Jazzing Up Your MicroprocessorMicrocontroller Course Through the Infusion of Mobile Robotic Agents U

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Jazzing Up Your Microprocessor/Microcontroller
Course Through the Infusion of Mobile Robotic
Agents Utilizing Basic Stamp II Microcontrollers
for Autonomous Navigation

• Dr. John R. Wright, Jr., CSIT
• Mr. John M. Kuperavage
• Mr. Jason T. Smith
• Department of Industry Technology
• Millersville University of Pennsylvania

http//www.parallax.com/detail.asp?product_id2813
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Emphasis of the Presentation

• (1) How you can infuse the use of a Basic Stamp
  microcontroller into a microprocessor or
  microcontroller course in electronics.
• A) Lab Experiments
• B) Boe-Bots
• C) Custom Ground-up Mobile Robots
• (2) How to construct and integrate this type of
  project into the ITEC curriculum beyond the
  formal curricula.
• A) Independent Studies
• B) Honors Theses
• C) Student Organization Competitions

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Programming Languages

• High-Level Languages
• BASIC, C, C, etc.
• Assembly Language
• Use of mnemonics
• Hex Machine Language
• The programmer writes the program using hex
  codes to represent the op codes, operand
  addresses, and data (Trocci Ambrosio, 2003, p
  171).
• Machine Language
• Remember, the microprocessor does not process
  mnemonics, op codes, or hexadecimal numbers it
  works on binary words (Gilmore, 1996).

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Laboratory Exercises (Before)HeathKit 6800
TrainersHex!

• Programming Experiments
• Binary/Decimal Conversion
• Hex/Decimal Conversion
• Straight Line Programs
• Arithmetic and Logic Instructions
• Program Branching
• Additional Instructions (ADC, SBC, etc.)
• Other Addressing modes (Extended Indexed)

• Interfacing Experiments
• Memory Circuits
• Clock
• Address Decoding
• Data Output
• Data Input
• D/A A/D

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High-Level Language Need Coupled with the Need
for Better I/O Capability

• The Contenders
• Bot Board featuring the Motorola 68HC11/12
• More powerful, faster, more I/O, Industry
  Standard
• Boe-Bot featuring the BASIC STAMP 2
• Popular with Educational Technology/Engineering
  Institutions, very user friendly, curriculum and
  training available, many expandable features

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The Decision!

• When choosing a processor it is important to
  avoid religious wars. Yes, some processors are
  faster than others for a given application, and
  some have very irritating instruction sets.
  Nevertheless the bottom line is, Can it do the
  job and can you get the parts for an appropriate
  cost? Beyond that, there are good and bad
  aspects to every processor family (Morton, 2001,
  p 19).

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Advantages to Parallax, Inc.

• Ease of Use
• PBASIC
• Training
• Documentation (Books Manuals)
• Accessories
• Sensors
• Support
• Sample Code
• Online Groups
• Customization of Packages
• BOE-Bot Kit

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Available Books (Curricula) Great for Lab
Experiments

• Whats a Microcontroller
• Basic Analog Digital
• Digital
• Robotics
• Advanced Robotics
• Applied Sensors
• Industrial Controls
• More

http//www.parallax.com/html_pages/products/books/
books.asp
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Available Downloads (examples)

• Parallax Stamps in Class Educational
  CurriculumDownload the individual texts at the
  related information link.  Includes all curricula
  from What's a Microcontroller through Industrial
  Control.
• Matlab-Based Graphical User Interface Development
  for BASIC Stamp 2 Microcontroller Projects.The
  name Matlab is derived from Matrix Laboratory.
  Matlab is a powerful software package that allows
  for plotting data in multiple dimensions.  This
  article demonstrates it's usage.
• Internet-Based Remote Control using a
  Microcontroller and an Embedded Ethernet
  Board.This article shows a developed DC motor
  position control experimental setup that can be
  accessed via the Internet. The experiment
  consists of two primary elements communicating
  with each other i) a server consisting of a
  low-cost microcontroller, Parallaxs 40-pin Basic
  Stamp 2 module (BS2P40), interfaced with an
  embedded ethernet IC, Cirrus Logics Crystal
  CS8900A, and ii) a client computer.

http//www.parallax.com/html_pages/edu/downloads/d
ownloads.asp
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Some Powerful Stamp 2 Accessories

• Stepper Motor Controller Boards
• Bluetooth Technology
• Field Programmer
• Graphing Software (Stamp Plot)
• Real Time Data Acquisition Software

http//www.parallax.com/html_pages/products/indust
rial/industrial.asp
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What About Industry Grade?

• Parallax offers
• Basic Stamp 2 Industrial Module - Our industrial
  version of the BASIC Stamp 2 module has an
  extended temperature range of -40 C to 85 C (-40
  F to 185 F). This module normally has no
  shortage of program space or I/O pins. Serial PC
  interface provides enhanced debug features.
• Industrial boards -
• 16 or 32 I/O
• Optically Isolated (Opto22)

http//www.parallax.com/html_pages/products/indust
rial/industrial.asp
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Laboratory Exercises (After)HeathKit 6800
Trainers

• Hex!
• Binary/Decimal Conversion
• Hex/Decimal Conversion
• Straight Line Programs
• Arithmetic and Logic Instructions
• Program Branching
• Calculator Challenge

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Laboratory Exercises (After)PBASIC! Boe-Bot
(BS2)

• Whats a Microcontroller
• - Basics
• - Set-up
• Detecting the Outside World
• Inputs
• Variables (bit, nib, byte, word)
• Micro-controlled Movement
• Servo Motor Control
• For/Next Loops
• Time Delays
• Simple Automation
• Debug (Print)
• Tying it all together
• Measuring an Input
• Interfacing to Integrated Circuits (555)
• Assembling Testing Your Boe-Bot
• Basics
• Set-up
• Tuning the servos (calibration)

• Programming the Boe-Bot to go Places
• Low battery indicator
• Distance control
• Turning/Maneuvers
• Ramping Speeds
• EEPROM Navigation
• Branching/Subroutines
• Tactile Navigation
• Navigation with whiskers
• If/Then Statements
• Logic (XOR, Not, etc.)
• Light Sensitive Navigation with Photoresistors
• Measuring RC time
• Deadband
• Object Detection Using Infrared
• Frequency manipulation (Freqout)
• Real-time Navigation

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Suggested Course Lectures

• What is a Microprocessor?
• Basic Microprocessor Architectural Concepts
  (part I)
• Basic Microprocessor Architectural Concepts
  (part II)
• Inside the Microprocessor
• An Introduction to Microprocessor Instructions
• Communicating with the Microprocessor
• Memory
• Mass Storage
• Introduction to Microcontrollers
• The Basics of PBASIC
• Advanced PBASIC Instructions

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Why Dont We Just Eliminate Teaching Assembly?

• An assembly language program makes very compact
  code, but it takes a great deal of programming
  time. High-level languages take much less
  development time but take much more memory space
  than assembly programs (Gilmore, 1996).
• However, semiconductor memory costs continue to
  drop.
• Its a question of whats more expensive
• Extra Memory
• Extra Engineering Development Time
• Product quantity plays a huge role!

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Beyond the Traditional Classroom

• Honors Thesis Topic
• Independent Study
• MU Robotics Team

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Honors Thesis Topic

• Honors Thesis Creating an equation to determine
  of the optimum number of IR sensors needed for
  object detection.
• The basis for this study was to prove that the
  optimal number of IR sensors (timed efficiency
  vs. cost) is directly related to an objects size
  in a given array.

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Major Components Used

• BASIC Stamp 2 with carrier board
• This allows for powerful capabilities of
  interfacing sensors to control your output but
  the PBASIC is simple enough to program with
  limited programming background.
• Parallax S.S.I.R Sensors
• Infrared detection unit which is made to be used
  with the stamp directly with no other
  interfacing.
• BOE Bot
• Board of Education Bot carries the stamp carrier
  board and allows for movement with virtually no
  fabrication.

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Reason For Using These Components

• Object of the study was to determine sensor
  optimization in general. The Stamp is a simple
  way to draw conclusions that can be later
  transferred to more advanced systems.
• The Parallax S.S.I.R is designed specifically for
  use with the stamp therefore all the circuitry
  for operation is already included on the chip.
• Although the BOE bot is simple, it is also
  extremely reliable. All components can be bought
  in a kit and assembled quickly. The only
  fabrication needed is for the sensor mounting.

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Using IR

• The S.S.I.R. is an infrared detection unit
• Uses an LED to emit infrared light, which when
  bounced off an object can be detected.
• Both the emitter and the detector use the same
  port which gives added efficiency.
• Tuning the S.S.I.R. is possible by changing the
  frequency of the LED.
• Frequency changes your range of detection.

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On/Off control in two zones

• The array field is divided up into two zones
  each with on/off control logic.

• Nine sensors will be placed in an array in front
  of the BOE bot.
• When an object is detected by a sensor, the Stamp
  sets a variable as high to designate detection on
  that side.
• The stamp then turns the opposite direction of
  which ever zone the object was detected in.
• The BOE bot turns until the center IR detects the
  object. The BOE Bot then drives forward until it
  reaches the object.

Left Zone
Right Zone
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Algorithm
Initial Search
Centering the BOE bot on the Object
Driving to the Object
Does the center IR detect the can?
BOE bot Drives forward for .2 seconds
No
Yes
Yes
BOE bot Drives forward for .2 seconds
Does the center IR detect the can?
No
BOE Bot checks status of Limit Switch
BOE Bot checks status of sensors
BOE Bot checks status of sensors
BOE Bot checks status of sensors
BOE bot turns left for .2 seconds
Is the limit switch touched?
No
No
Is there detection in the right zone?
Is there detection in the left zone?
Yes
BOE bot turns right for .2 seconds
No
Yes
Object Found
Yes
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Experiment Setup

• To test our hypothesis we will need to set up an
  experiment
• An object will be placed within the arrays arc
  but out of its range.
• A number of sensors will be turned on starting
  with three in the first trial and ending with
  nine in the last trial.
• The three sensors include a middle sensor, one at
  the left limit, and one at the right limit.
• Each trial will increase the number of sensors
  turned on by two (one for each side) spaced
  equally apart.
• The sensors will be turned on and off within the
  code.
• The operation will then be started and timed.

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Experiment Setup Continued

• We will perform all four trials 10 times each and
  come up with an average time for each trial.
• This will be done with several objects of
  different sizes (TBD).
• Graphs will be formulated using the average
  times, number of sensors and object size.
• These graphs will be used to draw conclusions
  about the relationship between object size and
  number of sensors, based on time.

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Assumptions/Limitations

• Assumptions
• Objects will always be places in the same
  position in relation to the BOE Bot.
• Power supply is constant
• Timing will be from start of motion to the end of
  motion.
• Code will not be altered (Except for turning
  sensors on and off).

• Limitations
• Experiment is to be done on a flat smooth indoor
  surface.
• Object will be a solid color.
• Sensor range is limited to approximately two
  feet.
• All servo and wheel components will be standard
  Parallax components that have come with the BOE
  bot kit.

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In Progress

• This study is currently in progress.
• The exact code has not been finalized nor have
  any of the trials been run.
• I expect the trials to be run and my conclusions
  to be drawn in the Spring of 2005 at which time I
  will defend my findings in front of my thesis
  committee at Millersville University.

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Beyond the Traditional Classroom

• Honors Theses Topic
• Independent Study
• MU Robotics Team

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Independent Study

• The purpose of this study was to establish a
  semi-autonomous mode in order to control a
  robotic device and then complete an assigned
  task.
• The integration of the two modes allow for both
  tele-operated functions from the user and
  automated control when the Basic Stamp II was in
  operation.

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Semi-Autonomous Control Scheme Overview
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The New Communication Standard

• Bluetooth is a wireless communication technology
  that was chiefly employed for data transfer and
  control during the study.
• Bluetooth class one technology has a range of
  100m or about 330ft.
• The use of Bluetooth technology as a low cost,
  low power, high data rate transfer mechanism
  helped to make the real time control and
  semi-autonomous modes a reality.

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The Control Link

• Bluetooth technology allowed for the seamless
  integration of control.
• Information was sent through the EmbeddedBlue
  500. which is available through parallax Inc.
• The Bluetooth technology allows for communication
  through any other class I Bluetooth device.

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Virtual Serial Port

• The program is first downloaded into the stamp
  via hardwire connection.
• All of the Bluetooth code must be preprogrammed
  in to facilitate communication between computer
  and Basic Stamp II.
• Once the code is downloaded into the Basic Stamp
  II the user opens up HyperTerminal.
• HyperTerminal communication must be configured
  and then the virtual serial port link can be
  established.

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Real Time Monitoring One Key Control

• Real Time Monitoring
• With the serial communication establish
  information can be sent and received through the
  uplink.
• This allows for Real Time Monitoring of any
  sensors interfaced with the basic Stamp II.
• One Key Control
• The User can then initiate the Basic Stamp IIs
  preprogrammed functions by a single key stroke.
• In the study for example subroutines were used to
  check for user input and then execute a set of
  instructions.
• User-override feature utilized.

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Superior Signal Strength

• Interfacing the Basic Stamp II, motor speed
  controller and tele-operated receiver was
  interesting.
• Wiring the entire system in parallel turned out
  to be the answer because of the Basic Stamp IIs
  superior signal strength it was able to
  lock-out functions from the tele-operated
  receiver.
• The Basic Stamp II only locks-out outputs which
  the program sends digital signals to this means
  that a truly semi-autonomous state can be
  achieved thus Real time monitoring was developed.

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Beyond the Traditional Classroom

• Honors Theses Topic
• Independent Study
• MU Robotics Team

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Latest Design (SA-1)
Semi-Autonomous One 2004 MU Robotics Team
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Texts Cited

• Gilmore, C. M. (1996). Microprocessors Principles
  and Applications 2nd Edition. Glencoe
  McGraw-Hill, New York.
• Morton, T. D. (2001). Embedded Microcontrollers.
  Prentice Hall, Upper Saddle River, New Jersey.
• Tocci R. J. (2003). Microprocessors and
  Microcomputers Hardware and Software 6th Edition.
  Prentice Hall, Columbus, Ohio.

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Thank You!
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Parallax Stamps (Appendix A)

• BS2 (Low-end Model)
• Processor Speed 20 MHz
• Program Execution Speed 4,000 instructions/sec.
• RAM Size 32 Bytes (6 I/O, 26 Variable)
• EEPROM (Program) Size 2K Bytes, 500
  instructions
• Number of I/O pins 16 2 Dedicated Serial
• Cost 49 each
• BS2p40 (High-end Model)
• Processor Speed 20 MHz Turbo
• Program Execution Speed 12,000
  instructions/sec.
• RAM Size 38 Bytes (12 I/O, 26 Variable)
• EEPROM (Program) Size 8x2K Bytes, 4,000
  instructions
• Number of I/O pins 32 2 Dedicated Serial
• Cost 89 each

http//www.parallaxinc.com/html_pages/tech/faqs/st
amp_specs.asp
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Motorolas Microcontrollers (Appendix B)

• 68HC11
• 512 bytes of RAM
• 2K bytes EEPROM
• 40 I/O pins
• 2 MHz
• 45-100 Million Instructions per Second
• Used with the BOT Board
• 68HC12
• 1024 bytes of RAM
• 4K bytes EEPROM
• 96 I/O pins
• 8 MHz

Note Both can be programmed with SBASIC
developed by Karl Lunt
http//www.seattlerobotics.org/encoder/jan97/The68
HC12.html http//www.dcd.pl/dcdpdf/alt/df6811cpu_d
s.pdf