Want To Learn Binary? Draw Space Invaders!

This was the week that I accidentally taught my nearly ten-year-old son binary. And I didn’t do it on purpose, I swear.

It all started innocently enough. He had a week vacation, and on one of those days, we booked him a day-course for kids at our local FabLab. It was sold as a “learn to solder” class, and the project they made was basically a MiniPOV: eight LEDs driven by a museum-piece AVR ATtiny2313. Blinking lights make a pattern in your persistence of vision as you swipe it back and forth.

The default pattern was a heart, which is nice enough. But he wanted to get his own designs in there, and of course he knows that I know how to flash the thing with new code. So I got him to solder on an ISP header and start drawing patterns on grids of graph paper while I got the toolchain working and updated some of the 2000’s-era code so it would compile.

There’s absolutely no simpler way to get your head around binary than to light up a row of LEDs, and transcribing the columns of his fresh pixel art into ones and zeros was just the motivation he needed. We converted the first couple rows into their decimal equivalents, but it was getting close to dinner time, so we cheesed out with the modern 0b00110100 format for the rest. This all happened quite organically; “unintentional parenting” is what we call it.

While we were eating dinner, I got the strangest sense of deja vu. When I was around ten or eleven, my own father told me about the custom fonts for the Okidata 24-pin printer at his lab, because he needed me out of his hair for a while, and I set out to encode all of the Hobbit runes for it. (No comment.) He must have handed me a piece of graph paper explained how it goes, and we had a working rune font by evening. That was probably how I learned about binary as well.

Want to teach someone binary? Give them a persistence of vision toy, or a dot-matrix printer.

(Art is from a much older POV project: Trakr POV — a hack of an old kids’ toy to make a long-exposure POV image. But it looks cool, and it gets the point across.)

Car Driving Simulators For Students, Or: When Simulators Make Sense

There are many benefits to learning to fly an airplane, drive a racing car, or operate some complex piece of machinery. Ideally, you’d do so in a perfectly safe environment, even when the instructor decides to flip on a number of disaster options and you find your method of transportation careening towards the ground, or the refinery column you’re monitoring indicating that it’s mere seconds away from going critical and wiping out itself and half the refinery with it.

Still, we send inexperienced drivers in cars onto the roads each day as they either work towards getting their driving license, or have passed their driving exam and are working towards gaining experience. It is this inexperience with dangerous situations and tendency to underestimate them which is among the primary factors why new teenage drivers are much more likely to end up in crashes, with the 16-19 age group having a fatal crash nearly three times as high as drivers aged 20 and up.

After an initial surge in car driving simulators being used for students during the 1950s and 1960s, it now appears that we might see them return in a modern format.

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A New Educational Robotics Platform

When looking for electronics projects to use in educational settings, there is no shortage of simple, lightweight, and easily-accessible systems to choose from. From robotic arms, drones, walking robots, and wheeled robots, there is a vast array of options. But as technology marches on, the robotics platforms need to keep up as well. This turtle-style wheeled robot called the Trundlebot uses the latest in affordable microcontrollers on a relatively simple, expandable platform for the most up-to-date educational experience.

The robot is built around a Raspberry Pi Pico, with two low-cost stepper motors to drive the wheeled platform. The chassis can be built out of any material that can be cut in a laser cutter, but for anyone without this sort of tool it is also fairly easy to cut the shapes out by hand. The robot’s functionality can be controlled through Python code, and it is compatible with the WizFi360-EVB-Pico which allows it to be remote controlled through a web application. The web interface allows easy programming of commands for the Trundlebot, including a drag-and-drop feature for controlling the robot.

With all of these features, wireless connectivity, and a modern microcontroller at the core, it is an excellent platform for educational robotics. From here it wouldn’t be too hard to develop line-follower robots, obstacle-avoiding robots, or maze-solving robots. Other components can easily be installed to facilitate these designs as well. If you’re looking for a different style robot, although not expressly for educational purposes this robotic arm can be produced for under $60.

FET: Fun Endeavors Together

Last time, we’ve looked over FET basics, details, nuances and caveats. Basics aren’t all there is to FETs, however – let’s go through real-world uses, in all their wonderful variety! I want to show you a bunch of cool circuits where a friendly FET, specifically a MOSFET, can help you – and, along the way, I’d also like to introduce you to a few FETs that I feel like you all could have a good long-term friendship with. If you don’t already know them, that is!

Driving Relays

Perhaps, that’s the single most popular use for an NPN transistor – driving coils, like relays or solenoids. We are quite used to driving relays with BJTs, typically an NPN – but it doesn’t have to be a BJT, FETs often will do the job just as fine! Here’s an N-FET, used in the exact same configuration as a typical BJT is, except instead of a base current limiting resistor, we have a gate-source resistor – you can’t quite solder the BJT out and solder the FET in after you have designed the board, but it’s a pretty seamless replacement otherwise. The freewheel (back EMF protection) diode is still needed for when you switch the relay and the coil produces wacky voltages in protest, but hey, can’t have every single aspect be superior.

The reason you can drive it the same way is quite simple: in the usual NPN circuit, the relay is driven by a 3.3 V or a 5 V logic level GPIO, and for small signal FETs, that is well within Vgs. However, if your MCU has 1.8 V GPIOs and your FET’s Vgs doesn’t quite cut it, an NPN transistor is a more advantageous solution, since that one will work as long as you can source the whatever little current and the measly 0.7 V needed.

Continue reading “FET: Fun Endeavors Together”

The Singularity Isn’t Here… Yet

So, GPT-4 is out, and it’s all over for us meatbags. Hype has reached fever pitch, here in the latest and greatest of AI chatbots we finally have something that can surpass us. The singularity has happened, and personally I welcome our new AI overlords.

Hang on a minute though, I smell a rat, and it comes in defining just what intelligence is. In my time I’ve hung out with a lot of very bright people, as well as a lot of not-so-bright people who nonetheless think they’re very clever simply because they have a bunch of qualifications and diplomas. Sadly the experience hasn’t bestowed God-like intelligence on me, but it has given me a handle on the difference between intelligence and knowledge.

My premise is that we humans are conditioned by our education system to equate learning with intelligence, mostly because we have flaky CPUs and worse memory, and that makes learning something a bit of an effort. Thus when we see an AI, a machine that can learn everything because it has a decent CPU and memory, we’re conditioned to think of it as intelligent because that’s what our schools train us to do. In fact it seems intelligent to us not because it’s thinking of new stuff, but merely through knowing stuff we don’t because we haven’t had the time or capacity to learn it.

Growing up and making my earlier career around a major university I’ve seen this in action so many times, people who master one skill, rote-learning the school textbook or the university tutor’s pet views and theories, and barfing them up all over the exam paper to get their amazing qualifications. On paper they’re the cream of the crop, and while it’s true they’re not thick, they’re rarely the special clever people they think they are. People with truly above-average intelligence exist, but in smaller numbers, and their occurrence is not a 1:1 mapping with holders of advanced university degrees.

Even the examples touted of GPT’s brilliance tend to reinforce this. It can do the bar exam or the SAT test, thus we’re told it’s as intelligent as a school-age kid or a lawyer. Both of those qualifications follow our educational system’s flawed premise that education equates to intelligence, so as a machine that’s learned all the facts it follows my point above about learning by rote. The machine has simply barfed up what it has learned the answers are onto the exam paper. Is that intelligence? Is a search engine intelligent?

This is not to say that tools such as GPT-4 are not amazing creations that have a lot of potential to do good things aside from filling up the internet with superficially readable spam. Everyone should have a play with them and investigate their potential, and from that will no doubt come some very interesting things. Just don’t confuse them with real people, because sometimes meatbags can surprise you.

Cargo Culting And Buried Treasure

I have no idea how true the stories are, but legend has it that when supplies were dropped on some Melanesian islands during WWII, some locals took to replicating runway signs in order to further please the “gods” that were dropping them. They reportedly thought that making landing strips caused laden airplanes to visit. Richard Feynman later turned this into a metaphor about scientific theory – that if you don’t understand what you’re doing deeply, you may be fooling yourself.

I’d like to be a little bit more forgiving of adherents of technological cargo cults. Because the world around us is very complicated, we often just take things as they are rather than understanding them deeply, because there’s simply only so deep you can go into so many fields.

Is someone who doesn’t know the i386 machine language cargo-culting their way through a job as a web backend developer? Probably not. But from the perspective of an assembly-language programmer, any of us who write in compiled or interpreted programming languages are cargo-culting coding. You don’t need to understand a cell phone to dial home, but can you really say that you understand everything about how one works?  Or are you just going through the motions?

So while some reliance on metaphor and “well, it worked last time” is perfectly normal, I think noticing when you cargo-cult is also healthy. It should also be a warning sign, or at least a flag to remind yourself that there may be dragons here. Or maybe just a buried learning opportunity, the X that marks the spot where digging deeper might be productive.

Learning By Playing

Summer break has started over here, and my son went off to his first of a few day-camp-like activities last week. It was actually really cool – a workshop held by our local Fablab where they have the kids make a Minecraft building and then get to 3D-print it out. He loves playing and building in Minecraft, so we figured this would be right up his alley.

TinkerCAD model of a Lego Minecraft fox. Kiddo trifecta!

I had naively thought that it would work something like this: the kids build something in Minecraft, and then some software extracts the build and converts it into an STL file. Makes sense, because they already are more-or-less fluent in Minecraft modelling. And as I thought about that, it was a pretty clever idea.

But the truth was even sneakier. They warmed up by making something in Minecraft, then they opened up TinkerCAD, which was new to all of the kids, and built a 3D model there. Then they converted the TinkerCAD models into Minecraft, and played with what they had just built while the 3D printers hummed away.

The kids didn’t even flinch at having to learn a new 3D modelling tool, and the parallels to what they were already comfortable doing in Minecraft were obvious to them. My son came home and told me how much easier it was to do your 3D modelling in “this other Minecraft” – he meant TinkerCAD – because you don’t need to build everything out of single blocks. He thought he was playing games, but he’d secretly used his first CAD tool. Nice trick!

Then I look back and realize how much I must have learned about computers through playing as a kid. Heck, how much I still learn through playing. And of course I’m not alone – that’s one of the things that shines through in a large number of the projects we feature. Hack on and have fun!