Electricity is created by the movement of electrons. Energy is produced, which can be harnessed to create a charge. Charges power light bulbs, air conditioners, video gaming systems, electric cars, and many other things.
HOW IT WORKS
To understand electronics, one must understand its building blocks: voltage (volts or V), currents (amperes or A), and resistance (omega or ohm). Working with electricity means working with two points. One of these points always has a greater charge than the other. That difference is called voltage. The rate at which the charge flows is known as current. Resistance is the material’s tendency to resist the electrical current. When discussing these values, we’re really talking about the movement of charge and ultimately the behavior of electrons.
When working with electronics, makers build electric circuits. These pathways are made of wire through which electrons flow. A power source provides voltage, causing the electrons to move, and thus power up a device. For example, a simple circuit can cause a light to blink or a gadget to play your favorite tune.
This action is controlled by a microcontroller. These tiny, but powerful, computers are on a single integrated circuit, also known as a computer chip. They are commonly used in everything from keyboards Page 34 | Top of Articleand modems to printers and vehicles. You can code microcontrollers to perform actions, such as measuring, calculating, and displaying information. There are two ways to use a microcontroller. Use a microcontroller motherboard or integrate a microcontroller on a circuit board (temporarily or permanently with soldering). The former is the easiest for beginners, and the most popular microcontroller motherboard is Arduino (pronounced ar-DWEE-no).
LEARNING WITH ARDUINO
Arduino is an open-source microcontroller board—a simple computer—that runs a simple program over and over again. Makers write code in Arduino’s software, which tells the microcontroller what to do. Arduino is powered by batteries (regular or solar) or electricity from an electrical wall socket. Arduino is easy to build and modify, allowing you to make all sorts of interactive toys, tools, gadgets, and robots. You can even program Arduino to send a Tweet when your morning coffee is ready.
To make a basic Arduino, you’ll need an oscilloscope to monitor voltage and the continuity of an electrical circuit. You’ll also need a soldering iron to attach components and wires to a circuit board. Additional tools include wire cutters and wire strippers. Eventually you’ll learn how to design your own circuit boards. This will enable you to create more advanced projects, such as robots and mobile devices. More complex electronics include robotics, which calls for more advanced tools and problem-solving skills.
Arduino Uno is the most common type of microcontroller motherboard. Mega’s slightly larger circuit board follows Arduino Uno in popularity. It comes with a 256 KB of memory, eight times more than that of Arduino Uno. Arduino Mega ADK is a specialized version of Arduino Mega. It interfaces with Android devices. Arduino LilyPad uses conductive thread and is specifically designed for textile projects.
ADVANCING TO RASPBERRY PI
If you plan to build a more complicated project or one that performs more than a single task, you’ll need Raspberry Pi. Raspberry Pi is a general-purpose computer that uses a Linux operating system. It’s a bit more complicated than Arduino, but just as fun, and even more functional. Examples of Raspberry Pi projects include an automated cat feeder and Page 37 | Top of Articlea tea kettle activator that measures water temperatures before lowering the tea into the kettle for brewing.
When determining whether to use Arduino or Raspberry Pi for your project idea, consider the rule of thumb offered by Patrick Di Justo of Makezine.com . He wrote, “Think about what you want your project to do. If you can describe it with less than two ‘and’s, get an Arduino. If you need more than two ‘and’s, get a Raspberry Pi.” Di Justo continues by offering this example:
“I want to monitor my plants and have them Tweet me when they need water.” That can best be done by an Arduino. “I want to monitor my plants and have them Tweet me when they need water and check the National Weather Service and, if the forecast is for fair weather, turn on the irrigation system and if the forecast is for rain, do nothing.” That would best be handled by a Raspberry Pi.
Electronics at this level are low powered and are considered safe. In general, care should be taken when working with any materials (batteries, circuit boards, and sensors) and tools (wire strippers, stands, and vacuums). Working with electronics often requires soldering. In general, solder contains lead. Although it does not present a health risk, it’s always a good idea to wash your hands after working with the Page 38 | Top of Articlematerial for a long period of time. You can also use a lead-free solder, but it is difficult to work with. Lead-free solder requires higher soldering temperatures. It also produces toxic fumes and corrodes soldering tips. Regardless of your choice, be sure to work in a well-ventilated area. Use caution when working with soldering irons as they can reach approximately 400°F (204°C).
PROJECT 6: STAR CHARTS POWERED BY ARDUINO
Star charts, or star maps, are used to navigate the sky. They feature the brightest stars (spheres of hot gas) and constellations (groups of stars) as seen from the Earth. And now you can make your own star chart. The project calls for WS2812B LEDs and Arduino Uno, which controls each LED individually in order to showcase a particular constellation.
Additional items include a 5V power supply, press board, flat black spray paint, aluminum foil, a silver-colored Sharpie marker, and an adhesive (hot glue, packing tape, or duct tape). A drill with at least three bits of various sizes will be needed to punch holes in the press board. These will be used for the stars. A router can be used to create a border around the stars. After applying a coat of flat black spray paint, you can put the LEDs in place and let the constellations wow your teachers and classmates!
PROJECT 7: DIY ROBOTS
Robots have long fascinated people. Books have been written about them, movies tell of their exploits, and now makers create them to impress teachers, classmates, and science fair attendees. Robots come in all shapes and sizes and are used in many industries, including education, entertainment, manufacturing, and science. They are categorized as ground robots with fixed arms, humanoids, rovers, turtles, and walkers. They can also be aerial vehicles or underwater robots. Robots can function automatically or be controlled by computer.
Students who are interested in robotics are encouraged to begin with circuit-based analog robots. Electronic circuitry causes them to move and be controlled using a wired remote controller. Page 41 | Top of ArticleThe first turtle robots, Elmer and Elsie, and underwater remotely operated vehicles (ROVs) are analog robots. But don’t be intimidated by these projects. Kits are available with the circuit design already in place. You can also build your own. This project helps you create an obstacle-avoiding, wall-follower robot that is controlled by a smartphone. Among the materials needed are Arduino Uno, a gear motor, wheels, 9V batteries, and a plastic box. You’ll also need a soldering iron, hot glue gun, screwdriver, and drill.