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Compact Sumobot: Dozer

TRS is planning a sumo competition soon, and I've just realized I haven't been very active in my bot building at all.  The last meet-up included some basic H-bridge and sensor instruction, so I assume that everyone is expected to use small DC motors in the bots.  The only rules I've heard however, have been that the final entries must fit in a 6"x 6" square.  After scrounging around my parts bins, I can't find any handy DC motors that would work properly as a pair.  So I'm "cheating": servos it is!  I hope it isn't decided to be unfair, the torque in these things is killer.  We shall see.


In the interest of keeping the bot as compact as I can, I'm going for an all hot glue and Velcro method.  The control board is a simple piece of Radio Shak protoboard that Rob kindly provided a few weeks back, and I'll be driving the servos and running the microcontroller from separate power sources.  I'm trying out a Dorkboard for the brains, as the Arduino servo libraries are killer, and I've been meaning to work out the interrupt issues from ADAM anyway.  Speaking of ADAM, I've officially scrapped him for parts.  Again.  Poor lil' guy... never even had a chance.


Anyway, here's a few pics of the little bit of preliminary work I've done so far.


I'm spending most of the time so far laying out all of the little bends in the wiring.  It's amazingly helpful to spend the extra few minutes on the layout so far, since I won't get so lost in the tangle I usually find myself in trying for a more "universal" design.  You can see the headers in use for left and right servos, and the small header delivering power to them up front.  Not much to look at, but sumo-bots generally aren't.


The next steps are to work on the sensor deployment and write some code.  I'm not sure what we're laying out the arena edges with yet.   That would be helpful, as if it's something I can detect with an optical sensor looking at the ground, I can keep this guy in the ring.  It's really embarrassing to turn on your creation, step back, and have it happily escape the area.  No freedom for you little bot!



Been working through the wee hours.  Go insomnia.  Attempted to rig up an LM7805 regulator circuit to run the Dorkboard off the same battery as the servos.  I figured it'd be isolated enough from the current draw, but I was totally wrong.  Poor little guy can't keep up with the surges the servos pull when you move them, and the Dorkboard resets.  Bah!  The wiring was suer tight too... Oh well.  I'll just adapt what I have in there for running off a 9V cell.



AVR Programming for the Fireflys

I really need to build a better harness to program these things before I solder them up.  Once I've got the LEDs soldered on, forget it.




Firefly Jars - SMD Soldering Fun

A few years back, I made a firefly jar for Kate in an ultimately successful attempt to show her how unbelieveably awesome a guy I was.  It helped that I was unemployed at the time, since these suckers are incredibly time consuming.  Now that relationship success is mine, I've been tasked with making six more for the impending wedding.  Yay!

After a quick Digikeying, I've been working on all the great assembly stuff.  The hardest part is working with the LEDs.  These suckers are SMALL.

I've found the best way so far of manipulating these little guys is by microclip.  Using magnet wire keeps the LED and wires as invisible as I can get in the jar, and the clips are easier to use then my fingers when soldering them on.

Yeah, I know.  Use the tiniest tip you can on your iron, and keep the temp below 530ish F.

It's a pain, but ultimately worth it.  Especially when you get to show them to family, and they see the awesome effect made by the code off of the Instructables link.  Quite nice!

It also helps to have a clean, well organized bench to work on.  At least I've made a bit of progress there recently.  Finally decided to mount as much as I can to the walls, and it's a HUGE help.

So until next time, I'll be plugging away a few LEDs now and then.  At least I've got like two months to finish!


User Interfaces: Do We Fight Innovation?

Installing Ubuntu 10.04 on my desktop was my afternoon project once I got home today, and it went swimmingly.  They've really made it a streamlined process to get from A to B for the end user, and I like most of the improvements (although integrating "social" aspects and the "Ubuntu One" cloud thing I'm undecided on so far).  The first thing that I noticed though wasn't the slick new skinning, or the crazy Prince inspired color scheme (Purple Rain anyone?).  It was the fact that they moved the window controls to the left side of the apps, instead of the usual right.

I immediately started searching for a way to move them to the right side again, but it seemed like I was stuck with it.  When I finished the obligatory "apt-get update", my cursor immediately snapped to the upper right corner of the terminal, only to be left in the cold of an empty title bar.  I was starting to get annoyed.  Thinking I couldn't be the only one pissed here, I fired up the ol' browser and started to Google for an answer to why I had been forsaken to the hell of Bizarro Desktop.

Then I started to actually think about what was happening here.  Why am I so annoyed by such a small detail?  Mac users deal with it after all.  Who says it's better to have the controls on one side or the other anyway?  I honestly cannot come up with a single argument to support controls on the right except for the hollow "that's what I'm used to" that every other Windows user would probably say to this.  And actually, as briefly mentioned by Ubuntu Overlord Mark Shuttleworth in a bug report on the subject, this does open up some extra room for notifications, widgets, etc.:

"Moving everything to the left opens up the space on the right nicely, and I would like to experiment in 10.10 with some innovative options there. It's much easier to do that if we make this change now. I appreciate that it's an emotive subject, and apologize for the fact that I haven't been responding in detail to every comment - I'm busy moving house this week. But the design team is well aware of the controversy, your (polite) comments and more importantly *data* are very welcome and will help make the best decision." - Mark Shuttleworth

So this begs the question: If people are so peeved by such little changes, what can be done to create new and improved UI designs in the future?  Let's say something as cool as the interfaces in Minority Report, Iron Man 2, and The Matrix become a reality.  Are people really going to want to use them enough to switch their standards?  Are we going to be stuck in the 2D desktop forever?  The 3D attempts usually die out after a few pretty screenshots.  I'd absolutely LOVE to see some of these become more useful then a burst of wow factor to impress friends and coworkers, but the truth is they tend to be slow, inefficient, and useless for day to day tasks.

Someday, things may change.  Hopefully, we're not shooting ourselves in the foot because of what we're "used to".


Treaded Tank-like Chassis and Other Such Madness

I decided a few weeks back when I had some spare time that I was going to rebuild the bot chassis design again.  After talking with some guys in the office, and a quick trip to Fry's, I picked up a Tamiya tracked chassis kit, and a dual motor gearbox.

Behold the mighty powers of Google SketchUp!


Again, it will be Arduino based methinks.  The servo on the top platform should be a good spot for some sensors, cameras, death rays to be mounted as well.

On similar, vaguely related topics... I started experimenting with forging and fabrication of steel and aluminum stock again.  I first tested the waters by taking a piece of scrap welding bar and filing out a crude "appendage" for a future project:

The copper piece on the back of the blade is a crunched up pipe cap I mangled.  That skill needs some work.

Next, I went on to a bigger, more interesting project.  I heard old files were a great source of high-carbon steel.  In order to work them, you have to anneal them by getting them cherry red for around 30 minutes or so, then letting it air cool slowly.



Bad phone pictures, but I'm ready to heat treat this sucker and pin in some nice wooden handles.


For the record, the bot name "Mr. Stabby" was around well before the NY Resistor guys made their phone controlled shiv machine.  So I get to use it as well.  :)