By Kalani Kirk Hausman,
The Arduino is a small Atmel-based microcontroller development board easily integrated into many different types of digital control and automation. Hundreds of thousands of Makers, hobbyists and researchers around the world make use of Arduino variations every day for wearable electronic displays, automatic gardening controls, robotic designs and numerous other uses from home decorations to the control for many types of 3D printers. The Arduino is inexpensive (around $25 US for commercially produced boards), but can be built for under $6 US from basic components because its entire design is open source and readily integrated into many other alternatives, which often carry the “’duino” designation to illustrate their origin. Arduino is also expandable with hundreds of different add-on boards, called Shields, available for environmental monitoring, robotic control, network access and even cellular phone capabilities.
The current Arduino, called Leonardo, uses a 16Mhz Atmel microcontroller with 32KB Flash memory, 12 bidirectional Analog pins, 20 bidirectional Digital pins, 7 PWM outputs and 2 TWI/I2C interfaces for those who tinker with electronics. The newer Arduino Due expands this using a 32-bit ARM microcontroller capable of running a more complex code set, although this is the first Arduino that is compatible with most Shields but not with the Processing language (C variant programmed using the free Arduino IDE) files and libraries used but the more traditional Arduino Leonardo and earlier Arduino Due boards. Arduino includes many different format boards suitable to different purposes from small single chip designs with all components soldered directly onto the Atmel microprocessor to sew-in washable Arduino alternatives. The variety of options means there will always be an Arduino that will fit your project, or as an open-source technology, you can always add a new option and perhaps sell it to suit the needs of others as well! Because Arduinos draw very little power, they are perfect for on-the-go battery-based or solar-powered electronic controls, although they can easily be powered from standard USB connections and wall-wart power supplies.
Adding network capability to an Arduino requires an additional Shield, but for simple web servers and web-accessible controls, the magnificent Raspberry Pi (around $35 US) created for UK educational use is a magnificent little computer the size of a credit card. Like the Arduino, Raspberry Pi boards have add-on options, called Plates, that support additional sensors and control circuits, but the RasPi includes an on-board Ethernet connection, two USB ports and an SD card slot for storage. Unlike the Arduino, Raspberry Pi is a true computer, able to run a stripped down version of the Linux operating system. It was meant for children to be able to learn computer programming and Internet capabilities in educational settings but has rapidly become a favorite platform for building hand-held laptop computers for under $100 US, mining Bitcoins, running a MAME video game server, or operating as a home theater PC using its built-in HDMI output.
The Raspberry Pi has almost as many Makers and hobbyists building new solutions as the Arduino, although its built in connections are less capable of directly interfacing with other electronics, often resulting in Arduino/RasPi combinations for complex projects. Raspberry Pi includes a 700MHz ARM microprocessor, 256MB on-board memory, 8 GPIO (general-purpose input/output) Digital pins, HDMI and Composite video and stereo audio output, 2 USB connections and a built-in Ethernet connection. It uses SD memory cards and can run several compatible Linux variations. This is a simple, easy-to-use computer on a single card perfect for learning computer programming and setting up web-enabled services with a fantastic community of supporters.
Unlike the Arduino, the Raspberry Pi is not an open-source hardware platform, it was created for the British government for use in school settings and remains proprietary technology. Many who prefer entirely open-source designs or who want the power of a credit-card sized single-board Linux computer with the flexibility of the Arduino’s electronics will look to the BeagleBone Black ($45 US). This platform is often used in more complex robotic designs like underwater ROVs, and includes a 1GHz ARM microprocessor, 2.5GB onboard memory, 7 Analog and 65 GPIO Digital pins, with 8 PWM outputs and 2 TWI/I2C interfaces like the Arduino. BeagleBone Black uses microSD cards for storage, provides HDMI video and stereo audio output, and includes a built-in Ethernet port and a single USB connection for external hardware connection. With its more powerful CPU, the BeagleBone Black can operate with Android and common Linux operating systems like the popular Ubuntu distribution. It also has many add-on boards, called Capes, although its support base is limited by comparison with the massive communities behind Arduino and the Raspberry Pi.
If you want to enable your designs with sensor-based controls like an automatic Halloween scare-prank to greet little monsters or web-enabled capabilities like tweeting when the bird bath has a visitor, these solutions are magnificent as inexpensive and flexible options for any level of experience with electronics. Parents, kids, educators and Makers alike can all find nearly infinite applications for the single-board, credit-card-sized electronic boards with many add-ons (Shields, Plates or Capes, depending on which board you select). They work together with each other and as expansions to other commercial products or standalone platforms for your own creativity.
For a basic go-to board for battery-based designs, one of the many open-source Arduino variations will be hard to beat, while Raspberry Pi provides a single-board computer for learning computer programming, setting up a web server, or playing your video collection on the living room TV without a noisy full computer. If your need exceeds the ability of each of these alone, the BeagleBone Black integrates the full power of Android and Linux in an open-source platform with numerous electronic connections to build your own Geiger counter, secret lapel camera, autonomous drone, or ROV for spying on your arch rival’s secret underwater lair!
Kalani Kirk Hausman is a long-time IT professional who is currently conducting research at Texas A&M University on integrating 3D printed materials into educational curricula. Kirk has worked in a variety of higher education, medical, health care, government, and commercial enterprise settings and is the author of the upcoming 3D Printing For Dummies from Wiley.