Page 145 - The Definitive Guide to Building Java Robots

Preston_5564C04.fm Page 126 Wednesday, October 5, 2005 7:22 AM

126 CHAPTER 4 ■ SENSORS

main:
SERIN 16,16468,main,[WAIT(100), cmd]
IF cmd = 101 THEN single_switch
IF cmd = 102 THEN multi_switch
PAUSE 5
GOTO main

single_switch:
IF switch1 = 0 THEN
SEROUT 16,N9600,["0", CR]
GOTO main
ENDIF
IF switch1 = 1 THEN
SEROUT 16,N9600,["1", CR]
GOTO main
ENDIF
multi_switch:
IF m_switch1 = 0 THEN
SEROUT 16,N9600,["0", CR]
ENDIF
IF m_switch1 = 1 THEN
SEROUT 16,N9600,["1", CR]
ENDIF
IF m_switch2 = 0 THEN
SEROUT 16,N9600,["0", CR]
ENDIF
IF m_switch2 = 1 THEN
SEROUT 16,N9600,["1", CR]
ENDIF
IF m_switch3 = 0 THEN
SEROUT 16,N9600,["0", CR]
ENDIF
IF m_switch3 = 1 THEN
SEROUT 16,N9600,["1", CR]
ENDIF
GOTO main
The corresponding Java class for this BASIC Stamp program is SwitchStamp. The class has
static fields for enumeration of the commands and the switches connected to the stamp pins.
The getSingle() method looks for a single character “1” or “0” to be returned from the
program. As for the two methods getMulti(): one takes an index parameter that returns a specific
reading, and the other returns the entire string of ones or zeroes.
In the main method(), I show the examples of usage of each of these methods (see
Example 4-5).