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March 23, 2008

New Tools

It's also worth mentioning with respect to the new piece for Coachella, that I've acquired a few new tools that are making the process much quicker and easier. First and foremost, and really the centerpiece of it all, is the new Tektronix TDS3024B Oscilloscope. This baby has been on my wishlist ever since playing such a huge role in my senior design project success back at UIUC, and with the days counting down fast to Coachella, I decided I needed all the help I could get, and it really has been a big help.

I often describe working on electronics without a good scope as being comparable to trying to work with your eyes closed. It's not necessarily impossible but it increases both the time and frustration of even simple tasks by orders of magnitude. It's much easier to work intuitively when you can see what's happening right before your eyes. The image above, which I grabbed just to confirm that the duty cycle of the PWM was changing (in this design, the duty cycle of the PWM is also capable of changing faster than the eye can perceive), shows in yellow, pink, and green the CS, MOSI, and MISO lines from the FPGA to the SD card, and in cyan one of the channels of PWM out to an LED. Prior to this I had an old Tek265 analog scope which was useful in many circumstances, but for things like the serial bus debugging of the past few days, just didn't do the job. The 3024 has 4 channels @ 200MHz with all sorts of advanced measurement capabilities, FFT, advanced trigger, and a 640x480 color LCD. It also sports its own internal web server so getting screen captures is as simple as opening a web browser. The only negative is that when debugging a 50MHz serial bus on a 200MHz scope, the waves are pretty distorted, so a higher bandwidth wouldn't hurt. I wouldn't trade the advanced features for more bandwidth though, and to up the bandwidth to 500MHz crosses the line into 5-figure territory, which just wasn't in the cards this time. The reality is that the 3024 has been capable of everything I've asked, and I couldn't be more pleased with my decision on this one.

Also very helpful has been the Intronix LA1034 LogicPort USB Logic Analyzer. A logic analyzer is essentially an oscilloscope that trades the ability to see analog voltage levels for the ability to see lots of channels at once — in the case of the LogicPort, 34. It's somewhat limited in its sample storage capacity, which limits the length of data you can view at one time, but it mostly makes up for this with really smart triggering, which lets you focus that limited view on exactly what you want to see. The software also decodes serial buses, so it turns the SPI data and clock wave forms into hex that you can read directly (shown in the image below), which has been invaluable in the past few days. It's also an incredible bargain, when you compare with hardware solutions that (in Tektronix) start at $10k. The LogicPort is no $10k piece of gear, but it's a great addition to the lab that I'm very glad to have made. Plus, it's made in the USA by a small American company doing great work, which is always nice to support when the opportunity arises.

March 10, 2008

Coachella

For the past few months, and really accelerating in the last couple of weeks, Dad and I have been working on a new piece, set to debut at the Coachella Valley Music and Arts Festival April 25-27. At its core will be a much improved spherical display with high-res surface complemented by volumetric accents, all in 24-bit color. On-board will be on the order of 10GB of removable flash memory, combining the increased resolution and color depth with a much greater potential show length as well as much easier program changes. All of this will lend itself toward a renewed focus on content, which is a very exciting thing for me as a big step toward the high-definition three-dimensional canvas which I originally envisioned with the ORB.

To make this a reality, I've finally crossed the void into the world of FPGA, and I'm loving it. The ability to quickly create massively parallel hardware in a few lines of code is really powerful. It takes a bit of getting used to, but within a few days I was generating the beginnings of working code in VHDL, largely with the help of Volnei A. Pedroni's Circuit Design with VHDL and the Altera Cyclone III Starter Kit. Now, just under a week into serious development, I feel as though I've got a pretty good handle on things, so the learning curve isn't as steep as it initially seemed, particularly if you've got some crossover experience developing both software and hardware.

As is unfortunately too often the case though, the learning curve seemed steeper when it came to using some of the pre-existing libraries I found. I needed SPI to access the flash memory, and so I started looking for libraries. The Altera board shipped with Quartus II which I'm using for all of my development and is a pretty nice package. Quartus leads you directly to Altera's NIOS soft-core processors with all kinds of great add on modules. These designs are cool because they allow you to set up part of the FPGA to act as a microprocessor meaning you can develop in a typical procedural language like C where appropriate, using the hardware definition languages only where necessary. The demos were easy to walk through and I thought I had everything figured out — until I read about the $2500 per seat licensing fee.

I'd heard of OpenCores and it sounded like a really cool project so I thought I'd check it out. OpenCores is essentially Sourceforge for HDL (hardware definition language) designs, albeit much less trafficked. It appears that there is some great work going on there, but at my level of knowledge, the documentation was just insufficient for my needs. If I really needed a fully-featured CPU running on my chip I'm sure I could have figured it out given enough time, but as it stands it's far from plug and play. And as the countdown timer on coachella.com continually reminds me, the show starts in 45 days, 17 hours, 28 minutes and 26 seconds. So it's time for action.

As it turned out, I spent a bit more time tweaking the SPI module I had been writing prior to looking at the soft cores, and with just a bit more effort, got it up and running. I then began work on a state machine that controls the SPI module and passes the data out to a set of PWM modules which actually control the LEDs. I'm still working on scaling the code and getting some of the finer control functionality implemented, but all indications are that with a few more days of work the code will be 99% complete. Then its on to PCB design, construction, and content.

In parallel with the electronics, Dad's hard at work building two chassis, one to ship to Manhattan for me to use as a framework to finish the electronic development and another to finish out in time for Coachella. We've got a totally new look this time, a bit more design-influenced and incorporating some cool high-tech materials. I'll get some photos of that part of the process up here as soon as they become available.

In the meantime, it's back to work.

August 17, 2007

Material Connexion

Thanks to everyone who came out tonight to the closing party of the Interactive Youth exhibition at Material Connexion. I'd also like to thank everyone at Material Connexion, who hosted a great event, especially the outstanding Ben Rosenthal, Project Manager for Public Programs.

Also, in from the archives is a link from back in May from the Popular Science How 2.0 Blog about the ORB at Maker Faire.

July 11, 2007

Material Connexion: Interactive Youth

Material Connexion, New York has installed an exhibition entitled Interactive Youth which is an assortment of work from Michael DelGaudio, Anne Hong, Andrew Schneider, and my father and me, including Storyteller, Sasu Bracelets and Ochie's Cube, Solar Bikini, The Alphabet Machine, Mutherboards, City Streets, Northern Lights, and The ORB.

The exhibition was just blogged by the industrial design site Core77, and yesterday I took some photos, a few of which are posted below.



The exhibition will be on display through Aug. 3, 2007. Material Connexion is located at 127 W. 25th St., NYC. Many thanks to Ben Rosenthal @ MC for all of his hard work in making this exhibition a reality.

June 12, 2007

Technology on your time

Bringing the Maker Faire home:

Thanks once more to the entire Maker Faire team for a great time (and the banner).

In related news, according to the official site, Jimmy Kimmel Live! will be airing the Maker Faire segment on Wednesday, June 13. Watch for the makers!

May 19, 2007

The ghost of Jimmy Kimmel...

...on the ORB!

Jimmy and his team were great. We shot a short interview which should air on Jimmy Kimmel Live! within the next couple of weeks. Jimmy said he "felt like the Mona Lisa" and that his mug on the ORB was "the most beautiful thing I've ever seen". MAKE!

May 14, 2007

En route.

This comes to you from a quiet hotel lounge on the east side of Denver on our way to the MAKE Magazine Maker Faire, where we will join some 400 makers (including a handful of ITP'ers such as Andrew Schneider, Team Botanicalls, Giana Gonzalez, Tom Igoe, and last but not least, FabInfo instructors Toru Hasegawa and Mark Collins) with ORB and ultraORB in hand and ready to exhibit. A few tens of thousands of attendees are expected of all ages and all walks of life and I'm expecting a fantastic time sharing our work with the curious as well as exploring the rest of the exhibits. I'm also slated to give a talk/demo on Thursday's Maker Day, a day of events held specifically for the exhibitors and other presenters and organizers.

Maker Faire is held at the San Mateo Fairgrounds in San Mateo California and is open to the public on May 19-20. Advance tickets are $15 for adults, $10 for students 21 and under, and $5 for children 12 and under ($20/$15/$5 respectively on-site). Hope to see you there.

May 8, 2007

One final ITP all nighter

Just for old times' sake...

May 6, 2007

ultraORB Thesis Presentation

The presentation of the ultraORB at ITP Thesis week is now online and can be streamed here or downloaded here. I'm working now to improve the programming, moving toward displaying controlled geometric objects Tuesday and Wednesday at the ITP Spring Show.

May 3, 2007

Double spin (1/2).

Moving forward — a quick spin with one of the two boards. Now on to connect the brushes to power up the other half. More later...

May 2, 2007

Goodnight

The initial mockup. Time for bed.

May 1, 2007

Lights.

LEDs are soldered and testing is underway. There are a few minor bugs to tweak out with the lighting and then it's on to full assembly and programming. The color balance is a bit askew, but that's an issue for another day. 48 hours to go...

April 30, 2007

12.5%

Here's a view of 1/8th of the final assembly with LEDs in place. 280 LEDs to go.

Resting atop the PCB is the CNC machined aluminum board mount, holding in the foreground one of the four DC-DC stepdown converters from short-circuit.com. The board mount is topped by the three conductor commutator assembly, handmade from readily available materials and a few custom laser cut plexiglas spacers. The commutator mates with a set of brushes to deliver +15VDC, GND, and a timing signal from one of a pair of hall effect sensors mounted on the assembly rotating about the vertical axis (each quadrant of each PCB also has its own hall effect sensors to sense rotation about the horizontal axis).

April 29, 2007

ultraORB Concept Video

For those of you who haven't been following along with the in-person presentations, here's a little clip of video that was shot about a month and a half ago, showing the ultraORB concept in action. This is a demo and concept test with 4 single-color LEDs — the version due to be presented this coming week will have a total of 320 tri-color LEDs under microprocessor control to create a truly three dimensional persistence of vision display.

The final one hundred hours

Just under 100 hours to go until the first display of the ultraORB at my thesis presentation, Thursday, May 3 at 8:40pm. There is still a lot to do, but things are moving forward. 16 microcontrollers are interfacing with 128MB of onboard flash memory and my laptop through 8 dual-channel USB interfaces. Now it's on to wrapping up a few loose ends and then soldering the 320 RGB LEDs. Then on to the first spin. Stay tuned...

April 15, 2007

The view from the solder station

After a couple of days of intense soldering, the first major task is complete. The 960 0201 LEDs are all in place. It's funny, after two days of work, the boards look almost entirely the same to the naked eye. While I can barely focus on the screen to write this (seriously — now I understand what it's like to need glasses, if thankfully temporarily), the upside is that after soldering almost 1k 0201 parts, the 0402 package parts look like bricks and are easier than ever to handle. In any case, I'm here to say that it is very possible to hand solder 0201 parts. Time to go clear the head and get ready for another day of soldering tomorrow. In the meantime, here's the view from the soldering station:

April 12, 2007

Wuhan Direct

The circuit boards are here, having made the trip from the GoldPhoenix fab in Wuhan, China to Manhattan in about 36 hours. The parts are here, a day early in typical DigiKey fashion. Now it's time to start burning some flux. Before I do, though, here are a couple of quick photos from the unpacking process.


The virgin board. I have a pair of these to solder, with at a guess maybe 3-4k SMD pads each. It looks like I won't be seeing much daylight for the next week or two.


If you've ever wondered what $2k in DigiKey parts looks like, wonder no more. Not all that impressive on the surface, eh?

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