Page 108 - The Definitive Guide to Building Java Robots

Preston_5564C03.fm Page 89 Wednesday, October 5, 2005 7:21 AM

CHAPTER 3 ■ MOTION 89

// helper method to get difference
private int getTotalDiff() {
int totalDiff = 0;
for (int i = 0; i < commands.size(); i++) {
ServoPosition newPos = (ServoPosition) commands.get(i);
ServoPosition curPos = (ServoPosition) servos.get(newPos.pin);
int tmpDiff = Math.abs(newPos.pos - curPos.pos);
totalDiff = totalDiff + tmpDiff;
}
return totalDiff;
}

private ServoPosition getServo(int id) {
return (ServoPosition) servos.get(id);
}

// sample program same as LM32
public static void main(String[] args) {
try {
// get single serial port instance
JSerialPort sPort = (JSerialPort) SingleSerialPort.getInstance(1);
// create new LM32
MiniSscGM miniSscGM = new MiniSscGM(sPort);
// sets position for servo at pin 0
miniSscGM.sscCmd(0, 100);
// sets position for servo at pin 1
miniSscGM.sscCmd(1, 200);
// tells the servos to move there in 1 second.
miniSscGM.move(1000);
// close serial port
sPort.close();
} catch (Exception e) {
// print stack trace and exit
e.printStackTrace();
System.exit(1);
}

}
}

Section Summary
You can see from the GroupMoveProtocol that the LM32 has a lot of advantages over the
SSCProtocol when you want smoother movement or have a lot of servos you want to command
at once.