Sunday, January 27, 2013

Disneyland and infrared communication

Last year, Disney unveiled new LED-enabled Mickey Mouse hats that interact with Disney California Adventure shows like World of Color, a feature they call Glow With the Show. Disney Creative Entertainment Technical Director, Chuck Davis explains in the video below.  p.s. Doesn't he seem to have the coolest job ever??

This video above was taken during a special closed viewing of the show for annual passholders to test out the hats, which they handed out for free. LUCKY!

The hats actually have a simple circuit inside, which you can read about in a teardown at the blog Stuff Andy Makes. Excuse me while I geek out a little about the components in this thing. There is a battery, switch, and a small Texas Instruments microcontroller which acts as the brain. Each ear is equipped with two RGB LEDs which can individually emit red, green or blue, or any combination of those three colors, including white.

Side-note: The RGB LED is actually just three individual LEDs packed into one package.  Here's a similar surface mount RGB LED in a 3.5 mm × 2.8 mm package with four pins: one for red, blue, green, and a common pin which can either be a common anode or cathode. Isn't it cute? You can see the little wire bonds connect to the common pin at the top right quadrant.

Four pin surface mount LED package, with three individual LEDs and a common pin.

The interesting aspect of the hats isn't so much the LEDs, it's the data synchronization. The hats 'interact' with shows in the park depending on where you're standing. Sounds magical, but it's actually possible through simple short-range IR communication, or in other words, at slightly longer wavelengths than visible by the human eye.

Note the x-axis is log scale here.  Most consumer IR products operate at wavelengths around 900 - 950 nm.

For the World of Color shows, the audience viewing area is divided into 40 different zones, and IR transmitters located throughout (on speaker towers perhaps) that transmit different data signals. The signals are 'seen' by an IR receiver located in one of the ears of the hat. As Chuck explained above, it's the same way remote controls wirelessly transmit information to your TV. There may be some position triangulation using signal strengths of neighboring transmitters as well, but that's pure speculation.

IR transmitters are not new technology, they're often just a GaAs-based LED plus some lenses to control the transmission angle. Sometimes it's a laser diode. The receiver is a photodiode, which is basically an LED operated in reverse: shine a light at it, it generates a current, like solar cells. Here's a tiny surface mount IR receiver similar to the one in the LED hat, by Vishay.

You can buy reels of these tiny IR receivers at less than $0.60 a pop.

IR wavelengths fall just outside the visible spectrum so you can't see them, but the 'light' emitted from IR transmitters otherwise has the same properties of visible light. One of these properties or requirements is line-of-sight (LOS), meaning: if you're wearing an LED Mickey hat and you're standing behind a tree or your head is turned the wrong direction, your hat may not 'see' or 'receive' the transmitted signal. Line-of-sight of IR components are demonstrated nicely in this Youtube video.

Fun fact: Plenty of wireless communications, such as radio, also depend on line-of-sight which is why radio towers and repeaters are often placed on top of mountains.

Little dudes demonstrating Line-of-Sight with a radio transmitter/repeater 

Another fun fact: Fluorescent lighting (including compact fluorescents) can emit spurious light in the IR spectrum, and early adopters found their lightbulbs interfered with IR communications of their TV remotes, causing channels and volume to change spontaneously. The problem was eventually solved by altering the operating frequencies of the respective components, however, the simplest solution is to just move or shade the lamps to remove the line-of-sight.

According to Stuff Andy Makes, you CAN get the Disney LED hats to respond to your TV remote control, but doesn't say what it makes the ears do. Doesn't that make you want to get one and try??

Disney's Glow With The Show LED hats also have a tiny IR transmitters (just an IR LED) inside them in addition to the IR receiver. This feature allows you to synchronize the two hats only by bringing them in close proximity, as demonstrated by Erin of the Disney Parks blog. Neat, huh?

The Glow With The Show hats normally cost around $20 and are sold in some gift shops around Disneyland California Adventure. I'll be interested to see how Disney Imagineers integrate Glow With The Show features throughout the rest of the park. Actually, I had every intention of buying one when I was at Disneyland last weekend, but honestly I thought they're pretty ugly on their own... so I went with some Minnie Mouse ears instead. :P

Friday, January 25, 2013

Complex concepts with very simple vocabulary

The UpGoer5 meme has gone around the Twitter and science blogs lately, so I tried my hand at describing my LED and laser diode research using the 1000 most commonly used words

When something is really, really small --too small to even see-- it acts in very strange ways. This is my work. I study really, really small things and get them to light up. This is a totally new way to make light. My lights are smaller, last longer, and don't get hot when you use them, so we can do many interesting things that we couldn't do with the old way of making light. For my job, not only must I understand how these very small things work and get them to light up, I also need to understand how our eyes see, and then I try lots of different things to make the light better and brighter. I hope that one day, the lights I work on will be used all over the world and am excited to see that start to happen.

It's an interesting exercise that reminds me a lot of trying to come up with an elevator pitch of my research project.  Because the vocabulary is so limited, I felt my description had to get really vague and big picture. For example, I could not come up with a way to describe a laser diode without using words like 'narrow' or even 'shape' or 'beam,' which were not included in the list, so I went with really generic description of solid state lighting "a new way to make light."

The UpGoer5 text editor by Theo Sanderson was inspired by this XKCD comic by Randall Munroe.

Check out Ten Hundred Words of Science for many more descriptions of research science using simple words.

Thursday, January 10, 2013

Overly Honest Methods

I'm so happy to see the hilarious #OverlyHonestMethods Twitter hashtag has gone viral, as evidenced by recent coverage by Huffington PostThe TelegraphScientific Americanio9, and Boing Boing.

Newsy Science points out the potential "troubling" side of being overly honest...

I understand the potential for controversy when questionable scientific practices verge on the side of being deceptive or otherwise demonstrate a lack of integrity. Yet I think more good than bad can come out of airing out some of the silly and honest aspects, albeit sarcastically, about how real science is done. If anything, it reminds us that scientists are humans too.  It's comforting to know that we all get lazy, take shortcuts or unintentionally make mistakes sometimes.

A perfect experiment is an impossibility, and part of being a good scientist and researcher is knowing how to identify and avoid, or at least acknowledge, all the messy complications and difficulties that come with experimental work.

Sunday, January 6, 2013

The importance of asking for help

The moment will be burned in my brain forever. It was like an anxiety dream come true. I was in third grade, my teacher just handed out an exam, and I was lost. I didn't understand the directions or how to even begin to answer. All the kids around me were working away, writing down answers while I just sat there staring at the blank page, completely frozen. I felt so helpless. I even whispered to the kid next to me if I could see his answers to which he hissed: "NO! THAT'S CHEATING!"  I started to cry.

Desperate, I stood up in the middle of the exam, tears still streaming down my face, and walked up to my teacher sitting quietly at her desk and asked for her help. She was actually very receptive to this and kindly reminded me what the exam was about and how I might answer. Whatever she said made it click. By the time I got to my desk, my tears had stopped. Perhaps I was even smiling. I had this under control. I GOT THIS.

There's value in admitting you don't know something. I think back over my grad school career and some of my biggest regrets are not asking for help sooner because I didn't want to let on that I was struggling or incapable. I wasted a lot of time being afraid of looking stupid and then feeling guilty about it. Is it arrogance? Impostor syndrome? Either way, it's so self-defeating.

Some of my tips for grad school include things like "prepare to feel stupid (again)" and fostering an environment that allows you to be productive as possible. Sometimes your ego is the only thing holding you back from being productive. 

The thing about scientific research is it will always seem full of more questions than answers. At the PhD level, everyone is so specialized that there's bound to be someone who knows more than you do about some particular aspect of your research project. Being a productive researcher involves knowing who to talk to in order to make progress. Don't think of it as an admission of personal failure, think of it as a collaboration. Often others are more than happy to help, and in fact, studies have even shown that most people underestimate how many people are willing to help even a perfect stranger.

It's a lesson I keep reminding myself. This past year, I kept putting off some measurements because it required being trained on an intimidating piece of lab equipment. It came down to me being afraid of asking for help from the tool manager who has a reputation of not returning emails or being particularly friendly. I finally got fed up with myself, asked for his help in person, and found he was more than willing to do so. Once I got through that first measurement I felt comfortable using the equipment on my own. Then I wondered, what on earth took me so long?

Friday, January 4, 2013

Dara O'Briain and Science Club

There are two things I love for sure: comedy and science. It's rare the two intersect, but when they do, amazing things happen.

Dara O'Briain studied mathematics and theoretical physics at University College of Dublin before embarking on a career in comedy.  I love this rant on the public perception of math and science and anti-science in the media, from his comedy special Talks Funny.

"Science knows it doesn't know everything, otherwise it would stop."

Dara currently hosts a television show Dara O Briain's Science Club on BBC Two. Each episode explores a different scientific topic in an informative, accessible, and humorous way.  I love it. I wish there were more shows like this on American television.

Episode 1 investigates human reproduction and genetics. I loved the bit about the invention of bicycles and personal transportation helping diversify the human gene pool.

More episodes may be available on Youtube, unless you're lucky enough to live in the UK and watch it on BBC.