Christmas Tree Analyzes Your Tweets

It’s Christmas time. You have a string of 50 individually addressable RGB LEDs, what would you do? Well, [Barney] decided to try something different. He’s made a Christmas tree that reflects Twitter’s current sentiments about the holiday.

Wait, what? We admit, it’s a kind of weird concept, but the software behind it is pretty cool. As it turns out Stanford University’s Natural Language Processing Group released the source code for their sentiment analyzer. Unlike a normal sentiment analyzer which assigns points to positive words and negative points for negative words, this one actually uses a deep learning model which builds up a representation of entire sentences based on their structure — only problem? It was designed and trained to analyze movie reviews, not Christmas tweets.

Regardless, it still does the trick (kind of), but, it’s pretty slow. [Barney] has his fastest computer running four instances of the analyzer, which pulls Christmas tweets that have been sorted by the Twitter API — it then analyzes them, assigns the sentiment, and places them in a second queue. He’s using beanstalkd for the queuing and a Raspberry Pi to control the lights. The result is a pretty light display whose colors represent the sentiments of incoming tweets — it’s hard to say if it’s actually successful in reflecting the opinion of the tweets, but it’s a pretty cool concept.

Stick around after the break to see the Christmas Tweet Analyzing Tree in action — say that 5 times fast!

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Hacking a Christmas Tree for Less Blinkyness

What good is a fiber optic self-lighting Christmas tree if it flashes so fast it will put you into an epileptic attack? The answer is “Not very good”, if you ask [Mads Nielsen] a.k.a [EcProjects]. So [EcProjects ] started a little project to slow the Christmas tree’s blinkyness down to a more reasonable rate. The task didn’t seem too difficult at first but turned into a quality tutorial building a variable frequency H-bridge motor control.

After opening the base of the tree [EcProjects] found a 12 volt AC geared synchronous motor turning a multi colored translucent plastic disk. A bright spotlight was shining upwards through the turning disk into the ends of hundreds of small fiber optics. This mechanism dumps loads of multi colored light out the ends of the fibers at the tips of the Christmas tree branches as the disk turns.

His goal was to slow down the motor; however, the rotation was based on the 50 Hz mains signal. In order to continue using this motor a lower frequency AC power source was needed. What follows in the video is an excellent lesson on how an AC synchronous motor works plus how to build a variable frequency control and H-bridge using some transistors, resistors and CMOS 4069 inverter chip.

In the end the frequency drive could only be lowered to about 30 Hz before the synchronous motor would stall and reverse using his design. [EcProjects] was bold enough to include several fails which always provides more opportunity for learning and is greatly appreciated.

If you believe you have a better solution please share your idea in the comments. I’m sure the first proposal will include an Arduino and servo modified for continuous rotation, but any solutions would be fascinating including modifications to his design. You can join us after the break to watch the video.

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Mega Tree Game Display

Christmas may be over, but the holiday hacks keep rolling in, like this awesome interactive Mega Tree Game Display! [Lior] loves setting up light shows every year (just check out last year’s awesome White Christmas display with music!), but taking them down just… well… sucks! So this year he decided to make a fully controllable non-holiday specific light display that he can reuse it all year long.

It features 12 x 5 meter long waterproof RGB LED strips secured firmly to the front of his house, making a trapezoidal 12 x 150 pixel display. It was originally controlled with an Arduino but he found the USB connection was far too slow for the high frame rates he was aiming for — so he’s using a combination of a Raspberry Pi and a Teensy 2.0 instead.

Now, just making a programmable light show suitable for all holidays is pretty cool we must admit, but as [Lior] puts it, a plain light show is “so last decade”. So he’s gone and made the whole thing smartphone interactive. Yep, you can actually log in with your phone and play a silly game that involves dropping gifts on houses and snowmen. He’s also got a pretty cool Hanukkah display that features a spinning dreidel! Check out the full demonstration video after the break.

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