Book Image

Scratch 1.4: Beginner's Guide

Book Image

Scratch 1.4: Beginner's Guide

Overview of this book

If you have the imaginative power to design complex multimedia projects but can't adapt to programming languages, then Scratch 1.4: Beginner's Guide is the book for you. Imagine how good you'll feel when you drag-and-drop your way to interactive games, stories, graphic artwork, computer animations, and much more using Scratch even if you have never programmed before. This book provides teachers, parents, and new programmers with a guided tour of Scratch's features by creating projects that can be shared, remixed, and improved upon in your own lesson plans. Soon you will be creating games, stories, and animations by snapping blocks of "code" together. When you program you solve problems. In order to solve problems, you think, take action, and reflect upon your efforts. Scratch teaches you to program using a fun, accessible environment that's as easy as dragging and dropping blocks from one part of the screen to another. In this book you will program games, stories, and animations using hands-on examples that get you thinking and tinkering. For each project, you start with a series of steps to build something. Then you pause to put our actions into context so that you can relate our code to the actions on Scratch's stage. Throughout each chapter, you'll encounter challenges that encourage you to experiment and learn. One of the things you're really going to love is that, as you begin working through the examples in the book, you won't be able to stop your imagination and the ideas will stream as fast as you can think of them. Write them down. You'll quickly realize there are a lot of young minds in your home, classroom, or community group that could benefit from Scratch's friendly face. Teach them, please.
Table of Contents (17 chapters)
Scratch 1.4 Beginner's Guide
Credits
About the Author
About the Reviewer
Preface
Scratch Resources
Index

Capture sound input


We're going to create a quick program that switches the background when a sound is made.

Time for action – switch backgrounds on sound

Let's emulate night and day with our backgrounds so that each sound changes the scene. Open a new Scratch project and begin:

  1. Create the second background by copying the default white background. Then, edit background2 and use the fill tool to paint it black.

  2. Add the when flag clicked control block to the scripts area of the stage.

  3. Add a forever if block to the when flag clicked block.

  4. We need to evaluate the sound level before we act on it. From the Operators palette, add the greater than block.

  5. Now, let's evaluate the sound. From the Sensing palette, drag the sensor value block into the first field of the greater than block. Select the sound option from the drop-down list of options.

  6. We want to switch the background whenever the sound is greater than 0. Type a 0 in the second field of the greater than block so that the statement reads sound sensor...