Chapter 1
Introducing LEGO MINDSTORMS EV3

Did you get a box that looks like the one shown in Figure 1.1?

Figure 1.1 The LEGO MINDSTORMS EV3 set, item number 31313

If you did, you are ready to use this book. Several versions of the LEGO MINDSTORMS set are available, but throughout this book we use the LEGO MINDSTORMS EV3 set, which has a LEGO item number of 31313. This chapter provides a brief overview of the equipment in the set and what it does.

Understanding the EV3 Set: It Begins When You Open the Box

The EV3 set consists of various components. You may have seen some of the components in other LEGO sets, but even those familiar with the previous version of LEGO MINDSTORMS will find some parts that they have never seen. Before you use your new set, it is important to know what you have. The key components include the following:

• The electronic components that come with the EV3 set
• EV3 software
• TECHNIC building parts
• Building instructions
• A test board

By understanding the various components, you will be able to design your robot more efficiently. Let's take a look at these components in more detail.

EV3 Electronic Parts

One of the most important characteristics defining a robot is that it processes commands and generates movements. The electronic components that come with your EV3 set will enable you to build robots that process the commands that you write and generate movements that are defined in those commands.

The EV3 Brick

The EV3 brick, shown in Figure 1.2, acts like the robot's brain. Like the way that our brain tells our body what to do, the EV3 brick instructs a robot how to behave. The difference between our brain and the EV3 brick is that our brain behaves on its own, whereas the EV3 brick only interprets the programs that you write. Note that you will need six AA 1.5V batteries to run the EV3 brick.

Figure 1.2 The EV3 brick

Motors

You will program the EV3 motors, shown in Figure 1.3, to create the movements of your robot. Saying that the EV3 brick is the brain of a robot, the motors are like muscles. As our muscles generate all of our body movements, the motors will power all the actions of your robot such as driving, walking, lifting, spinning, and so on.

Figure 1.3 The EV3 Motors: The large motors and the medium motor

As you can see in Figure 1.3, the large and medium motors have quite different appearances. The large motor is bigger than the medium motor, and the body size represents the strength of the motor. Also, the two motors move in different directions: The large motor's movement is parallel with the body of the motor whereas the medium motor's movement is perpendicular with the body of the motor, which allows you to effectively design a robot that can achieve your goal.

Sensors

Within the EV3 set, you will find a touch sensor, a color sensor, and an infrared sensor (see Figure 1.4). As you build the projects from this book, you will learn to use these sensors to make your robots interactive. In other words, your robot will be able to decide its action based on the inputs from its surroundings. For example, let's say you have a vehicle type robot. With an infrared sensor, it can detect how far an object is in front of it. Based on the data from the sensor, the robot can play a louder sound when it gets closer to the object.

Figure 1.4 The EV3 sensors

Remote Infrared Beacon

The remote infrared beacon, or the IR beacon, is one of the cool new features of EV3 (see Figure 1.5). You can use it as a remote control for your robot, and you can program various commands for each button or combinations of buttons. In addition, you can set your robot to detect where the IR beacon is. Note that you should not use this device with the infrared sensor.

Figure 1.5 The remote infrared beacon

Cables

This set contains two types of cables (see Figure 1.6): connector cables and a USB 2.0 cable. Connector cables are for plugging the motors and sensors into the EV3 brick. The USB cable is used to download a program to the EV3 brick from your computer.

Figure 1.6 The connector cables and the USB 2.0 cable

EV3 Software

To give your EV3 robot instructions, you must use the EV3 software specifically designed for this set. If you are looking in the box for an installation disc, you will be looking for a while. LEGO offers its free EV3 software only as a download from www.LEGO.com/mindstorms. From the main page, click the Downloads link to display the page shown in Figure 1.7. Then click the Download button.

Figure 1.7 Downloading the EV3 software

Don't worry if you don't have the EV3 software available when you want to test out your robot. There is an app that comes with the brick that allows you to program your robot. The program that you can create with this app will be simpler than with the EV3 software, but it is still very useful! You will see where you can find this app on the brick when we go over the EV3 brick interface in “Building the Auto-Driver: A Starter Vehicle.”

Which Version Do I Download?

The EV3 software is compatible with both PC and Mac. If you use a Windows operating system, it should be one of the following versions: Windows XP (32-bit); Vista (32-/64-bit), excluding Starter Edition; Windows 7 (32-/64-bit); and Windows 8 desktop mode, excluding Starter Edition. If you use a Mac operation system, it should be one of the following versions: Mac OS X 10.6, 10.7, or 10.8 (Intel only).

The download page contains options for choosing the operating system (Mac OS X and Win32) and language. If you download the installation file for PC, you will see a file with a .exe extension; for Mac, it will be a .dmg file. After the file downloads to your computer, just double-click the file icon and follow the instructions that pop up on your screen.

TECHNIC Building Parts

Other than the electronic parts, the box contains various parts for building robots. Before jumping into building robots, let's overview some of the main building parts that you will use often and their important features.

Studless TECHNIC Beams

When building EV3 robots, you will use studless TECHNIC beams (see Figure 1.8). The official name is quite a mouthful, so from here on out we will just refer to the part as a beam. These parts are crucial for building complex, moving robots that would not be possible using standard LEGO bricks.

Figure 1.8 Various studless TECHNIC beams

Connector Pegs

The set contains many small parts, but the majority of the pieces look like the connector pegs shown in Figure 1.9. Note that they are also called connecter pins.

Figure 1.9 Different types of connector pegs

These components are called connector pegs because they allow multiple parts to snap together. Connector pegs come in different sizes with different features, but one of the important things that you need to know is how to distinguish the following: The connector peg and the connector peg with “friction.” If you look at the regular connector peg, its surface is smooth or “frictionless” (see Figure 1.10), whereas the connector peg with friction has little bumps on the surface.

Figure 1.10 Connector peg with friction versus a frictionless connector peg

If you put a connector peg on a beam, you will notice that the beam can be turned easily. However, if instead you use a connector peg with friction, it will be more difficult to turn the beam because the little bumps on the peg create more resistance.

Mechanical Pieces

When you design your robot's movements, the mechanical pieces allow for a more efficient construction (see Figure 1.11). These pieces provide, but are not limited to, mechanical advantages such as switching the direction of gear movement, building a drive train, changing the speed of gear movements, and so on.

Making an EV3 Organizer

The EV3 set comes with many different pieces. Based on my experience, I prefer to have all the parts organized separately as I design a robot. I can thus see what parts I have left at a glance and not lose my thought process by spending time searching for a piece. You can probably use plastic cups or small containers, but I highly recommend that you take as your EV3 organizer an organizer that is normally used for spare parts (see Figure 1.12). This way, you can keep parts organized by size or type and store everything all together. You can find these organizers at any well-stocked hardware store or on the Internet.

Figure 1.11 The EV3 mechanical pieces: spur gears, double bevel gears, worm gear, cam, and so on

Figure 1.12 Organize your EV3 set.

The Building Instructions and the Test Board

In addition to parts, the EV3 box also contains a booklet with building...