Robotics with the Boe-Bot text v2.2
Page 232 ยท Robotics with the Boe-Bot 
' -----[ Title ]---------------------------------------------------------- 
' Robotics with the Boe-Bot - TestBlackWhiteLogic.bs2 
' Calculate whether Boe-Bot is over black or white surface, and print. 
' {$STAMP BS2} ' Stamp directive 
' {$PBASIC 2.5} ' PBASIC directive. 
' -----[ Constants ]------------------------------------------------------ 
LeftWhite CON 16 
RightWhite CON 33 
LeftBlack CON 26 
RightBlack CON 45 
LeftAvg CON LeftWhite + LeftBlack / 2 
RightAvg CON RightWhite + RightBlack / 2 
' -----[ Variables ]------------------------------------------------------ 
timeLeft VAR Word ' Left photoresistor reading 
timeRight VAR Word ' Right photoresistor reading 
' -----[ Main Routine ]--------------------------------------------------- 
DO 
 GOSUB Test_Photoresistors 
 IF (timeLeft > LeftAvg) THEN 
 DEBUG CRSRXY, 0, 0, "Left Black " 
 ELSE 
 DEBUG CRSRXY, 0, 0, "Left White " 
 ENDIF 
 IF (timeRight > RightAvg) THEN 
 DEBUG CRSRXY, 13, 0, "Right Black", CR 
 ELSE 
 DEBUG CRSRXY, 13, 0, "Right White", CR 
 ENDIF 
LOOP 
' -----[ Subroutine - Test_Photoresistors ]------------------------------- 
Test_Photoresistors: 
 HIGH 6 ' Left RC time Measurement. 
 PAUSE 3 
 RCTIME 6,1,timeLeft 
 HIGH 3 ' Right RC time measurement. 
 PAUSE 3 
 RCTIME 3,1,timeRight 
RETURN 
To develop a program that makes the Boe-Bot avoid the black sheets of paper, 
the decision and navigation steps required are very similar to 










