Robotics Crash Course, Part 2

Ok, so if you've been following us from part 1 of the crash course, you'll know that we're beginning to build a very simple robot. So simple, it's effectively a laptop duct taped to a robot vacuum cleaner. Since Damon has done such a good job of documenting the process up to here, i'm just going to refer you to his Instructables page. But let's talk about the important improvements in this step...

In case you're wondering, i did the optional power step he describes. *THIS* is why I'm using the OLPC laptop for now: nothing else is this flexible with their power inputs. I can't hook up anything else this easily. My eeepc 701 for example wants a nice clean 9.5 v at 2.5 amps. Not happenin' (yet)...

The really important thing to note here is we have just potentially made our robot self-sufficient. The robot base AND the laptop can now dock with the docking station and recharge their batteries whenever they see fit. You could easily make the "low battery" warning trigger the dock-seek subroutine, set it up on a schedule, whatever. Point is: our robot can now (potentially) function indefinitely without the need of a human to refuel it. Obviously it can't wander off too far, or it won't make it back to the docking station, but hey, big step here.

Of course, there is a really big drawback here as well: the laptop will suck power from the robot constantly. Which means less battery life for the robot. We'll fix that in our next step...

The other thing to note here is we now have some nifty software! It's not perfect, but it's better than VNCing into the laptop and some other craziness. Pretty basic for now, but we'll upgrade that later. It's made in Python, which means it'll run on pretty much anything with a little tweaking. It also means it can run a tad slow, but for now it works. Much expansion here in the next step too...

So tune in next time, you damn kids with your music...

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Robotics Crash Course, Part 1

Ok, let's say you wanna build some robots. Maybe you want something to automagically feed the dogs for you. Maybe you want something to fetch you a beer. Some sort of robo-butler, perhaps. Or maybe you're looking at a world domination bid, whatever. Let's build some robots.

Oh wait, all I know about robots come from movies and TV. That might be a problem. Better start small and simple. Crawl before you walk before you run and so on. How's about a simple as hell, darn-near idiot proof, ultra-n00b's guide to building your first robot?

Hell, why not...

Turns out that robots, much like everything else, are nothing more than a carefully arranged pile of parts, held together by screws and software. So the question is: how "made from scratch" do you wanna go? If you're really ambitious, you could go mine some copper ore, refine it into wire, build the motors yourself, and so on. I don't know about you, but that ain't happening...

You could buy some basic motors and wheels and bearing and all that junk, and build a robot up from the ground up. Maybe, someday. Not today...

How about we cheat a little? Let's take a ready-built robot: the iRobot Create. It's basically one of those robot vacuum cleaners, except without the vacuum cleaner.



Yay! We have a robot now! Let's take over the world! Ok, well, not quite. It's a robot by some measure of the word, but it doesn't really do anything useful. Yet...

Here's what it DOES do usefully: moves around based on serial commands, avoids obstacles, provides battery power from it's 14.4v battery to anything you can wire into the cargo bay connector, and it can find it's own charging station.

In fact you can pull it out of the box, slap in a battery, and hook the included cable up to the serial port of a computer, and drive the little robot with the computer!

Now imagine you have a laptop. If you don't know how to do it by now, it's pretty easy to connect to a laptop and remotely control it. You can use Remote Desktop Connection or VNC and control it like you were sitting right there if you wanted to keep it simple (and avoid writing code). Most laptops come with a webcam these days, and usb webcams are cheap. Laptops have wireless too...

...so duct tape the laptop to the robot!



You now have a self-mobile, remotely connectable, WiFi enabled robot with webcam and microphone. It can find it's little charging station all by itself, and can avoid obstacles in some fashion. It even has a nice juicy screen to display stuff to people, and speakers to talk or play music with. It ain't R2-D2, but you could easily use it as a remote surveillance / telepresence type thingie. Hostage negotiators could send one in to teleconference with the bad guys, while SWAT sneaks one in the back to map out the interior and looks around. In this case, it's an OLPC XO laptop, which is nifty because of the swiveling screen, built in WiFi, webcam, microphone, and uber-long battery life. However, any laptop you have laying around can be used, but it seems like a cheap little netbook is particularly suited. I used the included iRobot cable and a cheap serial-to-usb converter to connect the robot to the laptop.

Now, granted, our robot still isn't much to brag about. But if you didn't get 100 ideas about how to IMPROVE on this little thing, you need to put down the internet and step away. Slowly.

That's the beauty of this thing: it's a simple yet marginally useful and functional platform to start with. Building a robot from scratch to this point is a long a frustrating process for beginners, and is usually the main barrier keeping them from really building anything. But now, we can focus on learning about the smaller and funner things. As time marches on, this little platform will become insufficient. By then, I'll be ready to build one from scratch.

And there you have it. With about $400 and a bit of ducktape, you can "build" a somewhat useful robot! Don't worry, more to come. Gotta make it cooler after all. Relatively soon.

And if this looks oddly familiar, it's supposed to. I'm going to be building up his Fido robot (or as close as I can) as my personal starting point, and then tweak/hack/rebuild from there. I don't want nobody thinking I'm stealing credit for this, give credit where credit is due and all that happiness. Updates during the process are the plan, but plans never survive first contact, so we'll see when they get up.

and riboflavin...

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[CTRL]+[ALT]+[DEL]

*tap tap tap* is this thing on?

Yea, ok, bit of an abandoned blog. I'll try to fix that. Geekiness must be had. Geekiness WILL be had. So here's the situation:

I have an iRobot Create
I have an OLPC XO laptop
I have a Logitech Orbit AF
I have a USB generic webcam w/IR LEDs
I have a USB missile launcher
I have 2 arduino boards
I have a compass sensor
I (will soon) have a sonar sensor
I have a 4X20 Character LCD display

One way or another, all that crap is getting stuck together. Should be fun to figure out that game of electrical tetris. Stay tuned...

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