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

Class Outline Policy and Safety Basic IC programming Download Display Function commands Botball Part list https://blogs.gwu.edu/ece1010/course-material • Overview of Motors

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 }

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 }

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

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

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”);

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”

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; }

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

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

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;

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).

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