Arduino For Dummies

Chapter 1

What Is Arduino and Where Did It Come From?

In This Chapter

Discovering Arduino

Learning where Arduino came from and why it’s so important

Introducing the basic principles

Arduino is made up of both hardware and software.

The Arduino board is a printed circuit board (PCB) that is specifically designed to use a microcontroller chip as well as other input and outputs. It also has many other electronic components that are needed for the microcontroller to function or to extend its capabilities.

Microcontrollers are small computers contained within a single, integrated circuit or computer chip, and they are an excellent way to program and control electronics. Many devices, referred to as microcontroller boards, have a microcontroller chip and other useful connectors and components that allow a user to attach inputs and outputs. Some examples of devices with microcontroller boards are the Wiring board, the PIC, and the Basic Stamp.

You write code in the Arduino software to tell the microcontroller what to do. For example, by writing a line of code, you can tell an LED to blink on and off. If you connect a pushbutton and add another line of code, you can tell the LED to turn on only when the button is pressed. Next, you may want to tell the LED to blink only when the pushbutton is held down. In this way, you can quickly build a behavior for a system that would be difficult to achieve without a microcontroller.

Similarly to a conventional computer, an Arduino can perform a multitude of functions, but it’s not much use on its own. It requires other inputs or outputs to make it useful. These inputs and outputs allow a computer to sense objects in the world and to affect the world.

Before you move forward, it might help you to understand a bit of the history of Arduino.

Where Did Arduino Come From?

Arduino started its life in Italy, at Interaction Design Institute Ivera (IDII), a graduate school for interaction design. This is a specific school of design education that focuses on how people interact with digital products, systems, and environments and how they in turn influence us.

The term interaction design was coined by Bill Verplank and Bill Moggridge in the mid-1980s. The sketch in Figure 1-1 by Verplank illustrates the basic premise of interaction design. This diagram is an excellent illustration of how the process of interaction works: If you do something, you feel a change, and from that you can know something about the world.

Although it is a general principle, interaction design more commonly refers to how we interact with conventional computers by using peripherals, such as mice, keyboards, and touchscreens, to navigate a digital environment that is graphically displayed on a screen.

Courtesy of Bill Verplank

Figure 1-1: The principle of interaction design, illustrated by Bill Verplank.

There is another avenue, referred to as physical computing, which is about extending the range of these computer programs, software, or systems. Through electronics, computers can sense more about the world and have a physical impact on the world themselves.

Both of these areas — interaction design and physical computing — require prototypes to fully understand and explore the interactions, which presented a hurdle for nontechnical design students.

In 2001, a project called Processing that was started by Casey Reas and Benjamin Fry aimed to get nonprogrammers into programming by making it quick and easy to produce onscreen visualizations and graphics. The project gave the user a digital sketchbook on which to try ideas and experiment with a very small investment of time. This project in turn inspired a similar project for experimenting in the physical world.

Building on the same principles as Processing, in 2003 Hernando Barragán started developing a microcontroller board called Wiring. This board was the predecessor to Arduino.

In common with the Processing project, the Wiring project also aimed to involve artists, designers, and other nontechnical people, but Wiring was designed to get people into electronics rather than programming. The Wiring board (shown in Figure 1-2) was less expensive than some other microcontrollers, such as the PIC and the Basic Stamp, but it was still a sizable investment for students to make.

Figure 1-2: An early Wiring board.

In 2005, the Arduino project began in response to the need for affordable and easy-to-use devices for Interaction Design students to use in their projects. It is said that Massimo Banzi and David Cuartielles named the project after Arduin of Ivera, an Italian king, but I’ve heard from reliable sources that it also happens to be the name of the local pub near the university, which may have been of more significance to the project.

The Arduino project drew from many of the experiences of both Wiring and Processing. For example, an obvious influence from Processing is the graphic user interface (GUI) that is used in the Arduino software. This GUI was initially “borrowed” from Processing, and even though it still looks similar, it has since been refined to be more specific to Arduino. I cover the Arduino interface in more depth in Chapter 4.

Arduino also kept the naming convention from Processing, naming its programs sketches. In the same way that Processing gives people a digital sketchbook to create and test programs quickly, Arduino gives people a way to sketch out their hardware ideas as well. Throughout this book, I show many sketches that allow your Arduino to perform a huge variety of tasks. By using and editing the example sketches in this book, you can quickly build up your understanding of how they work and will be writing your own in no time. Each sketch is followed with a line-by-line explanation of how it works to ensure that no stone is left unturned.

The Arduino board, shown in Figure 1-3, was made to be more robust and forgiving than Wiring or other earlier microcontrollers. It was not uncommon for students and professions, especially those from a design or arts background, to break their microcontroller within minutes of using it, simply by getting the wires the wrong way around. This fragility was a huge problem, not only financially but also for the success of the boards outside technical circles.

It is also possible to change the microcontroller chip on an Arduino, so if it is damaged, you can just replace the chip rather than the whole board.

Another important difference between Arduino and other microcontroller boards is the cost. In 2006, another popular microcontroller, the Basic Stamp, cost nearly four times as much (http://blog.makezine.com/2006/09/25/arduino-the-basic-stamp-k/) as an Arduino, and even today, a Wiring board still costs nearly double the price of an Arduino.

In one of my first Arduino workshops, I was told that the price was intended to be affordable for students. The price of a nice meal and a glass of wine at that time was about 30 euros, so if you had a project deadline, you could choose to skip a nice meal that week and make your project instead.

The range of Arduino boards on the market is a lot bigger than it was back in 2006. In Chapter 2, you learn about just a few of the most useful Arduino and Arduino-compatible boards and how they differ to provide you with a variety of solutions for your own projects. Also, in Chapter 13 you learn all about a special type of circuit board called a shield, which can add useful, and in some cases phenomenal, features to your Arduino, turning it into a GPS receiver, a Geiger counter, or even a mobile phone, to name just a few.

Figure 1-3: The original Arduino Serial board.

Learning by Doing

People have used technology in many ways to achieve their own goals without needing to delve into the details of electronics. Following are just a few related schools of thought that have allowed people to play with electronics.

Patching

Patching isn’t just a town in West Sussex; it is also a technique for experimenting with systems. The earliest popular example of patching is in phone switchboards. For an operator to put you through to another line they had to physically attach a cable. This was also a popular technique for synthesizing music, such as with the Moog synthesizer.

When an electronic instrument generates a sound, it is really generating a voltage. Different collections of components in the instrument manipulate that voltage before it is outputted as an audible sound. The Moog synthesizer works by changing the path that that voltage takes, sending it through a number of different components to apply different effects.

Because so many combinations are possible, for the musician the experience is largely based on trial and error. But the simple interface means that this process is extremely quick and requires very little preparation to get going.

Hacking

Hacking is popular term and is commonly used to refer to subversive people on the Internet. More generally, though, it refers to exploring systems and making full use of them or repurposing them to suit your needs.

Hacking in this sense is possible in hardware as well as software. A great example of hardware hacking is a keyboard hack. Say that you want to use a big, red...