1. Parallax, Inc. Presentation based on: “Robotics: with the Boe-Bot"
599 Menlo Drive
Suite 100
Rocklin, CA

2. Copyrights and Trademarks
This documentation is copyright 2004 by Parallax, Inc. By downloading or obtaining a printed copy of this documentation or software you agree that it is to be used exclusively with Parallax products. Any other uses are not permitted and may represent a violation of Parallax copyrights, legally punishable according to Federal copyright or intellectual property laws. Any duplication of this documentation for commercial uses is expressly prohibited by Parallax, Inc. Duplication for educational use is permitted subject to the following conditions: Parallax grants the user a conditional right to download, duplicate, and distribute this text without Parallax's permission. This right is based on the following conditions: the document, or any portion thereof, may not be duplicated for commercial use; it may be duplicated only for educational purposes when used solely in conjunction with Parallax products, and the user may recover from the student only the cost of duplication.
BASIC Stamp, Stamps in Class, and Board of Education are registered trademarks of Parallax, Inc. If you decide to use the names BASIC Stamp, Stamps in Class, and/or Board of Education on your web page or in printed material, you must state that "BASIC Stamp is a registered trademark of Parallax, Inc.," "Stamps in Class is a registered trademark of Parallax, Inc.," and/or "Board of Education is a registered trademark of Parallax, Inc.," respectively, upon the first appearance of the trademark name. Other brand and product names are trademarks or registered trademarks of their respective holders.

3. What's New In Robotics New Servos Adjustable potentiometer
Faster, quieter, draw less power
New Board of Education
Power Switch
Jumper
New Wheels and Tires
New Whiskers
New Infrared Emitters
New Text – v2.0
PBASIC 2.5
Not used in Robotics! v.1.5 text

4. Select the Servo Power Supply
New jumper - connects servo power to either
Vin – Battery Voltage
Vdd – Regulated 5V supply
Select Vin for use with 4 AA batteries
Pull jumper off pins, then push onto Vin pin

5. Center the Boe-Bot Servos
Plug the battery pack into the BOE
Note the correct polarity
Plug the servos in to the BOE
Important!! Black wire closest to breadboard!
Turn the switch to Position 1
Enter and Run "CenterServoP12.bs2" pg. 65
Repeat for "CenterServoP13.bs2" pg. 66

6. Center the Boe-Bot Servos
Move the switch to Position 2
If the servos do not stay still, adjust them with your Parallax screwdriver
Do not push too hard
Use the Phillips end
Adjust each servo so it stays completely still

7. Build the Boe-Bot
Build the robot by following instructions from your manual (pages 85-99)
Explain they’ll find some little differences on the manual because they have improved hardware.

8. Build the Start/Reset Indicator
Brownout
Batteries drop below 5.2 V
Brownout detector circuit resets the BASIC Stamp
Program starts over from beginning
Low Battery Indicator
Add speaker to Boe-Bot
"Beep" first thing in program
If Boe-Bot beeps during navigation, must have reset
Thus batteries are low
Figure 3-18 p 102

9. Test the Low Battery Indicator
Run "StartResetIndicator.bs2"
Test by pressing the Reset button on the BOE
Should beep each time reset
DEBUG CLS, "Beep!!!" ' Display while speaker beeps.
FREQOUT 4, 2000, ' Signal program start/reset.
DO ' DO...LOOP
DEBUG CR, "Waiting for reset…" ' Display message
PAUSE ' every 0.5 seconds
LOOP

10. Servo Positioning Pulse Width Direction of Rotation PULSOUT Period
Determined by the width of the pulse
Distance
Each pulse causes the servo to rotate a small amount
Speed
Maximum at 1.3 and 1.7 ms.
Decreases as approaches 1.5 ms
Pulse Width
Direction of Rotation
PULSOUT Period
1.3 ms
Clockwise
650
1.5 ms
Stopped
750
1.7 ms
Counter-clockwise
850
km – p. 73 new text

11. Controlling Distance Run "BoeBotForwardThreeSeconds.bs2"
Follow the instructions on p. 118 to make the Boe-Bot go half as far forward
Add code to make the Boe-Bot go backward, left, and right, as shown on pages
FOR counter = 1 TO 122
PULSOUT 13, 850
PULSOUT 12, 650
PAUSE 20
NEXT
put new code here

12. EEPROM Navigation Run "EEPROMNavigation.bs2" p. 141
Modify the DATA directive to make your own motion sequence
DATA "FFFBBLFFRFFQ"
F = Forward, B = Backward, L = Left, R = Right, Q = Quit DO
READ address, instruction
address = address + 1
SELECT instruction
CASE "F": GOSUB Forward
CASE "B": GOSUB Backward
CASE "L": GOSUB Left_Turn
CASE "R": GOSUB Right_Turn
ENDSELECT
LOOP UNTIL instruction = "Q"
address VAR Byte
instruction VAR Byte
' Address:
' ||||||||||
DATA "FLFFRBLBBQ"
km – modify code listing

13. Tactile Navigation with Whiskers
Activities:
Building and Testing the Whiskers
Page
See also wiring diagram next slide
km – Remove this slide?

14. Build the Whisker Circuit
km -- Figure 5-4 and 5-5 p
With added LEDs Figure p

15. Testing the Whiskers Run "TestWhiskers.bs2" p.160
Press on each whisker and examine the Debug Terminal output.
Each whisker should display 1 when not pressed, 0 when pressed.
Position the whisker wires to make good contact with the headers
DEBUG "WHISKER STATES", CR,
"Left Right", CR,
" " DO
DEBUG CRSRXY, 0, 3,
"P5 = ", BIN1 IN5,
" P7 = ", BIN1 IN7
PAUSE 50
LOOP
p. 159
replace code listing

16. Navigation With Whiskers
Run "Roaming with Whiskers.bs2"
Compare with pushbuttons exercise from the previous day DO
IF (IN5 = 0) AND (IN7 = 0) THEN ' Both whiskers detect obstacle
GOSUB Back_Up ' Back up & U-turn (left twice)
GOSUB Turn_Left
ELSEIF (IN5 = 0) THEN ' Left whisker contacts
GOSUB Back_Up ' Back up & turn right
GOSUB Turn_Right
ELSEIF (IN7 = 0) THEN ' Right whisker contacts
GOSUB Back_Up ' Back up & turn left
ELSE ' Both whiskers 1, no contacts
GOSUB Forward_Pulse ' Apply a forward pulse
ENDIF ' and check again
LOOP

17. Navigation with Infrared Headlights
Activities:
Understanding Infrared Object Detection
Building and Testing the IR Circuit
Object Detection and Avoidance
Object Detection and Avoidance in Real-Time

18. Using Infrared Headlights to See the Road
IR reflect off obstacles
IR LED emits light in infrared region (780 nm)
Detector shows "0" if detects IR, "1" otherwise
Detector tuned to 38,500 Hz only
km – new diagram Figure 7-1 p. 218

19. Building and testing the IR Pairs
Figure p
Run "TestLeftIrPair.bs2"
Follow directions on p. 223 to test right IR pair

20. How the IR Test Program Works
' Robotics with the Boe-Bot - TestLeftIrPair.bs2
' Test IR object detection circuits, IR LED connected to P8
' and detector connected to P9.
' {$STAMP BS2}
' {$PBASIC 2.5}
irDetectLeft VAR Bit DO
FREQOUT 8, 1, 38500
irDetectLeft = IN9
DEBUG HOME, "irDetectLeft = ", BIN1 irDetectLeft
PAUSE 100
LOOP
TestLeftIRPair.bs2 p. 222

21. Object Detection and Avoidance
Run "RoamingWithIr.bs2"
IF (irDetectLeft = 0) AND (irDetectRight = 0) THEN
GOSUB Back_Up
GOSUB Turn_Left
ELSEIF (irDetectLeft = 0) THEN
GOSUB Turn_Right
ELSEIF (irDetectRight = 0) THEN
ELSE
GOSUB Forward_Pulse
ENDIF
RoamingWithIr.bs2
Place the Boe-Bot on the floor
Your Boe-Bot should roam around and avoid objects

22. Again the Boe-Bot should roam around and avoid objects
Fast IR Roaming
Run "FastIRRoaming.bs2"
Again the Boe-Bot should roam around and avoid objects
Observe: How does this behavior differ from that of "RoamingWithIr.bs2"?
IF (irDetectLeft = 0) AND (irDetectRight = 0) THEN
pulseLeft = 650
pulseRight = 850
ELSEIF (irDetectLeft = 0) THEN
pulseLeft = 850
ELSEIF (irDetectRight = 0) THEN
pulseRight = 650
ELSE
ENDIF
"FastIRRoaming.bs2"

23. Understanding Filter Sensitivity
Figure 8-1 p. 248
Figure 8-2 p. 249
TestLeftFrequencySweep.bs2
Screen Shot? Figure 8-3 p. 251

24. Testing Distance Detection
Run "TestLeftFrequencySweep.bs2"
Place the Boe-Bot in front of some obstacle (Wall, book, etc)
Observe the readings change as you move the Boe-Bot closer to and further away from the obstacle

25. Boe-Bot Shadow Vehicle
Follow the detailed instructions on p
In summary:
Run "FollowingBoeBot.bs2"
Place a sheet of paper in front of your Boe-Bot
Move the paper around
The Boe-Bot should follow the paper at a constant distance
If the Boe-Bot backs away instead, contact the instructor for assistance. Your right/left servos are probably reversed.

26. Boe-Bot Follow-the-Leader
Place sticky notes on the back of all Boe-Bots
Now select two or three Boe-Bots from the class to be "Leader" Boe-Bots
Create "Leader" Boe-Bots by following the instructions on p. 263
All other Boe-Bots keep the previous program, "FollowingBoeBot.bs2"
The "Shadow" Boe-Bots will follow the "Leader" Boe-Bots
See how many Boe-Bots will follow in a row, like a train
FollowingBoeBot.bs2

27. Create Stripe-Following Boe-Bots
Following a Stripe
Create Stripe-Following Boe-Bots
Follow the instructions on pp
Make sure to point IR pairs downward as detailed in text
Figure 8-7 p. 264 – The Course
Figure 8-8 p. 265 – The IR Pairs going downward ?

28. Focus on Proportional Control
The Boe-Bot will follow a moving object by maintaining a constant distance from it. The amount of correction is directly proportional to the error. That is, the Boe-Bot will speed up or slow down a varying amount, depending on how far away the object is.
Distance
Reading
Meaning
Left Wheel
PULSOUT
Wheel
Direction
Robot motion
Far Away
650
Clockwise
Backward fast 2
Desired distance
680
Backward slow 5
Very close
750
Stopped
820
Counter-clockwise
Forward slow
850
Forward fast
New servo params

29. Proportional Control Block Diagram
Desired
Distance
Measured
Boe-Bot is…
What to
do…
Error
Output
Adjustment
Left Servo
Robot Motion 2 4
A bit too close
Go backward
2–4 = -2
-35 * -2 =
-70
750 + (-70) = 680
Backwards slow 5
Much too close
2-5 = -3
-35 * -3 =
-105
750 + (-105) = 645
Backwards fast 1
Much too far away
Go forward ?
A bit too far away
Figure 8-5 p. 258 – Left
Figure 8-4 p Right

30. The End We hope you enjoyed this Educator's Course
Don't hesitate to contact us for any reason!