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Preston_5564C04.fm Page 133 Wednesday, October 5, 2005 7:22 AM

CHAPTER 4 ■ SENSORS 133

ping_srf:
PULSOUT INIT1,5 ' 10us init pulse
OUTPUT INIT1 ' (delay)
RCTIME ECHO1,1,wDist1 ' measure echo time
wDist1=wDist1/convfac ' convert to inches
SEROUT 16,N9600,[DEC wDist1,CR]
GOTO main

ping_6500:
PULSOUT INIT2,5 ' 10us init pulse
OUTPUT INIT2 ' (delay)
RCTIME ECHO2,1,wDist2 ' measure echo time
wDist2=wDist2/convfac ' convert to inches
SEROUT 16,N9600,[DEC wDist2,CR]
GOTO main

Next is the DistanceStamp class, which reads the data from the distance.bs2 program in
Example 4-7. The fields of this class are similar to the CompassStamp with the exception of the
command names and the instance field distSensor, which enumerates the distance reading.

Example 4-7. DistanceStamp.java

package com.scottpreston.javarobot.chapter5;
import com.scottpreston.javarobot.chapter2.Controller;
import com.scottpreston.javarobot.chapter2.JSerialPort;
import com.scottpreston.javarobot.chapter2.SingleSerialPort;
public class DistanceStamp extends Controller {

// commands set in basic stmap program
public static final int CMD_INIT = 100;
public static final int CMD_IR = 101;
public static final int CMD_SRF = 102;
public static final int CMD_6500 = 103;

private int distSensor = CMD_SRF;

// constructor
public DistanceStamp(JSerialPort sPort) throws Exception {
super(sPort);
}

public int ping(int distSensor) throws Exception {
setDistSensor(distSensor);
return ping();
}