1. Chapter 5: Tactile Navigation With Whiskers
Presentation based on: "Robotics with the Boe-Bot"
By Andy Lindsay Parallax, Inc
Presentation developed by: Martin A. Hebel Southern Illinois University Carbondale
College of Applied Sciences and Arts
Electronic Systems Technologies
7/6/04

2. Tactile Whiskers as switches

6. Whisker "switch" open and closed

7. Code to View Whisker Switch States
DO:
DEBUG CLS, ? IN5, ? IN7
Pause 100
LOOP
See "TestWhisker.bs2"

8. Adding LED Indication

9. Code using IF…THEN

10. AI – Escaping Corners
' --- Detect Consecutive Alternate Corners
' See the "How EscapingCorners.bs2 Works" section that follows this program.
IF (IN7 <> IN5) THEN ' One or other is pressed.
IF (Old7 <> IN7) AND (Old5 <> IN5) THEN ' Different from previous.
counter = counter ' Alternate whisker count + 1.
old7 = IN ' Record this whisker press
old5 = IN ' for next comparison.
IF (counter > 4) THEN ' If alternate whisker count = 4,
counter = ' reset whisker counter
GOSUB Back_Up ' and execute a U-turn.
GOSUB Turn_Left
ENDIF ' ENDIF counter > 4.
ELSE ' ELSE (old7=IN7) or (old5=IN5),
counter = ' not alternate, reset counter.
ENDIF ' ENDIF (old7<>IN7) and
' (old5<>IN5).
ENDIF ' ENDIF (IN7<>IN5).

11. Moving Forward

12. Simplifying Navigation with Subroutines
GOSUB – Used to temporarily branch to another a section of code.
Return – Used to return to where it jumped from.
See program "OneSubroutine.bs2"

13. Roaming with Whiskers
See "RoamingWithWhiskers.bs2"