Preface to the Third Edition The first edition of this book concentrated on a single chip that was widely used in hobby electronics and education e the PIC Ò 16F84A. This has now been superseded by chips that are faster, cheaper, and more complex and powerful. This has created a dilemma e whether to still use this chip that is effectively obsolete or substitute a current chip that is more complicated. In the end, I have done both e sticking with the '84 due to its relative simplicity in the initial stages, and then moving on to more recent chips with extra features, such as the 16F690. At the same time, I have taken advantage of simulation software that is now available, which provides on-screen animated circuits and user-friendly microcontroller program debugging. All the main points in this book are illustrated by simple examples, which are downloadable from the support website at www.picmicros.org.uk. Program source code can be modified, reassembled and retested using Microchip's MPLAB Ò IDE development system, downloadable free from www.microchip.com. This website also provides many of the technical references and data sheets used in the book. The schematic capture and simulation software is from Labcenter Electronics at www.labcenter.com. A demo version is available, but to create and test your own applications, a license will be needed. A low-cost package,