The George Washington University Department of ECE ECE 001 - Intro: Electrical

1
The George Washington University Department of
ECE ECE 001 - Intro Electrical Computer
Engineering

• Intro to the Robotics
• Introducing the IC
• Discuss motor control using IC
• Hands-on programming
• Dr. S. Ahmadi
• Class 1
• Slides obtained from Botball Kit Documentation

2
Class Outline

• Policy and Safety
• Basic IC programming
• Download
• Display
• Function commands
• Botball Part list
• http//www.seas.gwu.edu/ece001/partlist.doc
• Overview of Motors

3
How to Write a SIMPLE Interactive C (IC) Computer
Program

• IC is a hybrid of C designed to run on small,
  self-contained robot controllers
• void main()
• Making decisions
• If ( ) statement
• Else( ) statement
• Making repeated decisions
• While( ) statement

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How to Write a SIMPLE Interactive C (IC) Computer
Program

• IC is a hybrid of C designed to run on small,
  self-contained robot controllers
• void main()
• // This is a comment
• int my_variable // my_variable is of type
  integer
• my_variable 2 // assinging a variable
• motor(1, my_variable) // a function call, turns
  on motor
• float my_second_variable // my_second_variable
  is of type float
• my_second_variable 2(3/6)5 // mathematical
  expression using C
• my_second_variable sqrt((a2)(b2))
• Important All statements end with a semicolon
  ().
• Making decisions
• If ( ) statement
• Else( ) statement
• Making repeated decisions

5
Variable Types

• What is a variable?
• It holds information, for example a number
• Two types of variables we will use in ECE001
• int (16 bit integer number in IC)
• /-32,767 (largest it can hold)
• float (32 bit floating point number)
• e.g. 3.1416

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Useful Function

• Sleep(seconds)
• sleep() delays the functions execution for an
  amount of time equal to the number of seconds
  (expressed as a float) given as an argument

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C Function printf()

• Takes a quoted string and prints it out
• d is used for an integer
• f is used for a float
• \n starts next character back at upper left
  corner (or new line on terminal)
• commas separate all arguments after the quoted
  string
• printf(Im printing\n)

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Handyboard Functions

• start_button()
• stop_button()
• beep()
• fd(x) // makes motor x go forward
• bk(x) // makes motor x go backward
• ao() // turns all motors off --- all off

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Sample Program

• When a program is run, the control moves from one
  statement to the next
• Calculate j2 1 when j 3
• void main()
• int r,j / declare r and j /
• j 3 / assign a value to j /
• r jj 1 / calculate and assign /
• printf(result is d\n,r)

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Making decision Using if-else condition

• void main()
• if ( start_button()1)
• fd(1) fd(2)
• else
• ao()

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Repeating Execution Loops

• Loops are used when you want to do the same thing
  multiple times
• E.g., beep 20 times
• You could type beep() 20 times, but there is a
  better way a loop

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Repetition Using while

• Syntax while (lttestgt) statements
• Beep 20 times
• void main()
• int num / declare counter /
• num 1 / initialize counter /
• while (num lt 20) / loop while num is lt20/
• beep() / beep once /
• num num 1 / add one to the counter /

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Get Started with IC Environment

• Start the IC application
• Click on the picture of the Handy Board
• Click on the Connect Later button
• Click on the New button (upper left corner)
• Type in the program that prints out a text string
• Save the file using the Save button (name it
• whatever you want -- just remember where you put
  it).

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Important Information

• How to learn IC programming
• http//www.kipr.org/curriculum/programming.html
• Check class website for Handy board documentation
• Check IC command functions
• Check the handy board diagram
• Return the Kit release form after you check all
  parts in the Kit
• Homework is to be done individually