April 25, 2008

AVI ‘08

Filed under: Life, Mac, Technical — Joey @ 2:54 pm

I’m headed to Advanced Visual Interfaces ‘08 this summer in Naples, Italy to present the work Josh and I did on VCode + VData regarding video coding tools. I’m really proud, as it’s my first first-author!

You can download VCode and get more info about it on the Social website.

Enjoy!

VCode Main Window

April 19, 2008

Blu-Ray Laser Pointer

Filed under: Electronics, Laserist, Technical — Joey @ 10:46 pm

I was sitting in the basement of the Siebel Center one day when Matt Sparks mentioned the Blu-Ray Laser Phaser project, made possible by the Sony Blu-Ray replacement drive assembly for the PS3. I impulsively purchased one such module on eBay and set out to build the best possible Blu-Ray Laser Pointer.

IMG_4392.JPG


Home-built Blu-Ray Laser Pointer

I focused on building a high quality device. I am really happy with the size and quality of the case, and current-limited power supply, as opposed to the simple resistor based design some other designs suggest. I also opted for rechargeable Li-Ion batteries for great performance and size. This necessitated the installation of a charging jack on the back of the pointer as well.

Parts:

  • Sony KES-400a replacement Blu-Ray drive module for PlayStation 3
  • Pomona Electronics Size “B” Die Cast Aluminum Box with Cover, Baked Blue Enamel finish, Model# 2417
    as seen on page 53 of their catalog. All of their other products are great too. Highly Recommended.
  • 650nm 5mw 12X30mm laser module from Aixiz. This company, on the other hand, is as sketchy as you get, but I’ve always had great services, so, if you need cheap lasers, it works.
  • (2) AAA Li-Ion cells with solder tabs.
  • Protection Circuit Module for Li-Ion cells.

You’ll need some other items as well, such as a jack for charging the device, wires, a breadboard PCB, and various components for the power supply. You can pick those out from the schematic below though.

There’s lots of great info regarding the Blu-Ray diode on a page at Sam’s Laser FAQ. This was the source of the power supply circuit, and information about the amount of current that could be run through the diode. Unfortunately, the construction quality of the power supply isn’t the greatest, and I find the case design for the pointer at the bottom rather wasteful. The circuit is, however, of sound design.

It is only somewhat difficult to fit the power supply on to a suitably small breadboard to fit in the case. I think a smaller package version of the LM317 would be better suited than the TO-220 packaged one I chose.

IMG_0116.JPG
IMG_4379.JPG


All parts ready for assembly / Power Supply


IMG_4394.JPG
IMG_4396.JPG


Aperture / Operational

More pictures in the Album.

The experience using the Blu-Ray laser pointer is rather interesting. It is clearly extremely bright, and for this reason I must underscore the importance of being extremely careful to avoid eye exposure. However bright it is, sometimes it appears quite dim because the color is very near UV and normally much more deep violet than it appears in the photo above. On paper and bleached targets it does appear very blue, or even white on orange fluorescent surfaces. Occasionally there is even some eye-strain associated with looking at the beam incident on a light colored surface.

In a completely dark room it is even possible to see the beam in air, which is rather interesting, because the dot appears less bright than a cheap 5mw red laser pointer might in a well-lit room. I don’t have the appropriate equipment to properly measure light output, but I have chosen not to run it at maximum current in order to prolong diode life. It is plenty bright at it’s current level of ~30-40ma.

Soon I hope to label the box with appropriate warnings and specifications for the charging port on the back, but I need to prepare appropriate stencils for painting first. I think it is built such that I can expect many years of service before needing to service it.

I’d love to hear if you’re building one or have any questions about mine.

April 16, 2008

YouTube in MP4 via QuickTime Plugin!

Filed under: Technical, Web — Joey @ 4:09 pm

Today I saw this link on Daring Fireball that presents a bookmarklet to add a link to the YouTube page to download a (higher quality) MP4 version of the video you’re viewing. This is great, but I dislike flash in general, so I’d rather not even watch the embedded version to begin with. I’ve crafted the following bookmarklet to replace the existing flash player with an embedded QuickTime player for the MP4 file. Go try it out on YouTube.

To install the bookmarklet, simply drag it to your Bookmarks Bar (in Firefox, Safari):



This has only been tested on a Mac. I expect it won’t work on some other OSes because it uses the <embed> tag rather than the <object> tag. I encourage someone fix up this bookmarklet to work on other platforms by using the <object> tag, and condense it a little–because it is rather long. I’d be happy to post an updated version if someone improves it. Additionally, a GreaseKit script would be great too.

Enjoy!

Update:
Seems to work in Firefox on Windows.

Update:
Comment from Kris below provides a Greasemonkey/GreaseKit Userscript.
Userscript

February 29, 2008

Nuage Vert is Live!

Filed under: Creative, Laserist, Technical — Joey @ 12:28 am

There are some really great photos up now at http://www.nuagevert.org please go check it out!

February 12, 2008

PS3 Blu-Ray Laser Diode

Filed under: Electronics, Laserist, Technical — Joey @ 2:02 am

As if I didn’t already have enough going on this week, I just did this:

PS3 Diode Laser

Parts were approximately $60, using the PS3 replacement drive assembly and other recommended items from various how-tos on the Internet. Essentially, the diode is removed from the disc assembly, installed in an old 5mw red laser housing, and connected to a brand new LM317 based power supply. I am well on my way to building an adorable little blue laser pointer for far under $100. It is really more purple than blue, but it looks pretty cool. Right now I’m still too afraid to crank up the juice to see how bright it can get.

According to some random forum post:

lasing threshold: 27-28ma
working current/voltage: 4.4v @ 30-40ma
output:
30mA 2.68mW
35mA 9.45mW
40mA 13.3mw
45mA 17.0mW

I can at least verify the lasing threshold was accurate–I do not have the appropriate equipment to measure power output.

And of course, I couldn’t have done it without information from Sam’s Laser FAQ, specifically the article examining Blu-Ray Laser Diodes.

January 23, 2008

Nuage Vert

Filed under: Creative, Electronics, Laserist, Mac, Technical — Joey @ 4:55 pm

Last fall I was contacted by Heiko Hansen (of HeHe) regarding using the EasyLase USB on the Mac. I must say I was quite intrigued when I found out that he was working on Nuage Vert, a visualization of energy usage in Helsinki. The project uses the cloud of emissions from the Salmisaari power plant as a canvas to demonstrate how much energy is in use by the city.




photo credit HeHe

The project is going on display February 22-29 in Helsinki. I encourage you to go check it out more in depth at www.nuagevert.org.

For the project, I ended up creating a Java wrapper for the libEasyLase driver for OS X. It is now possible to get laser output on the EasyLase USB from inside a Java app on the Mac. Please contact me if you’re interested using this.

December 26, 2007

End of Semester Post

Filed under: Life, Technical — Joey @ 11:13 pm

So, perhaps you were confused by the last post. If so, I apologize. Finals are a busy time, so there wasn’t much time to explain–this is also why there’s been a break in posting. The link was a blog that was setup during the very intensive finals studying. We commandeered a conference room for a week straight. We even did some original research while in there.

Unary Red-Black Tree

After finals is when the fun really began though.

Coffee Joy
Winter Wonderland


Coffee on a snowy night with Erik

Wall Coated in Ice
Snowmen


An icy wall and adorable snowmen outside the Siebel Center

The snowy and icy days were a fun cap to the end of the semester and signaled a start to winter.

iPhone Box


Then iPhone came and changed my life

But getting my iPhone was simply fantastic. I can’t wait to start writing apps.

December 4, 2007

The USPTO website is horrible

Filed under: Mac, Technical, Web — Joey @ 11:00 pm

And my web browser of choice is Safari 3.0 for Leopard. Unfortunately this makes viewing TIFF images of the Patent Office’s website an absolutely abysmal experience.

So today in CS421 I found GreaseKit, a Safari Plugin that allows one to run Greasemonkey-like scripts on web pages in Safari. So I wrote a userscript: usptofix.user.js to change the <embed> tag to the <img> tag, resulting in success.

originalSite
modifiedSite

(original left, modified right)

I simply scale the TIFF to the page width, and everything is okay.

Unfortunately, it crashes Safari half of the time I load this page; I’ve reported a bug against GreaseKit.

It is probably better to just use Google Patents, but at least I learned something.

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