| By Brad Kendall |
| http://www.bradkendall.ca/ |
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| Published August 2013 |
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| share: |
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| This manual is the intellectual property of MakeUseOf. It must only be published in its original form. Using |
| parts or republishing altered parts of this guide is prohibited without permission from MakeUseOf.com |
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| Think you’ve got what it takes to write a manual for MakeUseOf.com? We’re always willing to hear a pitch! |
| Send your ideas to justinpot@makeuseof.com. |
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| Table Of Contents |
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| 1. Intro to the Arduino |
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| 2. What Can You Do With an Arduino? |
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| 3. What Is Inside an Arduino? |
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| 4. What You Will Need For This Guide |
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| 5. Electrical Component Overview |
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| 5.1 What is a Breadboard? |
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| 5.2 What is an LED? |
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| 5.3 What is a Photo Resistor? |
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| 5.4 What is a Tactile Switch? |
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| 5.5 What is a Piezo Speaker? |
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| 5.6 What is a Resistor? |
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| 5.7 What are Jumper Wires? |
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| 6. Programming Overview |
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| 6.1 Variables |
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| 6.2 Functions |
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| 6.3 Logic Overview |
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| == - The Equals operator |
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| && - The AND operator |
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| || - The OR operator |
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| ! - The NOT operator |
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| Using Multiple Expressions |
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| 7. Setting Up Your Arduino |
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| 7.1 Installing the Arduino IDE on Windows |
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| Step 1: Download the Arduino software |
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| Step 2: Install the software |
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| 7.2 Installing the Arduino IDE on Mac OS X |
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| Step 1: Download the Arduino software |
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| Step 2: Install the software |
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| 7.3 Installing the Arduino IDE on Ubuntu/ Linux |
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| 7.4 Running the Arduino Software |
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| HTTP://MAKEUSEOF.COM |
| BRAD KENDALL, HTTP://WWW.BRADKENDALL.CA |
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| GETTING STARTED WITH ARDUINO |
| 8. Starter Projects |
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| 8.1 Communicating Between Your Arduino and Your PC |
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| Reading from the Serial Port |
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| 8.2 Building a Calculator |
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| 8.3 Turning on an LED |
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| 8.4 Making Your LED Blink |
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| 8.5 Making Multiple LEDs Blink |
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| 8.6 Pushbuttons with a Pull-up Resistor |
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| 8.7 Turning on an LED with a Pushbutton |
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| 8.8 Control an LED’s Brightness |
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| 8.9 Observing Light with your Arduino |
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| 8.10 Making Music with your Arduino |
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| 9. Where to go From Here |
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| HTTP://MAKEUSEOF.COM |
| BRAD KENDALL, HTTP://WWW.BRADKENDALL.CA |
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| GETTING STARTED WITH ARDUINO 1. Intro to the Arduino |
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| Arduino is an open-source electronics prototyping platform based on flexible, easy-to use hardware and software. It’s |
| intended for artists, designers, hobbyists, and anyone interested in creating interactive objects or environments. |
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| Arduino can sense the environment by receiving input from a variety of sensors and can affect its surroundings by |
| controlling lights, motors, and other actuators. The microcontroller on the board is programmed using the Arduino |
| programming language and the Arduino Development Environment. Arduino projects can be stand-alone, or they can |
| communicate with software running on a computer. |
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| There are plenty of other microcontrollers available. So you may be asking, why choose the Arduino? Arduino really |
| simplifies the process of building projects on a microcontroller making it a great platform for amateurs. You can easily |
| start working on one with no previous electronics experience. |
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| That is what this guide is about. |
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| In addition to Arduino’s simplicity, it is also inexpensive, cross-platform and open source. The Arduino is based on |
| Atmel’s ATMEGA8 and ATMEGA168 microcontrollers. The plans for the modules are published under a Creative Com- |
| mons license, so experienced hobbyists and professionals can make their own version of the Arduino, extending it and |
| improving it. |
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| Believe it or not, even relatively inexperienced users can build a version of the Arduino module on a breadboard in |
| order to understand how it works and save a little bit of money. |
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| 2. What Can You Do With an Arduino? |
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| There is a lot you can do with an Arduino. An Arduino can basically do anything by interfacing sensors with a com- |
| puter. This would allow you to take any sensor and have any action applied with the readings. For example (in one of |
| our projects) we will read the level of light in a room and adjust an LED’s brightness to react based on that input. This |
| of course is a simple example of what you can do with an Arduino. A more complicated example would be to read from |
| multiple sensors and use that data to affect other outputs. Think of the possibility of wiring your house with all sorts |
| of different sensors (photocells, oxygen sensors, thermometers) and having it adjust your blinds, air conditioner and |
| furnace and make your house a more comfortable place. |
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| Hackers have used Arduinos to create some amazing electronics projects. Things like: |
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| • Robots |
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| • Breathalyzers |
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| • Remote controlled cars |
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| 3d printers |
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| • Video games |
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| • Home automation systems |
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| And much more. Read about more great examples of Arduino projects. |
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| 3. What Is Inside an Arduino? |
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| Although there are many different types of Arduino boards available, this manual focuses on the Arduino Uno. This is |
| the most popular Arduino board around. So what makes this thing tick? Here are the specifications: |
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| • Processor: 16 Mhz ATmega328 |
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| • Flash memory: 32 KB |
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| • Ram: 2kb |
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| • Operating Voltage: 5V |
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| Input Voltage: 7-12 V |
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| • Number of analog inputs: 6 |
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| • Number of digital I/O: 14 (6 of them pwm) |
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| The specs may seem meager compared to your desktop computer, but remember that the Arduino is an embedded |
| device. We have a lot less to process than your desktop. |
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| Another wonderful feature of the Arduino is the ability to use what are called “Shields”. Although we will not be cov- |
| ering shields in this manual, an Arduino shield will give you crazy functionality like you wouldn’t believe. Check out |
| this list of some really cool Arduino shields to take your projects to the next level. |
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| 4. What You Will Need For This Guide |
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| Below you will find a shopping list of the components we will use for this manual. All these components should come |
| in under $50.00 USD. This should be enough to give you a good understanding of basic electronics and have enough |
| components to build some pretty cool projects. |
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| 1x Arduino Uno Microcontroller |
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| 1 x USB A-B Cable (same as your printer takes) |
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| 1x Breadboard |
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| 2 x LEDs |
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| 1 x Photo Resistor |
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| 1 x Tactile Switch |
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| 1 x Piezo Speaker |
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| 1 x 10 k-Ohm Resistors |
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| 1 x 2 k-Ohm Resistors |
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| 2 x 1 K-Ohm Resistors |
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| 1 x Jumper Wire Kit |
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| 5. Electrical Component Overview |
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| 5.1 What is a Breadboard? |
| Breadboards are blocks of plastic with holes into which wires can be inserted. The holes are connected electrically, so |
| that wires stuck in the connected holes are also connected electrically. |
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| The connected holes are arranged in rows, in groups of five, so that up to five parts can be quickly connected just by |
| plugging their leads into connected holes in the breadboard. When you want to rearrange a circuit, just pull the wire or |
| part out of the hole, and move it or replace it. The breadboard I recommended also includes power and ground lanes |
| on each side for easy power management. |
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| 5.2 What is an LED? |
| An LED, short for Light Emitting Diode, is a semiconductor light source. LEDs are typically used as visual indicators. |
| For instance, your new Arduino microcontroller has an LED on pin 13 that we frequently use to indicate an action or |
| event. |
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| 5.3 What is a Photo Resistor? |
| A photo resistor allows us to measure light by decreasing its resistance when it detects an increase of light intensity. |
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| 5.4 What is a Tactile Switch? |
| A tactile switch is an electric switch that controls the flow of electricity. When pressed, the switch completes the circuit. |
| Basically, it is a button. |
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| 5.5 What is a Piezo Speaker? |
| A piezo speaker is a single frequency beeper that converts an electrical signal into a tone. This will allow your Arduino |
| to sing to you. |
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| 5.6 What is a Resistor? |
| A resistor is an electrical component that limits or regulates the flow of electricity. |
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| 5.7 What are Jumper Wires? |
| Jumper wires are short wires that are used for prototyping circuits. These are what you will use to connect the various |
| components electrically to your Arduino. |
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| 6. Programming Overview |
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| If you’re not too familiar with programming, this guide should get you used to some of the fundamentals. If you’d like to |
| learn more about Arduino-specific functions, http://www.arduino.cc/en/Reference/HomePage is an excellent resource. |
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| 6.1 Variables |
| A variable is defined as a quantity that can assume any of a set of values. In the Arduino programming language, vari- |
| ables have types associated with them, which provide the set of valid values the variable can hold. Some languages |
| are not strict and allow a variable to hold nearly anything, but that is out of the scope of this manual. |
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| For example, a variable with type ‘int’ can only hold integer values like 1 or 12, and not 12.5 or “cats”. Unfortunately, |
| no variable is capable of holding a cat, something the programming world is quite upset about. |
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| Variables are an excellent resource, as they improve code readability and reuse, and are extremely convenient for use |
| as temporary storage. |
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| Before using a variable, you must declare it. This merely lets the Arduino compiler know what data type your variable |
| will hold. |
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| An example of a variable declaration is as follows: |
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| int itemCount; |
| In this case, the variable will be of type int, and therefore will only accept integers. |
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| Here are a few example assignments and operations. |
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| itemCount = 4; itemCount = itemCount + 8; // itemCount now holds the value 12. itemCount = |
| “10”; // This will not compile. |
| 6.2 Functions |
| A function is essentially a group of instructions that perform a specific task. There are many built-in functions, such as |
| digitalWrite() or tone(). In those cases, you don’t necessarily have to see the code, but can still reap the benefits. You |
| can also specify your own functions. |
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| The general form of a function is: |
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| [return type] [function name] ({arguments}) { [ Code to execute ] } |
| Note that functions can return data, as illustrated by the function having a return type. |
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| In many cases, there is no data to return, and in that case, the keyword ‘void’ would be used. |
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| The function name is a user-friendly ‘handle’ to reference later (digitalWrite would be the function name for the digi- |
| talWrite function). |
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| A function can accept zero or more arguments. Each argument must be of the form [datatype] [identifier]. For exam- |
| ple, if we called a function foo as such: |
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| foo(10); |
| The function header for foo would have to look like: |
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| void foo(int number) { } |
| In the function, code can reference ‘number’ to retrieve the passed value. Outside of the function, ‘number’ would be |
| undefined. |
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| Say we want to write a function to multiply two numbers, for whatever reason. This function would look like: |
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| int multiply(int num1, int num2) { int result; result = num1 * num2; return result; } |
| Note that this could simply look like: |
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| int multiply(int num1, int num2) { return num1 * num2; } |
| It’s usually a good idea to be liberal with the use of spaces, as it makes for much easier debugging. To each their own, |
| however. |
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| 6.3 Logic Overview |
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| You’ll often find yourself wanting to execute certain code under certain conditions. This will give you a quick overview |
| of the logical operators you have to work with. |
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| First up, with the exception of the NOT operator, each logical operation takes two operands. |
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| == - The Equals operator |
| This operator ensures that both operands are equal to one another. To test whether or not the operands are not equal |
| to one another, use the != (not-equals) operator. |
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| Example: |
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| 4 == 4 (true) 4 == 5 (false) 4 != 5 (true) |
| && - The AND operator |
| The AND operator is quite similar to the equals operator, except it does not evaluate to true when both operands are |
| false. |
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| For example: (true && true) evaluates to true, while (true && false) and (false && false) both evaluate to false. |
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| || - The OR operator |
| The OR operator will evaluate to true so long as at least one of the two operands is true. |
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| The only time OR will evaluate to false is if both the operands are false. |
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| ! - The NOT operator |
| This simply flips the truthiness of the operand specified. !false == true. |
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| Using Multiple Expressions |
| Sometimes you’d like to have more than one test. Fortunately, since (as above), something like (false == true) will |
| evaluate to false, nesting statements in brackets works, and the statements in brackets will be evaluated first. |
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| For example: |
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| if (( a != b) && (b > 12)) |
| a != b and b > 12 will have to be evaluated first, as their outcome determines whether the entire logical expression is |
| true. |
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| The past two sections should have given you enough basic knowledge to get started with our projects below. If it all |
| seems a little complicated, don’t worry. It will make a lot more sense when we apply it in a practical sense. |
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| 7. Setting Up Your Arduino |
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| Before we can start on our projects, we first need to get your Arduino talking to your computer. We need to do this so |
| you can compile and send code for your Arduino to execute. |
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| 7.1 Installing the Arduino IDE on Windows |
| Step 1: Download the Arduino software |
| Go to http://arduino.cc/en/Main/Software and download the Arduino Software for your Windows. |
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| Step 2: Install the software |
| Install the Drivers: |
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| • Plug in your board and wait for Windows to begin its driver installation process. After a few mo- |
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| ments, the process will fail, despite its best efforts. |
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| • Click on the Start Menu, and open up the Control Panel. |
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| • While in the Control Panel, navigate to System and Security. Next, click on System. Once the |
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| System window is up, open the Device Manager. |
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| Look under Ports (COM & LPT). You should see an open port named “Arduino UNO (COMxx)”. |
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| • Right click on the “Arduino UNO (COMxx)” port and choose the “Update Driver Software” option. |
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| • Next, choose the “Browse my computer for Driver software” option. |
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| • Finally, navigate to and select the Uno’s driver file, named “ArduinoUNO.inf”, located in the “Driv- |
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| ers” folder of the Arduino Software download. |
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| • Windows will finish up the driver installation from there. |
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| 7.2 Installing the Arduino IDE on Mac OS X |
| Step 1: Download the Arduino software |
| Go to http://arduino.cc/en/Main/Software and download the Arduino Software for your Mac OS X. |
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| Step 2: Install the software |
| The disk image (.dmg) should mount automatically. If it doesn’t, double-click it. It should look like the following image. |
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| Copy the Arduino application into the Applications folder (or elsewhere on your computer). Since you’re using an Ar- |
| duino Uno, you don’t have any drivers to install. |
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| 7.3 Installing the Arduino IDE on Ubuntu/ Linux |
| Install gcc-avr and avr-libc from the Terminal. |
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| sudo apt-get install gcc-avr avr-libc |
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| If you don’t have openjdk-6-jre already, install and configure that too: |
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| sudo apt-get install openjdk-6-jre sudo update-alternatives --config java |
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| Select the correct JRE if you have more than one installed. |
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| Go to http://arduino.cc/en/Main/Software/ and download the Arduino Software for Linux. You can untar and run it with |
| the following command: |
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| tar xzvf arduino-x.x.x-linux64.tgz cd arduino-1.0.1 ./arduino |
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| 7.4 Running the Arduino Software |
| Now that our software is installed and our Arduino is setup, let’s verify everything is working. The easiest way to do |
| this is by using the “Blink” sample application. |
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| 1. Open the Arduino Software by Double-clicking the Arduino Application (./arduino on Linux). |
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| 2. Make sure the board is still connected to your computer. |
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| 3. Open the LED blink example sketch: File > Examples > 1.Basics > Blink. You should see the |
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| code for the application open and it should look like this: |
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| 4. You’ll need to select the entry in the Tools > Board menu that corresponds to your Arduino. Se- |
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| lect the Arduino Uno Option. |
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| 5. Select the serial device of the Arduino board from the Tools > Serial Port menu. On Windows, |
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| This is likely to be COM3 or higher. On the Mac or on Linux, this should be something with ‘/dev/ |
| tty.usbmodem ‘ in it. |
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| 6. Now, simply click the “Upload” button in the environment. Wait a few seconds - you should see |
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| the RX and TX LEDs on the Arduino flashing. If the upload is successful, the message “Done up- |
| loading.” will appear in the status bar. |
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| A few seconds after the upload finishes, you should see the pin 13 (L) LED on the board start to blink. If it does, con- |
| gratulations! You’ve got your Arduino up and running. |
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| 8. Starter Projects |
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| Okay, now is when the real fun begins. Let’s get started. |
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| 8.1 Communicating Between Your Arduino and Your PC |
| Most of the communication you’ll be doing with the Arduino (for now) will be done via the Serial port (The USB cord). |
| This is quite trivial to set up on the Arduino. Merely add the following line to your setup() method: |
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| Serial.begin(9600); |
| 9600 is the baud rate, something we will not get into here (it essentially means the number of signal changes made |
| per second, and merely ensures that the PC and the Arduino are on the same page in regards to this). Whenever you |
| would like to write something to the serial port, simply use the Serial.print or Serial.println function, as so: |
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| Serial.print(“Hello world!”); |
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| Reading from the Serial Port |
| Note that you will have to read in a single character at a time via the serial port, which is rather unfortunate. If you take |
| a peek at the sample code for our calculator application, specifically the waitForNum() method, you will see an exam- |
| ple of how to read in all characters entered, albeit in this case for a number. |
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| 8.2 Building a Calculator |
| To tie all of your new found programming knowledge together, we submit to you the following program that performs |
| basic mathematical operations. We have clearly commented the code, so you should be able to understand each step. |
| There is a download available for people who don’t like typing at: http://www.bradkendall.ca/arduino |
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| Here we go! |
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| /* |
| Example Arduino Calculator |
| Communication protocol: Send an ‘A’, ‘S’, ‘M’, or ‘D’ via serial, than two numbers. The arduino |
| will reply with the result of the operation on the two numbers, (first number first). Note that |
| the division will no doubt look strange - it is an integer division and therefore there will |
| not be anything after the decimal point. |
| */ |
| void setup() { |
| Serial.begin(9600); |
| Serial.println(“Calculator initiated.”); |
| } |
| /* loop() |
| This code gets executed over, and over, and over, and over, and over, and over, and over, and |
| over, and over, and over, and over, and over, and over, and over, and over, and over again. |
| Our loop pretty much starts the ‘waiting for input’ stage, where we wait for the user to input |
| a character (the mathematical operation), then two operands. |
| After we output the result, we let the loop get hit again, and joy is had by all! |
| */ |
| void loop() { |
| char operation; |
| int number1; |
| int number2; // hehe, Number 2. |
| int result; // Hold the result of the operation. |
| boolean success; |
| // Indicates whether the operation |
| // was successful (we knew what to |
| // do - nothing bad was inputted) |
| success = true; |
| // Go ahead and set success to true ; |
| // The only time we will be updating |
| // this variable now is to set it to |
| // false if we’ve encountered a |
| // problem. |
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| Serial.println(“Pick an operation: ‘A’dd, ‘S’ubtract, ‘M’ultiply, or ‘D’ivide (Simply input the |
| first letter in quotes.)”); |
| // We have to wait for the user to send something |
| // here; the easiest way to do so is to simply loop |
| // and waitfor Serial.available() to be true. |
| while(Serial.available() == 0) { |
| ; // ; indicates an empty statement. Or a sea |
| // monster in Nethack. God those suck. |
| } |
| // This loop will continue executing while Serial. |
| // available() == 0. Thus, it will be stuck here until |
| // the serial has a character waiting. |
| operation = Serial.read(); |
| // We have to do the same thing to get the two |
| // operands (numbers). |
| // I have factored this code into a function so that |
| // I do not have to rewrite it twice. See if you can |
| // determine why I would not be able to use it (at |
| // least intuitively) to get the operation. |
| Serial.println(“Okay, now please enter the two numbers, one at a time!”); |
| number1 = waitForNum(); |
| Serial.print(“Read: “); |
| Serial.println(number1); |
| number2 = waitForNum(); |
| Serial.print(“Read: “); |
| Serial.println(number2); |
| // Now we have read in all the data we need. It is |
| // time to calculate the result. We will have to |
| // determine what operation the user specified, and |
| // perform the calculation from there. |
| Serial.print(“Operation: “); |
| if(operation == ‘A’) |
| { |
| // This checks to see if the user sent along the |
| // character ‘A’, specifying an add. |
| Serial.println(“ADD (Look, a kitty!)”); |
| result = number1 + number2; |
| } else if(operation == ‘S’) |
| { |
| // Note that the above condition will only be |
| // tested for if operation is not equal to ‘A’ - |
| // hence the else. |
| // This code executes if the operation is ‘S’ for |
| // subtract. |
| Serial.println(“Subtract”); |
| result = number1 - number2; |
| } else if(operation == ‘M’) |
| { |
| // In this case, we will be multiplying. |
| Serial.println(“Multiply”); |
| result = number1 * number2; |
| } else if(operation == ‘D’) |
| { |
| // Here we will be dividing. |
| Serial.println(“Divide”); |
| result = number1 / number2; |
| } else{ |
| // This code will be used if the character |
| // specified doesn’t match anything - in other |
| // words, the user did not send A, S, D, or M, |
| // and we don’t know what to do. |
| // Hence, set ‘success’ to false |
| success = false; |
|
|
| } |
| // Now we should have our result. Time to send the |
| // user back something! (Then start over again! Joy!) |
| if(success) |
| { |
| // Note that print will not start a new |
| // line, and the next print statement will |
| // continue writing right |
| // where the previous one left off. |
| // Output the result. |
| Serial.print(“Result: “); |
| Serial.println(result); |
| } else |
| { |
| Serial.print(“Sorry, I don’t understand what you want me to do! (You inputted ‘”); |
| Serial.print(operation); |
| Serial.println(“’)”); |
| } |
| } |
| int waitForNum() |
| { |
| int ret; |
| while(Serial.available() == 0) { ; |
| } |
| // Why minus ‘0’? The value we’ll get from Serial. |
| // read() will be a character. What this means is |
| // that its numeric value will not necessarily |
| // reflect the number it represents. (Look at an |
| // ASCII table, the character ‘0’ actually has a |
| // decimal value of 48!) |
| // The take-away from this is that, since fortunately |
| // all the numbers are in sequence, you can simply |
| // subtract the decimal value of ‘0’ from |
| // whatever you read in, and you’ll be left with the |
| // number itself. ‘5’ - ‘0’ = 5 . |
| ret = Serial.read() - ‘0’; |
| // To handle numbers that span more than one |
| // character (like 124, which spans three), we must |
| // loop until there is no more input, and multiply |
| // each number we read by one (as 124 would come in |
| // like: 4 2 1 |
| // And the number we build would be: |
| // (((1 * 10) + 2) * 10) + 4, |
| // or 124! The joys of the decimal numbering system! |
| // Note that the delays are merely to slow things |
| // down a bit - removing them would have the |
| // code execute too quickly to ‘notice’ more |
| // characters waiting to come in from Serial. |
| // A little strange, neh? Welcome to the joys of this |
| // type of thing. =] |
| delay(10); |
| while(Serial.available() != 0) |
| { |
| ret = ret * 10; |
| ret += Serial.read() - ‘0’; |
| delay(10); |
| } |
| return ret; |
| } |
|
|
| |
| 8.3 Turning on an LED |
|
|
| What You Need: |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| 1 – LED |
|
|
| 1 – Resistor – 1 KOhm (brown, black, red) |
|
|
| 4 – Jumper Wires |
|
|
| You will build a circuit by plugging the LED and resistor leads into small holes called sockets on the breadboard. |
|
|
| Let’s get started! |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Plug a jumper wire from the 5V port on your Arduino into the positive section of your |
|
|
| breadboard’s power lane. |
|
|
| • Step 3 - Plug a jumper wire from the GND port on your Arduino into the negative section of your |
|
|
| breadboard’s ground lane. |
|
|
| • Step 4 - Plug the LED’s cathode (the short lead) into the I-2 socket on your breadboard. |
|
|
| • Step 5 - Plug the LED’s anode (the long lead) into the I-4 socket on your breadboard. |
|
|
| • Step 6 - Plug one of the resistor’s leads into the H-4 socket on your breadboard. |
|
|
| • Step 7 - Plug the resistors other lead into the H-9 socket on your breadboard. |
|
|
| • Step 8 - Connect a jumper wire from your breadboard’s power lane to the J-9 socket on your |
|
|
| breadboard. |
|
|
| • Step 9 - Connect a jumper wire from your breadboard’s ground lane to the J-2 socket on your |
|
|
| breadboard. |
|
|
| • Step 10 - Reconnect the USB cable to your Arduino. |
|
|
| Summary: Once power is applied to the circuit, the LED will turn on. This is about as simple as a circuit gets. |
|
|
| 8.4 Making Your LED Blink |
| What You Need: |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| 1 – LED |
|
|
| 1 – Resistor – 1 K Ohm (brown, black, red) |
|
|
| 4 – Jumper Wires |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Plug a jumper wire from the Digital IO pin 8 into the I-12 socket on your breadboard. |
|
|
| • Step 3 - Plug one of the resistor’s leads into the H-12 socket on your breadboard. |
|
|
| • Step 4 - Plug the resistor’s other lead into the H-4 socket on your breadboard. |
|
|
| • Step 5 - Plug the LED’s cathode (the short lead) into the I-2 socket on your breadboard. |
|
|
| • Step 6 - Plug the LED’s anode (the long lead) into the I-4 socket on your breadboard. |
|
|
| • Step 7 - Connect a jumper wire from your breadboard’s ground lane to the J-2 socket on your |
|
|
| breadboard. Ensure that the ground lane is still grounded. |
|
|
| • Step 8 - Reconnect the USB cable to your Arduino. |
|
|
| Software Setup: |
|
|
| Open up your Arduino Development Environment and create a new sketch (File > New). |
|
|
| Enter the following code into your sketch: |
|
|
| void setup() { |
| // initialize the digital pin as an output. |
| // Pin 8 is our output pin |
| pinMode(8, OUTPUT); |
| } |
| void loop() { |
| digitalWrite(8, HIGH); // set the LED on |
| delay(1000); // wait for a second |
| digitalWrite(8, LOW); // set the LED off |
| delay(1000); // wait for a second |
| } |
|
|
| After you enter the code, press the upload button and your LED should start blinking. |
|
|
| Summary: The digitalWrite(8, HIGH); command sets the output pin 8 on the Arduino to 5V. The digitalWrite(8, LOW); |
| command sets the output pin 8 on the Arduino to 0V. The delay(1000); command pauses execution on the Arduino for |
| 1000 ms or 1 second. Since this in the loop() function, the code is called over and over again. Pretty cool, huh? |
|
|
| 8.5 Making Multiple LEDs Blink |
|
|
| What You Need: |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| 2 – LEDs |
|
|
| 2 – Resistor – 1 K Ohm (brown, black, red) |
|
|
| 4 – Jumper Wires |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Setup the project board the same as in Project 3. |
|
|
| • Step 3 - Plug a jumper wire from the Digital IO pin 9 into the I-16 socket on your breadboard. |
|
|
| • Step 4 - Plug one of the resistor’s leads into the H-16 socket on your breadboard. |
|
|
| • Step 5 - Plug the resistor’s other lead into the H-24 socket on your breadboard. |
|
|
| • Step 6 - Plug the LED’s anode (the long lead) into the I-24 socket on your breadboard. |
|
|
| • Step 7 - Plug the LED’s cathode (the short lead) into the I-26 socket on your breadboard. |
|
|
| • Step 8 - Connect a jumper wire from your breadboard’s ground lane to the J-26 socket on your |
|
|
| breadboard. Ensure that the ground lane is still grounded. |
|
|
| • Step 9 - Reconnect the USB cable to your Arduino. |
|
|
| Software Setup: |
|
|
| Open up your Arduino Development Environment and create a new sketch (File > New). |
|
|
| Enter the following code into your sketch: |
|
|
| void setup() { |
| // initialize the digital pins as an output. |
| pinMode(8, OUTPUT); |
| pinMode(9, OUTPUT); |
| } |
| void loop() { |
| digitalWrite(8, HIGH); // set the LED on |
| digitalWrite(9, LOW); // set the LED on |
|
|
| delay(1000); // wait for a second |
| digitalWrite(8, LOW); // set the LED off |
| digitalWrite(9, HIGH); // set the LED on |
| delay(1000); // wait for a second |
| } |
| After you enter the code, press the upload button and both your LEDs should start blinking. |
|
|
| Summary: This project is exactly the same as the last project, except we have added an additional LED on output pin |
| 9 that turns off when the other LED is on. Can you think of any other ways to expand on this? |
|
|
| 8.6 Pushbuttons with a Pull-up Resistor |
| What You Need: |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| 1 – Resistor 2 K Ohm (red-black-red) |
|
|
| 1 – Resistor – 1 K Ohm (brown, black, red) |
|
|
| 1 – Tactile Switch |
|
|
| 5 – Jumper Wires |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Connect a jumper wire from your breadboard’s power lane to the C-3 socket on your |
|
|
| breadboard. Ensure that the power lane is still connected. |
|
|
| • Step 3 - Plug one of the 2 K Ω resistor’s leads into the B-3 socket on your breadboard. |
|
|
| • Step 4 - Plug the 2 K Ω resistor’s other lead into the B-7 socket on your breadboard. |
|
|
| • Step 5 - Plug a tactile switch so the pins are in the F-9, F-7, E-9 and E-7 on your breadboard. |
|
|
| • Step 6 - Plug one of the 1K Ω resistor’s leads into the H-7 socket on your breadboard. |
|
|
| • Step 7 - Plug the 1K Ω resistors’ other lead into the H-14 socket on your breadboard. |
|
|
| • Step 8 - Plug a jumper wire from the Digital IO pin 9 into the I-14 socket on your breadboard. |
|
|
| • Step 9 - Connect a jumper wire from your breadboard’s ground lane to the H-9 socket on your |
|
|
| breadboard. Ensure that the ground lane is still connected. |
|
|
| • Step 10 - Reconnect the USB cable to your Arduino. |
|
|
| Software Setup: |
|
|
| Open up your Arduino Development Environment and create a new sketch (File > New). |
|
|
| Enter the following code into your sketch: |
|
|
| void setup() { |
| // initialize the digital pin 9 as an input. |
| pinMode(9, INPUT); |
| // initialize the serial port. |
| Serial.begin(9600); |
| } |
| void loop() { |
| int buttonStatus = digitalRead(9); |
| if (buttonStatus == LOW) //The button is down |
| { |
| Serial.println(“The button is down”); |
| } |
| } |
|
|
| After you enter the code, press the upload button and open the Serial Monitor (Tools > Serial Monitor). When you |
| press the tactile switch, the serial monitor should print “The button is down”. |
|
|
| Summary: This project reads the digital input for 5v (HIGH). When the button is pressed, the voltage is set to 0v |
| (LOW) and the Arduino executes the code in our if statement. |
|
|
| 8.7 Turning on an LED with a Pushbutton |
|
|
| What You Need: |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| 1 - LED |
|
|
| 1 – Resistor – 1 K Ohm (brown, black, red) |
|
|
| 1 – Tactile Switch |
|
|
| 4 – Jumper Wires |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Plug a tactile switch so the pins are in H-9, H-11, J-9 and J-11 on your breadboard. |
|
|
| • Step 3 - Plug a jumper wire from the GND port on your Arduino into the negative section on your |
|
|
| breadboard’s ground lane. |
|
|
| • Step 4 - Plug the LED’s cathode (the short lead) into the I-2 socket on your breadboard. |
|
|
| • Step 5 - Plug the LED’s anode (the long lead) into the I-4 socket on your breadboard. |
|
|
| • Step 6 - Plug one of the resistor’s leads into the H-4 socket on your breadboard. |
|
|
| • Step 7 - Plug the resistor’s other lead into the H-9 socket on your breadboard. |
|
|
| • Step 8 - Connect a jumper wire from your breadboard’s power lane to the G-11 socket on your |
|
|
| breadboard. |
|
|
| • Step 9 - Connect a jumper wire from your breadboard’s ground lane to the J-2 socket on your |
|
|
| breadboard. |
|
|
| • Step 10 - Reconnect the USB cable to your Arduino. |
|
|
| 8.8 Control an LED’s Brightness |
| What You Need: |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| • |
|
|
| 1 – Photo Resistor |
|
|
| 1 – Resistor – 2 K Ohm (red-black-red) |
|
|
| 1 – LED |
|
|
| 5 – Jumper Wires |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Plug one of the photo resistor’s leads into the I-14 socket on your breadboard. |
|
|
| • Step 3 - Plug the photo resistor’s other lead into the I-15 socket on your breadboard. |
|
|
| • Step 4 - Plug the LED’s cathode (the short lead) into the H-17 socket on your breadboard. |
|
|
| • Step 5 - Plug the LED’s anode (the long lead) into the H-15 socket on your breadboard. |
|
|
| • Step 6 - Plug one of the resistor’s lead into the I-17 socket on your breadboard. |
|
|
| • Step 7 - Plug the resistor’s other lead into the I-22 socket on your breadboard. |
|
|
| • Step 8 - Connect a jumper wire from your breadboard’s power lane to the J-14 socket on your |
|
|
| breadboard. Ensure that the power lane is still connected. |
|
|
| • Step 9 - Connect a jumper wire from your breadboard’s ground lane to the J-22 socket on your |
|
|
| breadboard. Ensure that the ground lane is still connected. |
|
|
| • Step 10 - Reconnect the USB cable to your Arduino. |
|
|
| Summary: As you see, the resistance of the photo resistor decreases with more light. The lower the resistance, the |
| brighter the LED. Combine this with the pull up resistor project (Chapter 8.6) and watch the opposite effect. |
|
|
| 8.9 Observing Light with your Arduino |
| What You Need: |
|
|
| • |
|
|
| 1 – Photo Resistor |
|
|
| • |
|
|
| • |
|
|
| 1 – Resistor – 10 K Ohm (brown-black-orange) |
|
|
| 5 – Jumper Wires |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Plug one of the photo resistor’s leads into the F-16 socket on your breadboard. |
|
|
| • Step 3 - Plug the photo resistor’s other lead into the F-15 socket on your breadboard. |
|
|
| • Step 4 - Plug one of the resistor’s leads into the I-15 socket on your breadboard. |
|
|
| • Step 5 - Plug the resistor’s other lead into the I-10 socket on your breadboard. |
|
|
| • Step 6 - Connect a jumper wire from your breadboard’s power lane to the G-16 socket on your |
|
|
| breadboard. Ensure that the power lane is still connected. |
|
|
| • Step 7 - Connect a jumper wire from your breadboard’s ground lane to the J-10 socket on your |
|
|
| breadboard. Ensure that the ground lane is still connected. |
|
|
| • Step 8 - Plug a jumper wire from the Analog IO pin 0 into the G-15 socket on your breadboard |
|
|
| • Step 9 - Reconnect the USB cable to your Arduino. |
|
|
| Software Setup: |
|
|
| Open up your Arduino Development Environment and create a new sketch (File > New). |
|
|
| Enter the following code into your sketch: |
|
|
| int lightPin = 0; //define a pin for Photo resistor |
| void setup() |
| { |
| Serial.begin(9600); //Begin serial communication |
| } |
| void loop() |
| { |
| //Write the value of the photo resistor to the serial //monitor. |
| int lightValue = analogRead(lightPin); |
| Serial.println(lightValue); |
| delay(1000); //pause for 1000 ms or 1 second. |
| } |
|
|
| After you enter the code, press the upload button and open the Serial Monitor (Tools > Serial Monitor). The console |
| should give a light reading in the form of an integer. When you reduce the amount of light, the number will be lower. |
|
|
| Summary: This project is the same as the previous project, except we are reading the values from your Arduino |
| instead of outputting to an LED. The resistance of the photo resistor decreases with more light. You could use logic to |
| reverse this effect! |
|
|
| 8.10 Making Music with your Arduino |
| What You Need: |
|
|
| • |
|
|
| • |
|
|
| 1 – Piezo Speaker |
|
|
| 3 – Jumper Wires |
|
|
| Hardware Setup: |
|
|
| • Step 1 - Unplug the USB cord from your Arduino. |
|
|
| • Step 2 - Plug the positive lead of your piezo speaker into the E-15 socket on your breadboard. |
|
|
| • Step 3 - Plug the negative lead of your piezo speaker into the F-15 socket on your breadboard. |
|
|
| • Step 4 - Plug a jumper wire from the Digital IO pin 8 into the A-15 socket on your breadboard. |
|
|
| • Step 5 - Connect a jumper wire from your breadboard’s ground lane to the J-15 socket on your |
|
|
| breadboard. Ensure that the ground lane is still connected. |
|
|
| • Step 6 - Reconnect the USB cable to your Arduino. |
|
|
| Easy, right? |
|
|
| Software Setup: |
|
|
| This project is included in the Examples Section. No typing on this one! Open up your Arduino Development Environ- |
| ment .Open the toneMelody Example Sketch (File > Examples > Digital > toneMelody). |
|
|
| After you enter the code, press the upload button and your piezo speaker will start making noise. You can modify the |
| sound by modifying the melody[] and noteDurations[] arrays. |
|
|
| Summary: This project produces sound out of the piezo speaker. |
|
|
| 9. Where to go From Here |
|
|
| As you can see, the Arduino is an easy way to get into electronics and software. Hopefully you have seen that it is |
| easy to build simple electronic projects with it. I hope you have realized that your projects don’t have to stay simple. |
| You can build way more complex projects on top of these simple ones. Here are some of my favorite projects that |
| would be a great next step: |
|
|
| • Create Christmas light ornaments |
|
|
| • Arduino Traffic light controller |
|
|
| • Arduino Shields to superpower your project |
|
|
| • Make your own Arduino |
|
|
| • Build your own pong game with an Arduino |
|
|
| • Connect your Arduino to the internet |
|
|
| • Create a home automation system with your Arduino |
|
|
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