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January 2nd, 2017

Bot of Course

I’m glad I got started with Arduino, because it helped me get back to learning C. It’s moderately enjoyable to learn C without any external apparatus, but somehow it’s more fulfilling when you add a second device (after your PC) at the end of a USB cable.

I’m still going through Ladyada’s tutorials. She can really teach. They say those who can’t, teach, so if you turn that logic around and twist it, maybe it makes sense that she’s an exceptional teacher, because she’s not one of those who can’t. She’s the owner of Adafruit Industries, which is a well-known supply house for tech hobbyists. Her PR blurb descibes her as an “MIT hacker and engineer.” I suppose she is overqualified to teach.

I have learned how to make the Uno print things out and do simple math. Naturally, I find it almost impossible to use the code she provides. I can’t take that kind of boredom. I have to make changes. I suppose that’s a good thing, because if you just copy and paste, all you learn is copying and pasting.

I’m thinking it may be time to build a robot. I guess that seems like a surprising jump, given that I can’t do much of anything with the Uno. But it turns out building and programming a robot is really easy, mostly because thousands of other people have already done the work and published the important parts online. Programming robots is one of the main ways people get good at Arduino.

I started looking at robots, and most of them were horrible. There is an Arduino-brand robot, and it looks like motorized ashtray. It’s a circular PCB with two wheels. I’m sorry; I don’t care how great it is as a teaching tool. I’m not going to be happy teaching an ashtray how to navigate the floor of my office, especially now that I don’t smoke cigars.

I still can’t believe I put dozens of Cubans by the side of the road for the garbage people. Those were some fine smokes. I just looked up the statute of limitations, and I’m safe, so yeah, I bought a lot of Cuban cigars. Take that, coppers. Not that the government cares. I’ll bet no one has ever been so much as fined.

There’s a robot called the “BOE bot,” and “BOE” stands for “Board of Education.” I guess that means it’s overpaid, can’t be fired for incompetence, and teaches kids they should consider being gay. The bot looks pretty boring. It’s sort of a little cart that putts around dodging things and following lines painted on the floor.

Here’s what caught my interest: self-balancing robots. These are robots that exist in unstable equilibria. They balance on two wheels or some other inadequate type of support. Cut the power, and they fall over. They’re much neater than four-wheeled robots because every time you turn them on, they demonstrate the possibilities of modern hobby electronics. Simply balancing and moving around are impressive tasks for unstable robots.

I looked at a bunch of these robots on Youtube. Most involve three flat platforms arranged like a two-story building. Wheels and motors go under the lowest platform. Batteries go on top. Each wheel has its own motor. To do it right, you should use steppers, but people use crappy Chinese hobby motors too.

Determining what kind of robot was best was not easy, because people have posted videos of bad robots during the last year, while others posted videos of superior robots as long as six years ago. My natural tendency was to look at robots which had been built recently, but then I would dig up older videos and learn that better designs had been around for quite some time.

I don’t know why people continue making bad robots. Everyone has Google.

Some of the robots are really awful. They fall down, or they can’t maneuver. Some have wires attaching them to computers. Come on! That’s insane. Who wants a robot that can only walk three feet?

One of the neatest robots is a kit job, and it’s called the “B-robot.” The name alone justifies the purchase. Many self-balancing robots wobble and don’t maneuver well, but the B-robot is nimble and sure of itself. It has an arm, too, so if it falls, it can use the arm to boost itself while it rights itself. Unfortunately, it costs $125, which is like $121 more than I want to spend.

I guess the next version will be the Dude-b-robot.

Why get a kit? Because every robot you didn’t design yourself is really a kit. Even if you make the parts, you’re using someone else’s design, so buying a kit is not cheating in any important way.

When I first learned it was possible to build two-wheeled balancing robots, I was surprised. After I got used to the idea, I started to wonder why I couldn’t built a one-wheeled robot. It could change direction faster. If you can balance with regard to one axis, you should be able to balance with regard to another at the same time. That’s what I thought. Then I checked. Sure enough, it has been done.

In my uneducated opinion, the best type of “one-wheeled” robot doesn’t have wheels. It uses a ball instead. It’s unclear who invented it. Various people seem to be trying to take credit. You put three or four steppers in the base of a robot, and you arrange them so they turn a ball trapped under them. The robot balances on the ball, and it can move in any direction by turning it.

A nut genius in England spent an incredible amount of time designing his own copy of BB-8, the small robot in the new Star Wars movies. A ball bot may have a ball which is mostly contained in the robot’s body, but you can also make a small robot which rests high on the upper hemisphere of a ball.

I guess I should be satisfied with a two-wheeled robot to start, because it has been done a million times, and there is an appreciable chance that I’ll be able to make it work. Ball bots are intimidating.

Once you get your robot on its feet, so to speak, you can start doing mods. You can put sensors on a little “head” at the top so it tracks objects. You can put a laser on top of it and shoot at things. You can put a camera on it. You can add a cup holder. You can add various types of displays. You could send the robot to your wife with a display reading, “Help. Out of toilet paper.”

Is it useful? Not in the slightest. At least I don’t think so. But it would teach me a lot without boring me too much.

I hesitate to put this in print, because some idiot may think it’s a great idea, but I believe you could use something like this for home defense. It’s possible to blind people with lasers. It works so well, it’s considered a war crime. You could send a robot out into your yard to shoot lasers at the faces of violent intruders.

I’m not suggesting you do that, because it’s vicious idea, but I suppose it would work. I don’t know how easy it is to get a laser strong enough, or whether it could be carried on a robot a person could reasonably be expected to build at home.

On the whole, I still prefer sharks. Call me a throwback.

It would be neat to make a robot that tracks balloons and shoots them with a laser. That’s actually possible.

I don’t know. There must be some use for these things.

Perhaps for now I would be smart to learn simpler things. I’m having delusions of grandeur.

I may have to trim my expectations, but there is no reason why I can’t build some sort of reasonably interesting robot. If I succeed, you will know all about it.

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