Book excerpt: Learn how to create functional gadgets using simple but clever circuits based on the venerable "555." These projects will give you hands-on experience with useful, basic circuits that will aid you across other projects. These inspiring designs might even lead you to develop the next big thing. The 555 Timer Oscillator Integrated Circuit chip is one of the most popular chips in the world. Through clever projects, you will gain permanent knowledge of how to use the 555 timer will carry with you for life. With this book you'll build a series of unique and useful projects. Each one gets more and more complicated, and you'll learn more as you go along. Start off with a basic 555 timer IC design concept to build a simple project. Learn how to create a simple form of digital memory that can store data, the basis of every computer system ever created. Build a collection of lighting effect circuits that will flash and animate LEDs in different ways. Use a simple configuration of the 555 timer IC to create a complex traffic light system. You'll even create sound with an audio synthesizer! No programming is needed to make startlingly functional electronic devices. Get started today building the next big thing. Or even the next small thing. But build some thing! What You Need: The only physical things people need are the parts to build the projects, which are labeled out with part numbers in the beginning of each project. Otherwise, only an hour here or there is needed to build these projects. Only some familiarity with electrical components is necessary in regards to purchasing for each project.