IN THIS CHAPTER

Inspecting the Arduino Uno

Discovering other Arduino boards

Knowing where to shop for Arduinos

Finding the right Arduino kit to get started

Setting up a workspace

Installing Arduino

Introducing Arduino Web Editor

The name Arduino encompasses a host of concepts. It can refer to an Arduino board, the physical hardware, the Arduino environment — that is, a piece of software that runs on your computer — and, finally, Arduino as a subject in its own right, as in this book: how the hardware and software can be combined with related craft and electronics knowledge to create a tool kit for any situation.

This chapter provides an overview of what you need to get started with Arduino. You may be eager to dive in, so you may want to quickly scan through this chapter, stopping at any areas of uncertainty and referring to them later as needed.

First, you learn about the components used on the Arduino Uno board, which is the starting point for most Arduinists. Beyond that, you get acquainted with the other available Arduino boards, how they differ, and what uses they have. The chapter lists major suppliers that can equip you with all the parts you need and examines some of the starter kits that are ideal for beginners and for accompanying this book. When you have the kit and a workspace, you’re ready to start.

Lastly, you find out where to obtain the software to control your Arduino. I walk you through the steps for downloading and installing the software, and give you a brief tour of the environment in which you develop your Arduino programs.

Getting to Know the Arduino Uno

No one definitive Arduino board exists; many types of Arduino boards are available, each with its own design to suit various applications. Deciding what board to use can be a daunting prospect because the number of boards is increasing, each with new and exciting prospects. However, one board can be considered the archetype of the Arduino hardware, the one that almost all people start with and that is suitable for most applications. It’s the Arduino Uno.

The most recent main board to date is the Arduino Uno R3 (released in 2011). Think of it as the plain vanilla of Arduino boards. It’s a good and reliable workhorse suitable for a variety of projects. If you're just starting out, the Uno R3 is the board for you (see Figures 2-1 and 2-2).

Uno is Italian for the number one, named for the release of version 1.0 of the Arduino software. Predecessors to this release had a variety of names, such as Serial, NG, Diecimila (10,000 in Italian, to mark that 10,000 boards had been sold), and Duemilanove (2009 in Italian, the release date of the board); the Uno has ushered in some much needed order to the naming of the boards. R3 relates to the revision of the features on the board, which includes updates, refinements, and fixes. In this case, it is the third revision.

The board has many small components, described throughout much of this chapter.

The Brains: ATmega328P microcontroller chip

You can think of the microcontroller chip itself as the brains of the board. The chip used in the Arduino Uno is the ATmega328P, made by Atmel. It’s the large, black component in the center of the board. This chip is known as an integrated circuit, or IC. It sits in a socket; if you were to remove it, it would look like the one shown in Figure 2-3.

This same chip can come in different forms, referred to as packages. The one in an Arduino Uno is in a plated-through hole, or PTH, package, named because of the way it makes contact with the board. Another variation you may find is the Arduino Uno SMD, or surface mount device, package, which is mounted on the surface of the board rather than in holes that go through it. This chip is much smaller, but it is not replaceable, whereas the PTH chip is. Apart from that, it functions exactly the same as the PTH and differs only in looks.

Header sockets

The microcontroller socket connects all the legs of the ATmega328 microcontroller chip to other sockets, referred to as header sockets, which are arranged around the edge of the board and are labeled for ease of use. These black sockets are divided into three main groups: digital pins, analog input pins, and power pins.

All these pins transfer a voltage, which can be either sent as output or received as an input. Why are these pins important? They allow you to connect additional circuitry to the board quickly and easily when prototyping with a breadboard (described in Chapter 6) and to design additional boards, called shields, that fit neatly on top of your Arduino board (see Chapter 12 for more on shields).

This same process of sending and receiving electrical signals is going on inside modern computers. But because they are so advanced and refined compared to a humble Arduino, it is difficult to directly link a computer accustomed to digital signals (0s and 1s) to an electronic circuit that deals with a range of voltages (0v to 5v in the ATmega328P’s case).

The Arduino (see the sketch in Figure 2-4) is special because it can interpret these electric signals and convert them to digital signals that your computer can understand — and vice versa. It also enables you to write a program using software on a conventional computer that the Arduino IDE (integrated development environment) converts or compiles to electrical signals that your circuit can understand.

By bridging this gap, it is possible to use a conventional computer's benefits — ease of use, user-friendly interfaces, and code that is easy for humans to understand — to control a wide range of electronic circuits and even give them complex behaviors with relative ease.

Discovering Other Arduino Boards

The preceding section describes the standard USB Arduino board, but you should be aware that many others exist, all designed with different needs in mind. Some offer more functionality, and others are designed to be more minimal, but generally they follow a design similar to that of the Arduino Uno. For this reason, all examples in this book are based on the Uno.

Previous revisions of the Uno should work without any changes, but if you're using an older or more specialized board, be sure to follow instructions specific to it. This section gives you a brief rundown of other available boards.

Shopping for Arduino

Initially, Arduino boards were available only from a small number of hobby shops scattered across the world. Now you have lots of places to purchase an Arduino, as listed in the following sections. Later in this chapter, I tell you about beginner’s kits, which pull together the basic components for you; I recommend a kit to get you started on your Arduino endeavors.

On the Arduino site, you can find an exhaustive list of Arduino resellers and manufacturers around the world (store.arduino.cc/distributors). Here are just a few of the most useful.

Kitted Out: Starting with a Beginner’s Kit

By this point, you probably know a bit about the Arduino board, but no board is an island; you need lots of other bits so that you can make use of the board. In the same way that a computer is of no use without a mouse and keyboard, an Arduino is of no use — or at least not as much fun — without components.

Every new Arduinist should follow several basic examples to learn the fundamentals of Arduino (which this book covers in Chapters 3 through 7). These examples are all achievable with a few basic components. To save you the time and effort of finding these components, a few enterprising individuals and companies have put together kits that let you experiment in no time!

Many kits have been designed by different individuals and companies based on their experiences, likes, and dislikes. You can also find a lot of components that do the same job but have different appearances, based on their application.

The following short list describes a few core components that should be included in all good Arduino beginners’ kits:

• Arduino Uno: This is the board you know and love.
• USB A-B cable: This cable is essential to make use of your Arduino. It can also be found on printers and scanners.
• LEDs: Light-emitting diodes in various colors are great for providing visual feedback for your project as well as for testing lighting projects on a small scale.
• Resistors: Also referred to as fixed resistors, these are fundamental electrical components used to resist the flow of current through a circuit. Resistors are essential for the smooth running of most circuits. Each resistor has a fixed value, which is indicated by a colored band on the side of the resistor. These bands help you to quickly identify a resistor’s resistance visually.
• Variable resistors: Also known as potentiometers or pots, variable resistors resist current in the same way as fixed-value resistors, but they can change their resistance. They are most commonly used in radios and hi-fi equipment for tuning and volume control dials, and are available also in other housings to detect other inputs such as force or flex on a surface.
• Diodes: Also known as rectifier diodes, diodes are similar to LEDs but without the light. They have an extremely high resistance to the flow of current in one direction and an extremely low (ideally zero) resistance in the other, which is the same reason that an LED works in only one direction. Instead of emitting light like LEDs, diodes control the flow of current throughout your circuit.
• Photo diodes: Also known as photo resistors or light-dependent resistors (LDRs), photo diodes change their resistance when light falls on them. They can have a variety of different uses depending on how they’re placed relative to the light source.
• Pushbuttons: These components are found behind the scenes in many bits of consumer electronics such as game console controllers and stereos. They’re used to either connect or disconnect parts of a circuit so that your Arduino can monitor human inputs.
• Temperature sensors: These sensors tell you what the ambient temperature is wherever they are placed. They are great for observing changes in your environment.
• Piezo buzzer: A piezo buzzer is technically described as a discrete sounding device. These simple components can be supplied with a voltage to produce simple notes or music. They can also be attached to surfaces to measure vibrations.
• Relays: These electrically operated switches are used to switch higher power circuits using your low-voltage Arduino. Half of a relay is an electromagnet, and the other half is a magnetic switch. The electromagnet can be activated by the 5V of the Arduino, which moves the contact of the switch. Relays are essential for bigger lighting and motor-based projects.
• Transistors: These components are the basis for all modern computers. Transistors are electrically operated switches, similar to relays, but the switch happens on a chemical level rather than a physical level. This means that the switching can be super fast, making transistors perfect for high-frequency operations such as animating LED lighting or controlling the speed of motors.
• DC motors: These motors are simple electric motors. When electric current is passed through a motor, it spins in one direction; when that direction is reversed, it spins in the other. Electric motors come in great variety, from those in your phone that vibrate to those in electric drills.
• Servo motors: These motors have on-board circuitry that monitors their rotation. Servo motors are commonly used for precision operations such as the controlled opening of valves or moving the joints of robots.

Here are a few of the better-known kits, ascending in price. They include all the components in the preceding list, and any will be an excellent companion for the examples in this book:

• Arduino Starter Kit from Arduino, available from store.arduino.cc/usa/arduino-starter-kit, costing $87.90 at the time of this writing
• Starter Kit for Arduino (ARDX) by Oomlout, available from www.adafruit.com/products/170, costing $84.95 at the time of this writing
• SparkFun Inventor’s Kit 4.0 by SparkFun, available from www.sparkfun.com/products/14265, costing $99.95 at the time of this writing

You can create all the basic examples in this book with any kit in the preceding list, although a slight variation may occur in the number and type of components. See an example Arduino kit in Figure 2-5. Sometimes the same component can take many different forms, so be sure to carefully read the parts list to make sure that you can identify each of the components before you start. Cheaper kits are available, but these will likely not include some components, such as motors or the variety of sensors.

Preparing a Workspace

When working on an Arduino project, you could sit on your sofa or be at the top of a ladder. I’ve been there before! But just because it’s possible to work this way doesn’t mean that it’s sensible or advisable. You’re far better off to have a good workspace before you dive into your experiment, especially when you're just starting out with Arduino.

Working with electronics is a fiddly business. You’re dealing with lots of tiny, delicate, and very sensitive components, so you need great precision and patience when assembling your circuit. If you’re in a dimly lit room trying to balance things on your lap, you'll quickly go through your supply of components by either losing or destroying them.

It’s always good to make life easy for yourself, and the best way to do this when working on Arduino projects is to prepare your workspace. The ideal workspace has the following:

• Large, uncluttered desk or table
• Good work lamp
• Comfortable chair
• Cup of tea or coffee (recommended)

After you’re comfortable, you're ready to learn how to set up the Arduino software. The Arduino software is a type of an integrated development environment (IDE), a tool common in software development that allows you to write, test, and upload programs. Versions of Arduino software are available for Windows, macOS, Linux, and Arduino Web Editor.

Installing Arduino

This section talks you through installing the Arduino environment on your platform of choice. These instructions are specifically for installation using an Arduino Uno, but also work just as well for previous boards.

Arduino is free to download from www.arduino.cc/en/main/software and is supported on macOS, Windows 32-bit and 64-bit, and Linux 32-bit, 64-bit, and ARM. At the time of this writing, Arduino was version 1.8.4.

To install Arduino, do the following:

• On a Mac: The .zip file unzips automatically, producing the Arduino app file, which you can then drag to your Applications folder. From there, you can drag Arduino to the dock for easy access or create a desktop alias.
• On Windows: Download the installer file and double-click to install the file in a directory of your choice. You also have the option to create shortcuts and install the latest USB drivers.
• On Linux: Download the compressed file for your version of Linux and extract the package. Open the Arduino folder (whose name includes the version number, such as arduino-1.8.4) created by the extraction process and find the install.sh file. Right-click it and choose Run in Terminal from the contextual menu.

Surveying the Arduino Environment

Programs written for Arduino are known as sketches. This naming convention was passed down from Processing, which allowed users to create programs quickly, in the same way that you would scribble an idea in a sketchbook.

Before you look at your first sketch, I encourage you to explore the Arduino software. The Arduino software is an integrated development environment, or IDE, and this environment is presented to you as a graphical user interface, or GUI (pronounced “goo-ey”).

A GUI provides a visual way of interacting with a computer. Without it, you would need to read and write lines of text, similar to what you may have seen in the DOS prompt in Windows, Terminal in macOS, and in that bit about the white rabbit at the start of The Matrix.

The turquoise window is Arduino’s GUI. It’s divided into the following four main areas (labeled in Figure 2-6):

• Menu bar: Similar to the menu bar in other programs you’re familiar with, the Arduino menu bar contains drop-down menus to all the tools, settings, and information that are relevant to the program. In macOS, the menu bar is at the top of your screen; in Windows and Linux, the menu bar is at the top of the active Arduino window.
• Toolbar: The toolbar contains several buttons that are commonly needed when writing sketches for Arduino. These buttons, which are also available on the menu bar, perform the following functions:
  • Verify: Checks that your code makes sense to the Arduino software. Known as compiling, this process is a bit like a spelling and grammar checker. Be aware, however, that although the compiler checks that your code has no obvious mistakes, it does not guarantee that your sketch works correctly.
  • Upload: Sends your sketch to a connected Arduino board. It automatically compiles your sketch before uploading it.
  • New: Creates a sketch.
  • Open: Opens an existing sketch.
  • Save: Saves the current sketch.
  • Serial monitor: Allows you to view data that is being sent to or received by your Arduino board.
• Text editor: This area displays your sketch as text. It is almost identical to a regular text editor but has a few added features. Some text is color coded if the Arduino software recognizes it. You also have the option to auto-format the text so that it is easier to read.
• Message area: Even after years of using Arduino, you’ll still make mistakes (everybody does), and the message area is the first way for you to find out that something is wrong. (Note: The second way is the smell of burning plastic.)

Using Arduino Web Editor

Arduino Web Editor is a cloud-based version of the downloadable IDE and a great way to get started quickly.

Cloud-based means that Web Editor runs in your browser and saves your project files to your online account instead of on your computer. Apart from those differences, Web Editor has all the core features of the downloadable IDE but is more flexible, working across platforms without the need to install any files. In Figure 2-7, you can see how the layout differs.