Julio Sanchez - Embedded Systems Circuits and Programming

EMBEDDEDSYSTEMS CIRCUITSandPROGRAMMING

Julio Sanchez

Minnesota State University, Mankato

Professor Emeritus

Maria P. Canton

Software Engineer, SKIPA Software Associates

CRC Press

Taylor & Francis Group

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Boca Raton, FL 33487-2742

2012 by Taylor & Francis Group, LLC

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Version Date: 20120224

International Standard Book Number: 978-1-4398-7904-7 (Hardback)

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Library of Congress Cataloging-in-Publication Data

Sanchez, Julio, 1938

Embedded systems : circuits and programming / Julio Sanchez, Maria P. Canton.

p. cm.

Includes bibliographical references and index.

ISBN 978-1-4398-7904-7 (hardcover : alk. paper)

1. Embedded computer systems--Design and construction. 2. Embedded computer systems--Programming. I. Canton, Maria P. II. Title.

TK7895.E42S263 2012

006.22--dc23

2012000494

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Table of Contents

Embedded systems are everywhere in our modern world. You can find them in automobiles, toys, kitchen appliances, computers, airplanes, TVs and digital recording devices, cell phones, gaming machines, nuclear power plants, space telescopes; in every electronic device that furnishes an intelligent, independent, or controllable functionality. By definition an embedded system is a computer designed to perform one or a few specialized functions, most often in real-time. The embedded system is usually a part of a hardware or mechanical device that includes other physical components. For example, a household dishwasher contains a cabinet with trays, one or more motors, sprayers and jets, deposits for holding soap and other chemicals, and an embedded computer system that determines cycles, modes, and timing of the device. It is this embedded controller that actually operates the machine, and what our book is about.

The authors conceived Embedded Systems: Circuits and Programming as a reference and a resource kit for engineers, scientists, and electronic enthusiasts who need to develop systems and boards that contain digital components and controls sometimes combined with analog devices. Our book is also intended as a tutorial on microcontroller programming and on the basics of embedded design. The focus is on the needs of working professionals in the fields of electrical, electronic, computer, and software engineering.

Many engineered products require the development of one or more embedded systems. At the commercial fabrication stage the embedded system or systems are re fined and optimized by specialists in order to facilitate production and minimize cost. However, during the development and prototyping phases, the developer often needs to create an embedded system that demonstrates the operation of the device, proves its viability, or exercises its functionality. This initial product is often called a prototype. The availability of off-the-shelf components, the abundance of design and prototyping tools, and the ease with which digital controllers can be programmed make it possible for the non-specialist to develop these boards and controllers. In this book we focus on the following development tools and resources:

The use of standard or off-the-shelf components such as input/output devices, integrated circuits, motors, and programmable microcontrollers

The development of circuit prototypes and their implementation using breadboards, followed by the in-house fabrication of test-time PCBs, and finalized by the manufactured board

The availability and use of development tools that facilitate the design and prototyping of embedded systems, such as electronic design programs and software utilities for creating printed circuit boards

Sample circuits that can be used as part of the targeted embedded system

The selection and programming of microcontrollers suitable for use in the circuit at hand

We have aimed at a book that is functional and hands-on. The resources furnished to the reader include sample circuits with their corresponding programs. The circuits are depicted and labeled clearly in a way that is easy to follow and reuse. For some critical circuits we provide tested PCB files. The sample programs are matched to the individual circuits but general programming techniques are also discussed in the text. There are appendices with hands-on information and the books online software package includes tools, resources, and code listings. These materials are available at

http://www.crcpress.com/product/isbn/9781439879047.

Julio Sanchez

Maria P. Canton

An embedded system can be defined as a computer system that performs one or more dedicated or specialized functions usually with Real-Time constraints. It is the digital controller that is embedded as part of system, which also includes other hardware and mechanical elements. A modern dishwasher contains an embedded control system. On the other hand, a general-purpose computer such as a PC is designed to meet a variety of user needs. The control system in the dishwasher does one task: wash dishes, while the PC on your desktop can be used in word processing, browsing the Web, balancing your checkbook, and many other applications.

Embedded systems are controlled by one or more digital ...

An electrical network is a collection of electrical elements that can include voltage sources, lines, connectors, resistors, inductors, capacitors, switches, controllers, and a host of other standard and special components. The