Q: The GertDuino is an accessory. That’s a bit of a vague term. Can you be a little more specific?
A: The GertDuino is basically another circuit board that you can attach to the Raspberry Pi, extending its functionality beyond the original chips and ports and such.
Q: A circuit board connected to another circuit board. I see. What’s with the name, though? Sounds familiar.
A: Well it’s named after two things. Firstly, Gert is the name of the guy who invented it – Gert van Loo. He’s a hardware engineer who’s been working on the Raspberry Pi since the alpha boards, and currently still volunteers at the Foundation. He’s an active mod on the forums, and worked on the Raspberry Pi camera board as well.
Q: Oh yeah, didn’t he release another circuit board with his name on?
A: That’s correct: Gert also invented the Gertboard, another Raspberry Pi accessory.
Q: So how is that different from the GertDuino? Is the GertDuino a Gertboard upgrade?
A: Not exactly. The Gertboard extends the functionality of the GPIO ports on the Raspberry Pi, allowing you to power motors, detect switches, illuminate LEDs and generally allow it to interact with the physical world. The GertDuino does a bit more than that.
Q: So the Gert part I now get, what’s with Duino?
A: Duino as in Arduino, the open source microcontroller platform. GertDuino incorporates an Arduino microcontroller into its design.
Q: That sort of answers my question, but what exactly is a microcontroller?
A: A microcontroller is a bit like a CPU; however it has specific inputs and outputs that are specifically programmable for the task at hand. It’s a lot more cost- and space-efficient than an entire computer system built up to do it, as it manages to do all the operations on a single chip. The type of microcontroller used in the GertDuino has a lot of physical circuits, allowing people to not need to build the physical board up around the microcontroller.
Q: That sounds pretty neat. What’s the deal with it being Arduino then?
A: Well, as we said, it’s open source. Open hardware. The specs are there for everyone to use, so it’s easily implemented into the GertDuino with no licensing fee. Arduino is also extremely popular as microcontrollers go, making it easier for people to pick it up if they’ve got experience with it
Q: Experience with it? Is there anything particularly special about their operation?
A: Arduinos can be controlled with the Arduino IDE, a cross-platform language that is designed to be slightly easier to use for people who don’t have any formal training in coding. Even if you do write code in C, either way it allows you to upload programs, or a sketch, to the Arduino board itself.
Q: Okay then, that also sounds pretty good. So the GertDuino adds an Arduino chip to the Raspberry Pi. Isn’t the Raspberry Pi already programmable and small anyway?
A: It’s not quite that simple – yes, the Raspberry Pi is a full computer on a chip. However, it lacks the necessary functions and I/O ports to be used the same way as an Arduino chip/board. It’s sort of like trying to print because you have all the software, but you still don’t have an actual printer.
Q: I’ll take your word for it. How does the GertDuino connect to the Raspberry Pi?
A: Like the Gertboard and most other major add-ons, it’s connected via the GPIO ports. These are the major expansion ports for the Raspberry Pi, and it allows the Pi to properly speak with the Arduino chip. This allows you to actually then program the Pi, which will then program the Arduino to do the work you want it to do.
Q: Can you not connect a normal Arduino up to a Raspberry Pi then?
A: Actually, you can. People have been using the Raspberry Pi to help power Arduino boards since it first came out.
Q: So what’s the upside of using a GertDuino over a standard Arduino board?
A: Well for one, it’s actually pretty cheap compared to an equivalent Arduino board, although it’s tied a bit to the Raspberry Pi as a result. Secondly, it offers the same functionality as one of the major Arduino boards, the Arduino Uno. It’s also completely compatible with everything that works with the Uno, and offers a few more features on top of all that.
Q: A few more features? What would those be then?
A: Well, it has a special chip on it called an ATmega 48, which offers infrared signal support, a very precise real-time clock as well as a some form of spare battery. The main chip is called the ATmega 328, by the way. It can also be unplugged from the Raspberry Pi once you’re done programming it, and it will work on its own thanks to the ATmega 48’s battery.
Q: So it sounds pretty nifty, but what can I use it to do?
A: Arduino powers a large number of physical hobby projects. Garage door openers, robots, home breweries and even some of the Makerbots. The GertDuino is capable of all of the functions that similar Arduinos can perform. Gert van Loo himself has suggested that you can use it to time the opening of a chicken coop in the morning, or as a remote for opening and closing curtains.
Q: Just for hobby projects? What A about full commercial projects?
A: While Arduino boards are fantastic for rapid-prototyping and tinkering with low financial risk, when your product is complete it is usually a lot cheaper to start making custom chips. For everyone else, though, it’s the most cost-effective for both prototypes and final products.
Q: All right then, I think it’s time to get one. My Rube Goldberg alarm clock needs upgrading. Where do I get one of boards?
A: You can buy a board from element14, which coincidentally is one of the two major distributors of Raspberry Pis. The manual for the board is also available there, along with some basic guides on how to use it, and more useful information on the board itself.