When [hkdcsf] was a teenager, he made a Christmas star with an up counter driving decoder logic and using transistors to light LEDs in festive patterns. He’s revisited this project using modern techniques including a microcontroller, a DC/DC converter, and constant current LED drivers.
The project uses two AA batteries, and that’s what makes the DC/DC converter necessary. Blue LEDs have a forward voltage of just over 3V, and the LED driver chip requires about 0.6V of overhead. Two fresh AAs will run a tad above 3V, but as they discharge, or if he’s using rechargeables, there just won’t be enough potential. To make sure the star works even with whatever LEDs are chosen, the converter takes the nominal 3V from the batteries and converts it to 3.71V.
Continue reading “Christmas Star uses Two AA Batteries”
It’s August, and of course that means that it’s time for retail stores to put up their Christmas decorations! But seriously, if you’re going to do better than the neighbors you need to start now. [Joey] already has his early start on the decorations, with a house-sized light show using LED strips and a laser projector that he built last Christmas.
What started off as a thought that it would be nice to hang a wreath over the garage soon turned into a laser projector that shows holiday-themed animations on the front of the house. The project also includes a few RGB LED strips which can match the colors displayed by the projector. The LEDs are powered from a custom-built supply that is controlled by a laptop, and the program that runs on the computer averages the colors from the video signal going to the projector which lights up the LED strips to match the projected image. This creates an interesting effect similar to some projects that feature home theater ambient lighting.
The only major problem [Joey] came across was having to account for the lasers’ motion in the projected patterns, which was causing the computer to read false values. This and a few other laser-related quirks were taken care of with a bit of programming to make sure the system was functioning properly. After that it was a simple matter of attaching the projector to the roof and zip-tying the LED strips to the eaves of the house.
The projector is weatherproof, has survived one harsh winter already, and can be up and running for any holiday. With Halloween right around the corner, this could be a great way to spice up some trick-or-treating. Check out the video after the break to see this setup in action.
Continue reading “Laser Projected Christmas Lights”
Reader [pscmpf] really digs the scrolling light look of old marquee signs and as soon as he saw some Christmas lights with G40 bulbs, he was on his way to creating his own vintage-look marquee arrow.
We must agree that those bulbs really do look like old marquee lights or small vanity globes. [pscmpf] started by building, varnishing, and distressing the wooden box to display the lights and house the electronics. He controls the lights with an Arduino Pro and an SSR controller board. The 24 lights are divided into ten sections; each of these has its own solid-state relay circuit built around an MC3042 as the opto-coupler, with a power supply he made from a scrap transformer.
[pscmpf] shares some but not all of his code as it is pretty long. There are five patterns that each play at three different speeds in addition to a continuous ‘on’ state. In his demonstration video after the jump, he runs through all the patterns using a momentary switch. This hack proves that Arduino-controlled Christmas lights are awesome year-round.
Continue reading “Arduino-Controlled Marquee Arrow Points the Way to Whatever You Like”
[James] was wandering around Walgreens after Christmas and found something very interesting – RGB LED Christmas lights that were individually addressable. At $6.50 for a strand of 15 lights, he just had to buy a few and figure out the control protocol. After all, who can turn down a big, cheap, controllable RGB LED strip?
The packaging for these lights – apparently manufactured by BriteStar – includes a ‘try me’ button that cycles through different light patterns. This button is what initially tipped [James] off to the fact the lights on this strand could be individually controllable. Opening up one of the lights, he found exactly what he wanted: an epoxy blob, two wires for power, and three wires for the signaling.
After checking out this light with a scope and logic analyzer, [James] realized there was a very, very simple protocol going on. Essentially, the entire string functioned as a gigantic shift register, taking the values for one light and pushing it down the string. In looking at the protocol, [James] also discovered] these lights support 16 levels of brightness. Yep, RGB LED Christmas Lights with PWM for under $7. Can’t beat that.
[James] wrote an Arduino library to control these strings and put it up on Github. While your local Walgreens has probably already hidden these lights away in the back of the store, it might be worth asking around to see if they have any left.
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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As [Medhi] was setting up his Christmas tree, he found a string with a few broken lights. Because he’d bought a cheap string of lights wired in series, of course one bulb was burnt out, rendering the entire string useless. His original game plan was to search through the entire strand for the broken bulb, but that’s the easy way out. His backup plan was to zap the broken bulb out of the string. After a few hours of figuring out what that meant, he came up with a way to fix a broken string of lights.
When a bulb burns out, the filament breaks creating an
air argon gap between the two electrodes. By sending a huge voltage down the string, it should fire an arc through that gap, illuminating the burnt-out bulb for a brief time.
Experiments with socks and low humidity commenced, but it wasn’t until [Medhi] stuck his finger in a lighter that he found a better source of high voltage sparks. [Mr. Brows] connected the piezoelectric element to the plugs on his string of lights and… nothing happened. At least until he plugged the lights back in. Then, strangely, they worked. The reddit thread for the video says this behavior is due to an anti-fuse built into the bulb. When enough voltage goes through this anti-fuse, a thin sheet of insulator breaks down and allows dead bulbs to short themselves.
Hackaday head honcho [Mike] just got this method of finding dead Christmas lights to work, replacing 14 bulbs in a string of 100 lights. This leads us to an interesting question: why isn’t this simple method of fixing a string of Christmas lights common knowledge? You would think something this useful wouldn’t be introduced to the world via a YouTube video where someone repeatedly burns and shocks himself. You can, of course, buy something that does the same thing, but this is far too simple of a solution for a classic problem to pass under our noses for this long.
Continue reading “Fixing Christmas Lights And Shocking Yourself Silly”
Here’s a cool hack to get you in the December holiday mood! Arduino controlled Christmas lights!
It all started because [Anx2k] had some leftover LED’s from one of his other projects, so he decided to make use of them as permanently mounted Christmas lights. He’s installed them underneath his tiled roof, and run all the wires into his attic where he has an electrical box serving as the main control hub. He uses an Arduino Uno to control them, and a 460W computer power supply to provide the juice. The LED modules themselves are Adafruit RGB pixel strings. There’s actually three of the LED modules per tile — two shining up to illuminate the tile, and one shining out.
He’s set up a ton of different patterns to run, and they are pretty awesome! Check out the video after the break.
Continue reading “Arduino Christmas Lights”