Yes, [Heliox] has built a Valentine’s day project, and the presentation is top notch as always. A heart is 3D printed in white filament, with two chambers separated by a thick wall. Each chamber features five NeoPixel LEDs, controlled by an ESP8266 in the base. The color of each chamber can be controlled through the Blynk smartphone app, allowing you to choose the exact colors that best represent your relationship.
The 3D printed heart does a good job of diffusing the LEDs, with the device showing a rich and consistent glow without any unattractive hotspots. It’s a fun holiday build, and if you’re quick, you might just have time to print one yourself if you start right away.
Listen, it hurts to hear, but somebody needs to say it. It’s over, OK? You’ve got to admit it and move on. Sure, you could get away with it for a week or two in January, but now it’s just getting weird. No matter how hard you fight it, the facts are the facts: the holidays are over. It’s time to pack up all those lights and decorations before the neighbors really start talking.
But don’t worry, because there’s an upside. Retailers are now gearing up for their next big selling season, which means right now clearance racks the world over are likely to be playing home to holiday lights and decor. That wouldn’t have been very interesting to the average hacker or maker a few years ago, after all, there’s only so much you can do with a string of twinkle lights. But today, holiday decorations are dripping with the sort of high-tech features you’d expect from gadgets that are actively aiming to be obsolete within the next ten months or so.
Case in point, the “AppLights Personalized Projection” which I found sulking around the clearance section of the Home Depot a couple weeks back. This device advertises the ability to project multi-color custom messages and animations on your wall, and is configured over Bluetooth with a companion application on your Android or iOS device. At a minimum we can assume the device must contain a fairly powerful RGB LED, an LCD to shine the light through, and some sort of Bluetooth-compatible microcontroller. For $20 USD, I thought it was worth taking a shot on.
Around this time last year, the regular Hackaday reader may recall I did a teardown for a Christmas laser projector. Inside we found red, green, and blue lasers of considerable power, as well as all the optics and support hardware to get them running. It was a veritable laser playground for $14. Let’s see if the AppLights projector turns out to be a similar electronic cornucopia, and whether or not we’ve got a new Hackaday Holiday tradition on our hands.
Printing customized Christmas cards is a trivial matter today: choose a photo, apply a stock background or border, add the desired text, and click a few buttons. Your colorful cards arrive in a few days. It may be the easiest way, but it’s definitely no where near as cool as the process [linotype] used this season. (Editor’s note: skip the Imgur link and go straight for the source!)
The first task was to create some large type for the year. [linotype] laser printed “2018” then used an iron to transfer toner to the end of a piece of scrap maple flooring. Carving the numbers in relief yielded ready-to-go type, since the ironing process took care of the necessary mirroring step. The wood block was then cut to “type high” (0.918 inches; who knew?) using a compositor’s table saw – with scales graduated in picas, of course.
The month or so after the holidays have always been a great time to pick up some interesting gadgets on steep clearance, but with decorations and lights becoming increasingly complex over the last few years, the “Christmas Clearance” rack is an absolute must see for enterprising hackers. You might just luck out like [ModernHam] and find a couple packs of these dirt cheap wireless light controllers, which can fairly easily be hacked into the start of a home automation system with little more than the Raspberry Pi and a short length of wire.
In the video after the break, [ModernHam] walks the viewer through the start to finish process of commanding these cheap remote plugs. Starting with finding which frequencies the remotes use thanks to the FCC database and ending with using cron to schedule the transmission of control signals from the Pi, his video really is a wealth of information. Even if you don’t have this particular model of remote plug, or don’t necessarily want to setup a home automation system, there’s probably some element of this video that you could still adapt to your own projects.
The first step of the process is figuring out how the remote is communicating to the plugs. [ModernHam] noticed there was no frequency listed on the devices, but using their FCC IDs he was able to find the relevant information. In the United States, devices like these must have their FCC IDs visible (though they could be behind a battery door) by law, so the searchable database is an invaluable tool to do some basic reconnaissance on a poorly documented gadget.
An RTL-SDR receiver is then used to fine tune the information gleaned from the FCC filing. [ModernHam] found that the signals for all four of the remote plugs were being broadcast on the same frequency, which makes controlling them all the easier. Using the rtl-sdr command, he was able to capture the various signals from the transmitter and save them to separate files. Then it’s just a matter of replaying the appropriate file to get the plugs to do your bidding.
Of course, the RTL-SDR can’t transmit so you’ll have to leave your dongle behind for this last step. Luckily all you need to transmit is the rpitx package created by [F5OEO], along with a supported Raspberry Pi and a small length of wire attached to the appropriate GPIO pin. This package contains the tool sendiq which can be used to replay the raw captures made in the previous step. With some scripting, it’s fairly straightforward to automate these transmissions to control the remote plugs however you wish from the Pi.
Sure there are the occasional functional Christmas tree ornaments; we had one that plugged into the lights and was supposed to sound like a bird gently trilling its song, but was in fact so eardrum-piercing that we were forbidden from using it. But in general, ornaments are just supposed to be for looks, right? Not so fast — this 3D-printed ornament has a 3D-printer inside that prints other ornaments. One day it might just be the must-have in functional Christmas decor.
Given that [Sean Hodgins] had only a few days to work on this tree-dwelling 3D-printer, the questionable print quality and tiny print volume can be overlooked. But the fact that he got this working at all is quite a feat. We were initially surprised that he chose to build a stereolithography (SLA) printer rather than the more common fused deposition modeling (FDM) printer, but it makes sense. SLA only requires movement in the Z-axis, provided in this case by the guts of an old DVD drive. The build platform moves in and out of a tiny resin tank, the base of which has a small LCD screen whose backlight has been replaced by a bunch of UV LEDs. A Feather M0 controls the build stage height and displays pre-sliced bitmaps on the LCD, curing the resin in the tank a slice at a time.
Results were mixed, with the tiny snowflake being the best of the bunch. For a rush job, though, and one that competed with collaborating on a package-theft deterring glitter-bomb, it’s pretty impressive. Here’s hoping that this turns into a full-sized SLA build like [Sean] promises.
We played with the tree a bit, and the web interface is fairly powerful. For each LED, you can select either a random color or a keyframe-defined pattern. For the keyframe LEDs, you can create a number of “keyframes”, each of which is defined by a color and a transition, which can be either linear, quarter sine wave, or instantaneous (“wall”). Additional keyframes can be added for each LED, and if don’t specify a pattern for all the LEDs, the system repeats those you have defined to fill the entire string. There are also a few preset patterns you can choose if you prefer. If you, too, want to play with the tree, don’t delay: it’s only available through the first week of 2019!
Behind the scenes, an aging Raspberry Pi provides the local brains driving the LED controller and streaming the video, while a cloud server running a Redis instance allows communication with the web. The interface to the string of WS2811 LEDs uses [Kevin]’s Kinetis LK26 breakout board, which he managed to get working despite the state of tools and documentation for the Kinetis ARM family. You can read a good discussion of the system on his blog; there are a surprisingly large number of pieces that need to work together. As usual, he provides all the source code for this project on GitHub.
Anyone who has decorated a Christmas tree knows that the lights are what really make the look. But no matter how many strings you wrap around it, there never seems to be enough. Plus the standard sets either sit there and do nothing, or just blink on and off at regular intervals. Yawn.
But hackers aim higher, and [leo.currie]’s interactive “paintable” Christmas tree takes the lighting game a step beyond. The standard light strings are replaced with strings of WS2811 RGB LEDs which are wired to an ESP8266. A camera connected to a Raspberry Pi is setup up to stream images of the tree to all and sundry on the Interwebz, but with a special twist: it also creates a map of every light on the tree. That allows the lights to be controlled individually in response to user inputs on a web page hosted on the Pi. The upshot is that you can paint the tree with any color you like in real time, or upload various animated GIFs to display on the tree. You can play with the tree directly, or watch a replay on the video below when that Pi inevitably gets hugged to death.
Imagine the possibilities with this. Why not hang a lot of LED strings vertically from the eaves of your house and make a huge, low-resolution display? We’ve featured plenty of large, interactive LED Christmas displays before, and we’d love to see what you come up with.