To be very honest, the lines are starting to get harder to detect between Arduino and Raspberry Pi.
The Raspberry Pi was designed mainly to be a tool to help and teach students — and regular people, I suppose, in general — programming, and I know that its creator, Eben, was noticing less people applying to go to college and had the idea to make it cheap and easy to do. The non-threatening issue now is that people are noticing what’s really on this Raspberry Pi besides your normal I/O ports; they (self included) have been developing with these GPIO headers to do more with the Pi.
To you and me, it looks like an EIDE cable should fit onto it, but in reality, hopping up some headers and using a breadboard, you can now turn your Pi into a microcomputer for which you can build your own hardware. From lighting LEDs to making your own home security system with a PIR motion detector using the Linux/ARM OS, you get to be a system builder (if you make a housing using a 3D printer), an OEM, a programmer (you have to learn code and get it to work), and a hardware engineer with the Pi; with Arduino or a similar microcontroller, you’d normally just plug in and be done.
The Arduino was also made to help teach — in this case, electronics. It is known to use ATTinyxx/ATMega microchips, and it’s on a board with a simple USB cord that can offer power and transfer Arduino “sketches” to the microchip without the need for its user to be a microchip programmer. It also has an option/input for alternate/wall power using only 5V (for instance, a phone charger will work; in fact, it’s what I use).
Like the Raspberry Pi, it has headers, but on most of the Arduinos, we have female headers (meaning we can just plug wires in), which is basically all it has. It does not have an OS, but the microchip has a bootloader and the capabilities to read C#/Arduino code (aka sketch projects) and understand that you want to listen on pin x, and if pin x’s value is xx, go do blah blah.
The Arduino being a microcontroller is great for hardware hacking, but it is not meant at all to be like a computer. You could make an LCD character screen to work with the Arduino and have it output values like temperature, colors detected, and fans running onto a marquee when people walk by, for instance.
Another great thing is the MaKey MaKey (billed as “an invention kit for everyone”), which allows you to use fruit, putty, or anything that conducts electricity into a controller that can connect right to your PC; you can even use it to make a discreet panic button out of not easily suspected materials if the boss comes in! This is, again, another use for the Arduino; people make these “shields” that can slide right on top of a project like a LEGO kit that can add different types of functionality — like a servo motor to control a dancing monkey, camera input, NIC card, SD card for data logging, etc.
I recently made a video (and offer the source code) for my recent Arduino project; I use an Arduino Uno with a Sparkfun Silver Bluetooth modem that gets controlled by my Nokia Lumia 920 using Windows Phone 8 (as 7.x is not capable). In the video, I control an LED and a robot motor with a wheel.
Why do I bring my project up? We can now control things — besides quadcopters — with our mobile devices. We can make robots or control our TVs, use closed captioning to ignore commercials, automate our homes, etc. with our phones using $1.87 IR LEDs! We can recycle our phones for other purposes when we upgrade to newer models.
The future of technology can become so cheap — cheap enough that we can put it into anyone’s hands (even middle school students), absent of the worry associated with the potential for expensive electronics to break. It can be used to teach the basics of electronics, basic software commands, and beyond; with a little soldering, people can learn new skills that will keep them educated and employed without the need for extensive academic degrees.
That is why I think the Arduino and Raspberry Pi are so popular and will continue to be. This simple, but potentially powerful technology endows ordinary people with the ability to tinker, learn, and apply ideas to practical applications within the boundaries of the most modest budgets. I imagine a day when we can create our own devices and learn from/teach each other. You don’t like that new product you bought? Okay. I will use my Arduino and make it better — and for $4, here’s how to do it!
It’s an exciting time to be alive.
Image: VESA Mount Installed by Solarbotics (via Flickr)