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

Program to read from push button


Write the following code in Cloud9 and save it as pushButton.js. Run the program, keep the button pressing and releasing. You should see Button is pressed printed when you press the button and Button is released when the button is released. The program will exit after a minute automatically.

var b = require('bonescript');var loopTime = 1000;
var exitTime = 60000;
var button = 'P8_16';
b.pinMode(button, b.INPUT);
var loopTimer = setInterval(check,loopTime);
var exitTimer = setTimeout(exitProgram,exitTime);

function check()
{
  b.digitalRead(button, checkButton);
}

function checkButton(pinObj)
{
  if(pinObj.value == b.HIGH)
  {
    console.log("Button is pressed");
  }
  else
  {
    console.log("Button is released");
  }
}

function exitProgram()
{
   clearInterval(loopTimer);
   console.log("Program exiting");
} 

Explanation

We first declared that we are going to use the P8_16 pin as the input. That means we will only read from it and not write on it. We set...