It isn't too bright (I used a 4 AA battery supply, so about 6V, and there are 52 LEDs in parallel on the tree), but it does provide a nice ambient kind of glow to a dark room (you almost can't see it in the light). That was the goal, I guess, and I put in a Joule thief circuit in hopes that it would extend the battery life a little, though I'm not feeling up to actually testing it.
Though this one was a bit of a pain, I have some ideas on how to improve on the design and I'm definitely going to make some more similar LED artstuffs in the future.
EDIT: So like I thought, it is pretty much for certain that the Joule thief is kind of silly in this circuit, because it doesn't seem to actually be doing anything useful. Also, the lifetime on the lamp isn't too great. It'll last through a whole night, I guess, but come up kind of dim in the morning. If you turn it off for a bit it gets brighter again, but near the end of the battery life that extra brightness doesn't last long. One day in the future, when I have completed a number of EE and physics courses and have hopefully gained some understanding of what it is I'm trying to do, I will redesign the guts of this tree.
So the main, big project I'm working on now is getting kind of frustrating, and I thought I'd take a break tonight with a few quick projects.
I started with a empty box of chocolates from Trader Joe's. It had an adorable design with a porthole in the middle, and I had to use it somehow. Using a dremel I cut the bottom of the box off, and then I glued on three magnets with super glue. The top fits snugly onto the bottom, so all that was left was to find a picture for my picture frame.
Big Daddy character copyright 2k, of course.
Anyhow, since that project had just about two steps, I needed something else to do. Half an hour on instructables (an amazing site, by the way) reminded me that I had always wanted to build a Joule Thief. It is a remarkably simple project, but I still feel proud of myself.
You basically need an NPN transistor (2N3904), an LED, an old battery, a small toroid magnet, a 1kohm resistor, and thin wire. Optionally, you'll want a AA battery holder and a switch. I already had everything except the toroid.
Of course, the Radioshack store people had no idea what I was talking about when I asked for the toroidal magnet thing, so I found the part number myself. If you have to go to Radioshack and pay their inflated prices, here it is. Note you can probably try to use the 273-108 if you can't find the 273-109 in stock.
The 2 AA battery case leaves plenty of room to house the battery and the innards (in the second battery's place). It is a little black and boxy, but you can decorate it with stickers and such.
And now, for robots! To start, we have a basic obstacle-avoiding, color-detecting robot. He was the final project for my ENGR 150 class, a basic intro to robotics class that was definitely worth taking. He navigates with a SICK LMS 200 laser rangefinder, and sees color with a basic webcam. His brain is a laptop, and his body is a Pioneer. Oh, and we used whatever sound files we found already on the laptop (from somebody else's project), hence the robot's lingual confusion. (Also, sorry that it is unedited...I ripped these from facebook, and I couldn't get them to import into iMovie.)
And finally, more robots! This is a robot from the lab where I work, a CREATE roomba from iRobot with a webcam and a Netbook. A quick google search shows that this is getting to be quite a popular robot setup: relatively cheap, very easy to use, and versatile. This guy also hooks up to a Garmin GPS, not shown. (There's no sound in the video, by the way).
So yeah, I that's all I have for now, but there is some pretty awesome stuff in the works, which I hope to show you soon!
Introducing...Swervy! Swervy is a robot that Allen and I built this last semester. On occasion, I also call him Screwy and Scurvy. Here are some tech specs for his current configuration:
-Limit switches (2) -Power Wheels gearboxes and motors (Fisher Price, 2) -Power Wheels battery -The Arduino Diecimila -IR Receiver (from the First Robotics Kit, 2008) -Victor 884 motor controllers (2) -7.2V Ni-Cd rechargeable battery pack
Here's a short video demonstrating Swervy's current capabilities.
Finally, while we're already talking 'bout robots, here is a photo of the LAGR from Carnegie Mellon, which I was working with last semester.
Next up on the list of things to hasten the coming of the robot revolution: networked roombas.
It isn't easy to describe the FIRST National Championships in Atlanta, Georgia on account of that event's scope and size, so I'm going to start with a few things in list form.
-Four divisions with 87 teams each (total 348 teams) -The Georgia Dome is humongous -Both flights and the our hotel were full of FIRST teams
We did exceptionally well, ranking 23rd of 86 teams in our division. You can see our videos, as usual, at thebluealliance.net (scroll down to "Galileo Division"). It was a complete turnaround from the Los Angeles Regionals, and we even installed a shooter and scored a few balls.
And now I will bombard you with photos:
The man in the center around which we are crowding is Dean Kamen, who among a great many other things invented the Segway. His company, Deka, recently developed a highly complex prosthetic arm.
I'm still at a loss of how to sum this up, so I'm just going to leave you with this: FIRST is a great experience, and to anybody interested in robotics who isn't already involved with FIRST, I encourage you to become involved, whether as a mentor or as a student. There isn't anything quite like it.
Somebody is making rounds about campus, spreading unwarranted amounts of hilarity. The list of victims is long; the list of suspects, short. Who is this vandal? Who dares add character to miscellaneous objects in our surroundings? Nobody knows when we will come face to face (or eye to googly-eye) with the Googly Eye'd Bandit...
On a completely different note, here is our president, looking surprised.
Finally I'd like to give you a preview of what Allen and I are rushing to finish before the end of the semester (click to view in full size):
An Introduction... Last year, I joined my high school's FIRST Robotics team as a senior. This year I have returned to serve as a college mentor, because FIRST is the most awesome competition I have ever participated in.
In the way of our wins to losses ratio, we may leave something to be desired. But in our defense, we're entirely student-led (the force behind many high ranking teams are professional, adult mentors) and our funding and facilities are limited (we own a drill press and table saw, while some teams own a warehouse and their own CNC). In any case, FIRST makes it very clear that FIRST is not about points, but rather, gracious professionalism. The key thing, I guess, is that our team is all about the hands-on experience and having a lot of fun.
FIRST 2008: Overdrive The point of last year's competition was to zoom around a track whilst herding and throwing large (think pilates +) balls. We aimed for just the first goal with a tiny, ~50lb robot called the "Rapid Rabbit Robot" that reached speeds of about 13 mph. It turned out to be a bit difficult to control on the field, but was great as a motorized chair to ride around campus. You can see videos of us at the 2008 LA Regional at thebluealliance.net (I'd suggest Qualifications 36).
Our major success of 2008 was a giant castle set piece that framed our pit area. To complete the theme, we introduced our team mascot (the knight) and distributed inflatable plastic swords. As a result we won the Spirit Award, and began our team tradition of winning something in a category unrelated to robot performance.
FIRST 2009: Lunacy This year's competition is defined by low friction wheels and a low friction playing field. Robots drag trailers behind them, and points are scored when balls (whether launched by a human player or robot) are scored in the opponent's trailers. We decided to aim for a full-fledged robot this year (with a manipulator and all) as illustrated in this beautiful CAD drawing by our very own Ryan Abrams (who is off to UC Berkeley next year!).
Here are some (slightly blurry) photos:
Unfortunately, we never really got the manipulator working. And we came in 20lbs overweight, AND we didn't bother weighing it until Robot Inspection and Check-in Day...You can see our scoring breakdown for the LA Regionals here, though no video is up yet. The bottom line is that the one match our alliance won is the match for which we were busy fixing up our 'bot (so they set up a dummy wheel to hold up the trailer instead). To go into some detail, we didn't even move for about half the matches.
On a brighter note, Eli won the Animation Award (a FIRST-related competition) for his 30 second piece envisioning a new kind of wall.
Atlanta, Georgia Since the National competitions are usually underpopulated, it is possible to get in by lottery. As luck would have it, we got that privilege this year, and so portion of Team 1836 is flying out to Atlanta next Wednesday (myself included). It'll be a challenge, considering we need to install and test a replacement manipulator mechanism, do routine maintenance, and leave time for the programmer to calibrate her code (and I'm talking about a first-time calibration, not a fine-tuning calibration; the camera mount angle, motor values, color threshold definitions, and other such constants are are based on my best estimates). Oh well, I guess I like the adrenaline rush. Definitely better than spending my week falling asleep in lecture!
Some more team info... As listed on our snazzy red coveralls, our current team sponsors include: -The Mitchell Academy of Science and Technology and the Leslie Zola Science Scholarship, who graciously provide us with funding -The wonderful Findlay's Machine Shop, where we get our parts cut and drilled -Z Manufacturing Inc., where the amazing Stephen Ziolkowski welds our 'bot together -Perceptronics Solutions, for whom I now work (with special thanks Onur Sert, our first adult mentor) -And finally the Orthopaedic Hospital of Los Angeles, who have provided us with additional access to machining facilities
Finally, because I unfortunately have no better photos or footage of this year's robot in action, here's a video I made of our prototype-bot, which basically served to confirm that a 4WD would be more than enough to drive on the playing field. Special thanks goes to Valve, makers of the beyond-awesome Team Fortress 2, who incidentally own the music accompanying this non-profit, educational-use video.
I decided to try my hand at Widget development recently, and the result was this (here featured next to my favorite widget):
It doesn't do much, besides prove that I can access the command line from a widget and that I have some basic dynamic html skills. To be more precise, it runs "id -un" and "uname -n" and refreshes with a click of the refresh icon. So if you're connected to the internet through some network, it'll show that address instead of the local address (like, guest-wireless.usc.edu).
Anyhow, I'm making it available here. Maybe you'll come across it, and it will be just perfect because you were just thinking of how handy it would be to have a widget like this. Or maybe you'll download it for kicks, and it will prove itself useful beyond your wildest widgety dreams.
When I first got my Macbook Pro, I was not exactly computer savvy, but in the spirit of forwarding that goal I decided that I needed my computer to have a Mac, Windows, and Linux OS. And I wanted native booting, not virtual machines. The process of triple booting on a Mac is not that hard if you know what you are doing, but as I had no idea what I was doing, it took me a while to figure out. I cobbled together numerous tutorials and help pages and I am posting my version here so that others might make use of it.
This isn't exactly something I built, but I think it is in the spirit of 'Building Stuff, Makin' Friends' (though I guess I pretty much decide the spirit of this place anyway). So, without further ado, the tutorial.
A summary first: This tutorial assumes you have a Mac, with the Mac OS already installed. It also assumes no prior partitions on your drive. Furthermore, it assumes that your Windows install CD is exactly that--a SINGLE install CD (you won't be able to eject during the install process because you don't have the drivers for that installed!).
What you will essentially do is this: Install the rEFIt boot Menu, use Mac to make your partitions, install Windows first, install Linux second. The rest is just details.
What you need: Mac install CDs (I have Leopard) Windows install CD (I have XP) Ubuntu (I used 8.10, the 64-bit version. The download is free. Burn it to CD with Disk Utility)
Use the terminal (Applications->Utilities->Terminal) to write partitions. This assumes no previous partitions. (Type the stuff in italics. Be warned! This stuff can be dangerous. If you are not sure of what you're doing, back up your data, and maybe read up on these commands before executing them.)
Disk0s2 should be the Mac volume. I wanted to leave 249 GB to it, and put 17GB aside for Linux and 32 for Windows. The three sizes must add up to less than your total available space on the drive. The command diskutil list will show you the partitions you have set up.
Windows will have to reformat the partition it will be using, otherwise it will install but not boot. I did this to get the installer to give me that option:
That writes over the metadata for that partition, making it Unknown Format to the installer. Alternatively, it seems like you can also just delete and recreate the partition in the Windows Installer instead of using the partition you created with the Mac OS. I prefer the former, though, because I know it worked for me.
Install Windows by putting in the CD and restarting with key C held. After setup, choose the right partition to install to. It will restart a few times, so make sure to boot into Windows to complete the process. After it is done, use the Mac OS install CD to install the drivers for Windows (for older Macbooks it may be necessary to find these drivers in BootCamp and burn them to a CD).
Next, put in the Ubuntu CD and boot it as a live CD. Open up the terminal. Back up the MBR (Master Boot Record). I don't remember if you need to use sudo to get this to work. If permissions are denied, just add it in.
dd if=/dev/sda of=/tmp/sda.mbr bs=512 count=1
Run the installer (it is sitting on the desktop). Choose to partition manually. Select the right partition (sda3 should be it) and press Edit partition. Choose to mount to '/', to format it, and to use ext3. Go to next and ignore the error message about swap. When offered the install summary, look at the advanced options (important!). Install the boot loader on sda3 (your Linux partition) and not on the default (that will make Windows unbootable and none of the fixes I found actually worked without jeopardizing the rest of my systems).
Restore the mbr. I'm not sure exactly when this is supposed to be done but I did it after hitting install and it worked fine. Again, in the terminal:
dd if=/tmp/sda.mbr of=/dev/sda
Wait for the installer to finish. Restart as necessary. Actually, try to shut down instead of restart, because at this point there's a bug that I experienced where restarting freezes my computer on the restart part. Shuts down works fine though, so shut down and press the power button.
Update the MBR by using the Partitioning Tool in rEFIt. When prompted, choose Yes to update. Boot Linux. I had to try booting it twice, but that seems to just be a fluke. I had a lot of those during this process, actually. Make sure all problems are real problems by checking if they happen at least twice.
Finally in Linux open the terminal to make a swap space. Use sudo when permissions are denied.
Now check all your systems to see if they boot properly.
An afterword: who needs that many operating systems anyway? Well, I do. Since installing all three operating systems, I have found that I use them pretty equally. I use Linux for certain robotics and programming projects, Windows for gaming and other programming projects, and Mac just because it works best with this particular machine and also for programming certain things, like Widgets. There are a lot of things I wouldn't have tried if I didn't have the right OS, but now I can run just about anything. And now that I created a 32-bit environment in my Ubuntu for compiling 32-bit code, I can really run just about anything.
It took me much longer than I would have liked, and didn't come out as I initially imagined, and my room is now a mess (and my laundry is still wet, since I forgot to put it in the dryer). Oh well...the creative process can be distracting...
A word about the process: Bass wood and brass tubing, a part from an old hard drive, beads. A bunch of pissed off room- & suite- mates, even though I put away the circle saw at 10:30 when they all went to sleep. I also managed to cut my finger with the regular, manual saw I had to use as a replacement. And, since I insisted on finishing it tonight, I only have seven hours until my first class.
It does sound surprisingly nice for total guesswork though. So I have only few regrets.
