The Raspberry Pi

The Raspberry Pi model 3 is a small computer. At its core, it is similar to the computer inside a modern smart phone. It has a Quad Core 1.2 GHx Boradcam 64 bit CPU, 1GB of non-upgradable RAM, Ethernet, Wireless, Bluetooth, and HDMI output. It has a special connector for a camera, a special connector for a small touchscreen display, a micro SD port which serves as the operating system’s “hard drive” including storage of your data. You plug it into a 2.5 amp Micro USB cabled power brick.

The Raspberry Pi also has 4 USB 2 ports.

It costs $35. All you need to do is to add a power brick, an SD card, an HDMI monitor of some sort, maybe a case, a keyboard, a mouse, and perhaps a few other accessories, and pretty soon you nave a reasonably powerful $35 computer for a mere $200!

Or, you can leave off much of that stuff, hook it temporarily to a monitor, keyboard, and mouse (optional, I suppose) and set it up for SSH, then turn it back into a headless (and keyboardless, mouseless) server, communicating with it via wireless from your desktop or laptop.

Then, you take the thing and build stuff with it. Think of the Raspberry Pi, potentially, as a controller you might use for any device that requires controlling, but a very very smart one. Not yet mentioned is one of the key features of the Raspberry Pi: The GPIO header. This is the General Purpose Input Output array of 40 pins that are controlled by the computer, for both output and input, and power supply, to any of a very large range of sensors, actuators, and other devices.

I’ll stop right here and mention the Raspberry Pi Sense HAT. A “hat” or “shield” is a circuit board designed to stick right on top of another circuit board (in this case, the Rapsberry Pi) to give it a bunch of added functionality all at once. Often, a hat or shield has pass through pins for all or most of the GPIO pins, so you still have the same device you had before, but with a bunch of stuff added. The standard sense hat for this device has environmental sensors such as temperature, humidity, atmospheric pressure, and orientation. But I digress.

Anyway, a robot requires a “brain” that may or may not be hooked up via, say, Bluetooth, to a hand held remote of some sort, and also, to the motors that control the wheels (or anything else on the motor that moves), lights, sensors, all that. The most efficient way to build a robot probably uses a more basic controller than a Raspberry Pi, and indeed, most robots use a controller that is built with the specifications of an Arduino Uno, which costs typically less than $20 (and cheap Chinese knockoffs much cheaper, but they don’t all work quite like they are supposed to).

The difference between a dedicated basic controller and a fancier full on computer like a Raspberry Pi is like the difference between teaching your pet to do a trick and teaching your child to do a trick. The latter has way more overhead, but you can do fancier tricks and you can also teach the child to bring you a beer. On the other hand, the pet will just do the trick, while your kid will probably, eventually, give you lip and you’ll have to be nice to it or it will stop working right.

A Veritable Robot Army

Today, there is a veritable robot army out there, of robot kits you can build that are based on Raspberry Pi. I myself have built a version of SunFounder Smart Video Car and it is a great robot. The Adeept PiCar-A Wireless is very cool looking, and is a bit cheaper. Do not, however, that most, probably all, ready to build Raspberry Pi based robot kits do NOT come with the actual Raspberry Pi.

The Basic Robot

It might be helpful to know what the basic robot typically consists of.

Robots have two drive wheels, each powered by a separate tightly programmed specialized motor. There is a third wheel or some other roundy object to keep the robot balanced (usually) so the vehicle turns by moving the two drive wheels at different speeds. This works great on small robot scales. Robots typically have lights or sound making devices that are fun for the kids to program. Most robots have this sensor out front that looks like a set of eyes, but it is really a distance sensor, so you can program the robot to almost but not quite run into things, stopping at the last second. Many robots have a separate sensor facing down, out front, that allows the robot to follow lines or edges, if the lines or edges are just right and the programming is well done, and the sensor is set at just the right height (and thus, when they are installed, they should always be adjustable for height!).

And, of course, a basic robot has some kind of controlling device, such as a bit of software on a smart phone, a simple remote control, or, in the case of the robot you build with the book I’m about to tell you about, a Wii remote.

Learning Robotics with a Raspberry Pi

Learn Robotics with Raspberry Pi: Build and Code Your Own Moving, Sensing, Thinking Robots is written by The Raspberry Pi Guy, aka Matt Timmons-Brown. Matt is an old teenager (probably still, maybe he’s 20) and runs a Youtube Channel called “The Raspberry Pi Guy.”

In this book, the reader is given an introduction to the Raspberry Pi, and some basic electronics. Then, you start building the robot, adding more and more capabilities, until you have the basic robot described above, but then going to the next level so it will have the power of vision and a modest bit of artificial intelligence. The book includes five helpful appendixes revealing additional powers of the Raspberry Pi, and basic information about things like resistors and how to solder.

One of the coolest things is using the Wii remote to control the robot. If you don’t have a Wii, you can get a remote on line, new, like this one from Nintendo or much cheaper used, at your local Goodwill, or on eBay.

Most of the chapters require that you get or have some sort of equipment or parts to put this thing together. The total cost, though, is not much and everything is readily available. You just have to plan it out a little, checking a chapter ahead for what you might need. And then, go step by step and you will learn a lot about robots, electronics, and the Raspberry Pi. I strongly recommend this experience.

Linux and beyond

When you are done building this, and you want to have some fun with the Raspberry Pi itself, then it may be time for you to play around with Mathematica, Minecraft, Python or other programming, or just use LibreOffice and the other software you can run to write your next novel, run a printer server, build an entertainment center, or who knows what else?

The Pi is a real computer that runs the very powerful and versitile Linux operating system (though it can run other OSs as well). If you haven’t messed around with Linux, now is your chance! And, the software mentioned above, Minecraft, and Wolfram’s Mathematica, comes free and in special more or less kid friendly form, on the Pi.

In any event, if you really want to play around with the Pi, you may want to get a kit that lets you access more of its functions, such as the CanaKit Raspberry Pi 3 Ultimate Starter Kit – 32 GB Edition or the CanaKit Raspberry Pi 3 Kit with Clear Case and 2.5A Power Supply, depending on what parts you want.

See also: A Beginner’s Guide to Circuits and How to learn Python programming

The two big news items for STEM holiday shopping this year are a) Robots have leveled off in complexity and price and b) slime has come of age.

You can go the Mindstorms route with something like LEGO MINDSTORMS EV3 31313 Robot Kit with Remote Control for Kids, Educational STEM Toy for Programming and Learning How to Code (601 pieces), which is very expensive but also very adaptable and part of a large universe. This kit overlaps with the kits used in modern day STEM classes, and there are myriad sensors and other add-ons, also expensive, that you can get. I’m telling you about this because it is the Rolls Royce of robots, but I’m not necessarily recommending it. LEGO seems to be going in a slightly different direction these days, and while Mindstorms is not going anywhere, there is a new animatronic kid on the block.

The newer LEGO alternative robot is the LEGO Boost Creative Toolbox. When Boost first came out about a year ago, it promised to be the start of a whole new LEGO project. The project is taking off slowly, but it is taking off. For a much smaller price than you need to pay for Mindstorms products, Boost provides a programmable versatile robotic kit. The happy go lucky guy you see in this photo can be built, with materials that come with this kit and following supplied instructionws, into a cat named Frankie, a guitar, a roving exploratory vehicle device, and an “auto builder,” which is a device that makes things.

This aftermarket book by a well known LEGO designer provides detailed instructions to use the materials that come with the Boost kit to build a large number of different things, such as doors that open and close, or machines that lift or shoot things, etc. You can use these smaller projects along with our own imagination and a big pile of LEGO bricks to build … whatever.

Also, the Boost project itself, at LEGO, has started to develop ideas, with some degree of instructions, to take kids like this LEGO City Arctic Scout Truck, and build them slightly differently using parts from the Boost kit, to make what would be a normal non-electronic LEGO build into an actual programmable robot. I see a great future for Boost. I am on the verge of figuring out if it is possible to purchase LEGO Boost parts — the ones that are programmable and move tings — in order to further develop this project. One open question in my mind is how Boost software, which runs on a phone or tablet, would distinguish among multiple “hubs” (the key part that coordinates the other parts). We shall see. Anyway, Boost is great fun and very much worth a look.

At a very different part of the Robot spectrum is my favorite, and the very hard to beat in terms of price, buildability, and usability, is the Makeblock Robot Kit. You will want to click around to see what all the slightly different version are, but what you are looking for is probably the bluetooth enabled straight forward robot. There are kits you can get to make the robot walk funny, etc, but the basic robot with the wheels is what you mainly want.

Makeblock is easy to build and will take you much less time to go from zero to full Robot than any of the LEGO products mentioned above. But, as is always true with LEGO, modifying the shape and design is easier with the bircks than with the nuts and bolts used in something like the Makeblock Robot Kit. It is all a tradeoff.

Makeblock uses, as do the LEGO devices, a straight forward, scratch-like drop-the-block style programming system.

The Learning Resources Botley the Coding Robot Activity Set, Code for Kids – Toy of The Year Finalist is a softer, easier, more little kid friendly version of a Makeblock style robot.

It is sturdier than the other robots. It isn’t that the other robots break, but rather, because of the flexible design, they can more easily fall apart. A little kid, say a five or six year old, might cause havoc with a large LEGO build, or they might swallow the small parts with a Makeblock. Botley the Coding Robot is better for little kids, because it gives the basic functionality (sensors, movement, program-ability, etc.) in a device that will hold up to rougher treatment, can’t be easily swallowed, and has no sharp edges. Mostly.

You know those Rube Goldbergesque gravity driven marble kits, where you put the marbles in a thing, and maybe a battery powered screw of Archimedes or something lifts them up, then they come rolling down, etc. etc? They are fun but sometimes don’t go together quite perfectly, or there is some part that comes flying off half the time a marble hits it, that sort of thing?

There are, I think, two flaws in these toys, typically. One is that they use lighter marbles or shot, made of plastic. That is probably a great safety feature, but if they were heavier and better designed they might produce improved results. the other is that the way the parts go together is not well engineered or designed.

Well, the Ravensburger Gravitrax System, which has man expansion sets and add ons, much like the original gravity based fancy toy, Hot Wheels, is more precision designed and does not have those problems. People rave abut the Ravensburger marble toy system, and the system has gotten all the usual awards. I’m pretty sure you are going to want one of these. And several expansion sets.

The day of slime has arrived. Slime is a term referring to a range of substances that have the common property of sliminess. But there may be other properties as well. For example, there is phase-change slime. If you touch it quickly is is hard, but it will otherwise be slimy (uses corn starch). There is magnetic slime, where magnetic iron filings have been mixed into the slime. There is glow in the dark slime.

I really don’t have a specific slime kit I’d recommend, but as far as I can tell, the best to are the NATIONAL GEOGRAPHIC Mega Slime & Putty Lab – 4 Types of Amazing Slime + 4 Types of Stretchable Putty including Magnetic Putty, Fluffy Slime and Glow-in-the-Dark Putty, and another one that I don’t have a link for but you get from the Scholastic book club (you know about that if you have a kid in an American school).

Which reminds me of something else. If you don’t buy a full featured slime kit, you still have to get some form or another of Magnetic Putty. We picked up a can of Magnetic Putty at a state park gift shop last summer. I was thinking it was going to be just another dumb toy that breaks right away. Turned out to be really fun. There are a lot of different forms, look around. It is like magnetic slime but, unsurprisingly, putty like instead of slimy, and amazingly, does not easily dry out.

You could consdider geting one of the Kano Computer Kit , a way to build a $35 computer for a mere $240 bucks. Or ou can get a simple Raspberry Pi 3 Model B Motherboard, which is at the heart of the Kano, and using spare parts around the house, build a working full featured computer. Or, in between and a very good value, you can get the CanaKit Raspberry Pi 3 B+ (B Plus) Starter Kit (32 GB) or similar, which is the Raspberry Pie motherboard with additional parts you need but may not have laying around the house, such as a power supply, an SD card, etc. You will still need a keyboard, a mouse, and a random TV or monitor that takes an HDMI input, but you’ll have the fully functional computer for a good price! The Raspberry Pie operating system (a form of Linux) comes with some pretty cool kid stuff, including a Python programmable version of Minecraft, and Wolfram.

Also have a look at the Wonder Workshop Dash – Coding Robot system for younger kids. This is a classic and well tested robot kit, but I have no direct experience with it. Looks good, though.

I’ve already recommended a rock tumbler as a great STEM gift, and on a related note you might consider National Geographic Geodes , which may or may not come with safety glasses and a hammer. Be careful with this one, but it is fun.

Erector sets are classic and underrated. They have also gotten quite expensive, but also, much more elaborate and probably patience requiring then they ever were. I like the Erector Super Construction 25-in-1 Motorized Building Set and XL 2.0 Robot-Building Kit.

The Scratch programming language is a project set at MIT. Scratch programming involves moving images, called blocks, from a pallet into a work area, hooking them together and maybe changing some values attached to them, in order to develop programs that mainly, but not exclusively, manipulate sprites. (See example of code blokcks above.) The project is located HERE. This is a full object oriented programming language with quite a few features that make it very powerful, for a kid’s toy.

When you use Scratch, normally, you are interacting with the server at MIT via a web page. This allows you to use Scratch on any device regardless of operating system or power, as long as you have an internet connection. It also means the development environment is always up to date. And, on this site, you can interact with all the other scratch coders in the world, and borrow each other’s code, etc.

There is also a version of Scratch that can be run in stand-alone mode on a computer.

And now, there is a version of this stand alone program that is designed to run on a Raspberry Pi.

This version of Scratch has coding elements that control the General Purpose Input Output (GPIO) pins on the Pi. This means you can use the Scratch programming language to interface not merely with sprites on a screen, but with anything physical in the real world, and in so doing, TAKE OVER THE WORLD!!! BWA HAHAHAHA!!

You probably think I’m kidding but I’m not. It is well known that ten thousand chimpanzees randomly banging on keyboards will recreate all the works of Shakespeare. But it will take so long that the Universe will have ended by then. But if you give a few million kids the ability to write programs that interact with the real world it won’t take nearly that much time for them to change the world itself, considerably. Who can even imagine how? But I digress.

Anyway, we have a very easily learned and potentially very powerful software development environment married to a machine that has essentially unlimited abilities to interact with the physical world via GPIO pins, which ultimately can control any kind of switch, motor, sensor, other computer, or anything, that is electronic or that knows something that is electronic.

None of this is sudden. Scratch has been around a long time, and comes from a heritage of software development that goes back to the very beginning of modern languages. The ability to control GPIO like pins is exactly what controllers of all sorts have been doing for years. There has been a stand along version of scratch from early on in the MIT project, presumably with some version predating the on line version. The ability to interact with Raspberry Pi GPIO pins has always been there because you can write special code for Scratch and the actual ability (instead of the merely pedantically potential ability) has been around for maybe a year or so. But over recent months the stand along scratch that you would install on a Raspberry Pi and that has a fairly rich feature set has come to life. Bwa hahahaha!

One way to access this significant power is to buy into the Kano system. You can get a Kano Computer Kit for just under $150. It allows you to build a sort of laptop, including a keyboard and some other stuff (but you supply the screen). The box that holds the Pi, on which Kano is built, has some fancy LED lights that can be manipulated with Scratch. It also comes with a Makey-Makey like sensor that allows some additional interacton. But I’m afraid that’s about it.

I can’t recommend the Kano computer for most users. The markup on the LED lights and the ground fault serial interface device feels like 1000%, though I’m sure it is very nicely packaged and all that. If you go farther, and get the more elaborate Kano Computer Kit Complete , for just under $250, you get some additional LED lights and some sort of microphone. Kano also has a Motion Sensor kit for $23 bucks sold separately, which I think comes with the afore mentioned kits, and there are other things you can get.

In short, Kano looks great, seems nice, may be a really cook kid friendly set of technology, but I’m afraid there will be a close correlation between families that benefit from Kano and families that benefit from the Republican-Trump tax bill.

A Raspberry Pi 3 Model B Motherboard costs about $35. Put that together with stuff you have laying around, like your TV or an extra monitor, a keyboard and mouse, etc. Maybe get some sort of breakout kit such as the Smraza T Type GPIO Breakout board for Raspberry Pi 3 2 Mode B/B+ with 830 tie-points Breadboard and 40 Pin Rainbow Cable. This allows you to more easily attach things to the Pi. The Pi-3 already has internet and Bluetooth capabilities.

The most current version of the Rapsperry Pi operating system, a form of Linux called Raspbian (for Rasperry and Debian, a classic form of Linux) has the offline Scratch language built in. Go to this site to learn more about that. Then you can have code blocks like this:

Depending on that GIPO pin number 2 is hooked to, you can now TAKE OVER THE WORLD … BWA HAHAHAHAHA!!!

But seriously, this is very cool, and very powerful.

I predict that in the not too distant future, the Internet of Things will be operated with, essentially, the Scratch programming language. It is accessible to regular people, allowing them to modify their home automation, and allows companies that install this sort of thing to have much more powerful technicians with less effort on training. Think of Scratch on controller software to be a bit like the old Microsoft Windows macros — remember that? — back when that technology was usable, and in fact used, by people who knew virtually nothing about the computers they were using.

What could possibly go wrong?