1. The George Washington University Department of ECE ECE 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
• 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
int main() {
return 0; }
Making decisions
If ( ) { statement }
Else( ) { statement }
Making repeated decisions
While( ) { statement }

4. 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
int 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((a^2)+(b^2));
return 0; // exit code meaning the program has terminated // successfully }
Important: All statements end with a semicolon (;).
Making decisions
If ( ) { statement }
Else( ) { statement }
Making repeated decisions
While( ) { statement }

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

6. Sleep(seconds); Useful Function:
sleep() delays the function’s execution for an amount of time equal to the number of seconds (expressed as a float) given as an argument

7. printf(“I’m printing\n”);
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(“I’m printing\n”);

8. Handyboard Functions a_button(); b_button(); c_button(); beep();
fd(x); // makes motor “x” go forward
bk(x); // makes motor “x” go backward
ao(); // turns all motors off --- “all off”

9. Sample Program
When a program is run, the control moves from one statement to the next
Calculate j2 + 1 when j = 3
int main() {
int r,j; /* declare r and j */
j = 3; /* assign a value to j */
r = j*j + 1; /* calculate and assign */
printf(“result is %d\n”,r);
return 0; }

10. Making decision Using if-else condition
int main() {
if ( start_button()==1)
{ fd(1); fd(2); }
else
{ ao(); }
return 0; }

11. 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

12. Repetition Using while
Syntax: while (<test>) {statements}
Beep 20 times
int main() {
int num; /* declare counter */
num = 1; /* initialize counter */
while (num <= 20) /* loop while num is <=20*/
beep(); /* beep once */
num = num + 1; /* add one to the counter */ }
return 0;

13. 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).

14. Important Information
How to learn IC programming
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