Book Image

Programming the BeagleBone

By : Yogesh Chavan, Amit Pandurang Karpe
Book Image

Programming the BeagleBone

By: Yogesh Chavan, Amit Pandurang Karpe

Overview of this book

The whole world is moving from desktop computers to smartphones and embedded systems. We are moving towards utilizing Internet of Things (IoT). An exponential rise in the demand for embedded systems and programming in the last few years is driving programmers to use embedded development boards such as Beaglebone. BeagleBone is an ultra-small, cost-effective computer that comes with a powerful hardware. It runs a full-fledged Debian Linux OS and provides numerous electronics solutions. BeagleBone is open source and comes with an Ethernet port, which allows you to deploy IoT projects without any additions to the board. It provides plenty of GPIO, Anlaog pins, and UART, I2C, SPI pins which makes it the right choice to perform electronics projects. This gives you all the benefits of Linux kernel such as multitasking, multiusers, and extensive device driver support. This allows you to do programming in many languages including high-level languages such as JavaScript and Python. This book aims to exploit the hardware and software capabilities of BeagleBone to create real-life electronics and IoT applications quickly. It is divided into two parts. The first part covers JavaScript programs. The second part provides electronics projects and IoT applications in Python. First, you will learn to use BeagleBone as tool to write useful applications on embedded systems. Starting with the basics needed to set up BeagleBone and the Cloud9 IDE, this book covers interfacing with various electronics components via simple programs. The electronics theory related to these components is then explained in depth before you use them in a program. Finally, the book helps you create some real-life IoT applications.
Table of Contents (21 chapters)
Programming the BeagleBone
Credits
About the Author
Acknowledgment
About the Reviewers
www.PacktPub.com
Preface
BeagleBone Capes
Index

Dancing LEDs


BeagleBone has four onboard LEDs adjacent to each other. Let's create an LED on/off pattern so that we get an illusion of dancing LEDs. We will follow the turning on the LED sequence: USER0 -> USER1 -> USER2 -> USER3 -> USER0 -> USER1 -> USER2 -> USER3 -> USER0, and so on. This will give the illusion that light is traveling from USER0 to USER3 in loops. Type the following program in Cloud9, save it as danceLEDs.js and run it. The code for danceLEDs.js is as follows:

var b = require('bonescript');
var glowTime = 100;
var exitTime = 30000;
var tempTimer;

b.pinMode("USR0", b.OUTPUT);
b.pinMode("USR1", b.OUTPUT);
b.pinMode("USR2", b.OUTPUT);
b.pinMode("USR3", b.OUTPUT);

var exitTimer = setTimeout(exitProgram,exitTime);
glowUser0();

function glowUser0()
{
  b.digitalWrite("USR3", b.LOW);
  b.digitalWrite("USR0", b.HIGH);
  tempTimer = setTimeout(glowUser1,glowTime);
}

function glowUser1()
{
  b.digitalWrite("USR0", b.LOW);
  b.digitalWrite("USR1", b.HIGH...