0, stop);
+	}
+
+	public static void forward(int leftPower, int rightPower) {
+		leftMotor.controlMotor(leftPower, forward);
+		rightMotor.controlMotor(rightPower, forward);
+	}
+
+	public static void backward(int leftPower, int rightPower) {
+		leftMotor.controlMotor(leftPower, backward);
+		rightMotor.controlMotor(rightPower, backward);
+	}
+}

Lesson 2 - Exercise 4/src/Tracker.java

+import lejos.nxt.*;
+import lejos.util.Delay;
+
+/**
+ * A LEGO 9797 car with a sonar sensor. The sonar is used to maintain the car at
+ * a constant distance to objects in front of the car.
+ * 
+ * The sonar sensor should be connected to port 1. The left motor should be
+ * connected to port C and the right motor to port B.
+ * 
+ * @author Ole Caprani
+ * @version 24.08.08
+ */
+public class Tracker extends Thread {
+
+	private boolean running;
+	private int sampleInterval = 100; // ms default value
+	private UltrasonicSensor us = new UltrasonicSensor(SensorPort.S1);
+	private final int noObject = 255;
+	private int distance, desiredDistance = 35, // cm, default value
+			power, minPower = 50, maxPower = 100; // default values
+	private float error, Pgain = 2.0f; // default value
+
+	public Tracker() {
+	}
+
+	public void go() {
+		running = true;
+		this.start();
+	}
+
+	public void stop() {
+		running = false;
+	}
+
+	public void run() {
+		while (running) {
+			distance = us.getDistance();
+
+			if (distance != noObject) {
+				error = distance - desiredDistance;
+				power = (int) (Pgain * error);
+				if (error > 0) {
+					power = Math.min(minPower + power, maxPower);
+					Car.forward(power, power);
+				} else {
+					power = Math.min(minPower + Math.abs(power), maxPower);
+					Car.backward(power, power);
+				}
+
+				Delay.msDelay(sampleInterval);
+			}
+		}
+	}
+
+	public int getDistance() {
+		return distance;
+	}
+
+	public int getPower() {
+		return power;
+	}
+
+	public int getMinPower() {
+		return minPower;
+	}
+
+	public float getPgain() {
+		return Pgain;
+	}
+
+	public void setMinPower(int minPower) {
+		this.minPower = minPower;
+	}
+
+	public void setPgain(float Pgain) {
+		this.Pgain = Pgain;
+	}
+}

Lesson 2 - Exercise 4/src/TrackerTester.java

+import lejos.nxt.*;
+import lejos.util.Delay;
+
+/**
+ * A simple main program to test the Tracker class.
+ * 
+ * @author Ole Caprani
+ * @version 02.02.15
+ */
+public class TrackerTester {
+	public static void main(String[] aArg) {
+		int distance, power;
+		Tracker tracker = new Tracker();
+
+		LCD.drawString("Tracker", 0, 0);
+		LCD.drawString("Distance: ", 0, 3);
+		LCD.drawString("Power:    ", 0, 4);
+
+		tracker.go();
+
+		while (!Button.ESCAPE.isDown()) {
+			distance = tracker.getDistance();
+			power = tracker.getPower();
+
+			LCD.drawInt(distance, 4, 10, 3);
+			LCD.drawInt(power, 4, 10, 4);
+
+			Delay.msDelay(100);
+		}
+
+		tracker.stop();
+		LCD.clear();
+		LCD.drawString("Program stopped", 0, 0);
+		Delay.msDelay(2000);
+	}
+}

Lesson 2 - Exercise 5 (PC)/.classpath

+<?xml version="1.0" encoding="UTF-8"?>
+<classpath>
+	<classpathentry kind="src" path="src"/>
+	<classpathentry kind="con" path="org.eclipse.jdt.launching.JRE_CONTAINER/org.eclipse.jdt.internal.debug.ui.launcher.StandardVMType/JavaSE-1.8"/>
+	<classpathentry kind="con" path="org.lejos.nxt.ldt.LEJOS_LIBRARY_CONTAINER/pc"/>
+	<classpathentry kind="con" path="org.lejos.nxt.ldt.LEJOS_LIBRARY_CONTAINER/nxt"/>
+	<classpathentry kind="output" path="bin"/>
+</classpath>

Lesson 2 - Exercise 5 (PC)/.project

+<?xml version="1.0" encoding="UTF-8"?>
+<projectDescription>
+	<name>Lesson 2 - Exercise 5 (PC)</name>
+	<comment></comment>
+	<projects>
+	</projects>
+	<buildSpec>
+		<buildCommand>
+			<name>org.eclipse.jdt.core.javabuilder</name>
+			<arguments>
+			</arguments>
+		</buildCommand>
+	</buildSpec>
+	<natures>
+		<nature>org.eclipse.jdt.core.javanature</nature>
+	</natures>
+</projectDescription>

Lesson 2 - Exercise 5 (PC)/.settings/org.eclipse.jdt.core.prefs

+eclipse.preferences.version=1
+org.eclipse.jdt.core.compiler.codegen.inlineJsrBytecode=enabled
+org.eclipse.jdt.core.compiler.codegen.targetPlatform=1.8
+org.eclipse.jdt.core.compiler.codegen.unusedLocal=preserve
+org.eclipse.jdt.core.compiler.compliance=1.8
+org.eclipse.jdt.core.compiler.debug.lineNumber=generate
+org.eclipse.jdt.core.compiler.debug.localVariable=generate
+org.eclipse.jdt.core.compiler.debug.sourceFile=generate
+org.eclipse.jdt.core.compiler.problem.assertIdentifier=error
+org.eclipse.jdt.core.compiler.problem.enumIdentifier=error
+org.eclipse.jdt.core.compiler.source=1.8