Page 77 - The Definitive Guide to Building Java Robots

Preston_5564C03.fm Page 58 Wednesday, October 5, 2005 7:21 AM

58 CHAPTER 3 ■ MOTION

// accessor
public int getMaxPin() {
return maxPin;
}
// setter
public void setMaxPin(int maxPin) {
this.maxPin = maxPin;
}

}
Now that the general super-class has been created, it’s time to create a specific class for the
MiniSSC-II. This class has no fields and simply calls the parent constructor and setMaxPin
method to limit the total pins to seven.
In the example program in main(), I call the same logic that composed the class SerialSSC
in Example 3-2. Move the servo through the range of motion in 5-byte increments. You’ll note
that its command structure is simpler (no bytes to create or cast), and you have error control
built in. (See Example 3-5.)

Example 3-5. MiniSsc.java
package com.scottpreston.javarobot.chapter3;

import com.scottpreston.javarobot.chapter2.JSerialPort;
import com.scottpreston.javarobot.chapter2.SingleSerialPort;
import com.scottpreston.javarobot.chapter2.Utils;

public class MiniSsc extends Ssc implements SSCProtocol {

// calls super and sets max pin to 7
public MiniSsc(JSerialPort serialPort) throws Exception {
super(serialPort);
setMaxPin(7);
}

// sample program
public static void main(String[] args) {
try {
// get single serial port instance
JSerialPort sPort = (JSerialPort) SingleSerialPort.getInstance(1);
// create new miniSSc
MiniSsc ssc = new MiniSsc(sPort);