Activity #6: The Drop-Off Detector - Parallax Boe-Bot Student Manual

ACTIVITY #6: THE DROP-OFF DETECTOR

Up until now, the Boe-Bot has mainly been programmed to take evasive maneuvers when
an object is detected. There are also applications where the Boe-Bot must take evasive
action when an object is not detected. For example, if the Boe-Bot is roaming on a table,
its IR detectors might be looking down at the table surface as shown in Figure 7-8. The
program should make it continue forward so long as both IR detectors can "see" the
surface of the table. In other words, the Boe-Bot can continue forward so long as the
table top it's navigating on is detected.
√
Disconnect power from your board and servos.
√
Point your IR pairs downward and outward as shown in Figure 7-8.
To Servos
15 14 Vdd 13 12
Red
Black
X4 X5
Vdd Vin Vss
X3
P15
P14
P13
P12
P11
P10
P9
P8
P7
P6
P5
P4
P3
+
P2
P1
P0
X2
Board of Education
Rev C
© 2000-2003
Top View
Recommended Materials:
(1) Roll of black vinyl electrical tape – ¾" (19 mm) wide.
(1) Sheet of white poster board – 22 x 28 in (56 x 71 cm).
Simulating a Drop-Off with Electrical Tape
A sheet of white poster board with a border made of electrical tape makes for a handy
way to simulate the drop-off presented by a table edge, with much less risk to your Boe-
Bot.
Chapter 7: Navigating with Infrared Headlights · Page 255
Side View
Figure 7-8
IR Pairs
Directed
Downwards to
Scan for a
Drop-Off