3D Printing A Big LEGO Christmas Tree

December 20, 2024 by Lewin Day No comments

LEGO make lots of neat floral arrangements these days, and even little Christmas trees, too. While they’re fun to build out of tiny little blocks, they’re a little small for use as your main Christmas tree. Sadly, a bigger version simply doesn’t exist in the LEGO catalog, so if that’s your desire, you’ll have to build your own—as [Ruth] and [Ellis] did!

The concept behind the build is as you’d expect. The duo effectively just 3D printed giant versions of LEGO pieces, with which they then assembled a large Christmas tree. It sounds very straightforward, but scaling an existing LEGO design up by six times tends to come with some complications. A tactical decision was made early on to ease proceedings—the original LEGO tree had a large brown base that would take lots of printing. This was eliminated in the hopes that it would speed the build significantly. The long plastic shafts that supported the original design were also replaced with steel shafts since printing them would have been incredibly difficult to do well.

The rest of the video demonstrates the huge amount of work that went into actually 3D printing and assembling this thing. It’s pretty great to watch, and you’ll learn a lot along the way.

We’ve seen other creators try similar projects, where they 3D print their own building blocks from scratch. It normally turns out much harder than expected! No surprise when you think about all the engineering that went into perfecting LEGO all those years ago.

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Left: the traces of a flashy paper Christmas tree. Right: the finished tree on cardstock.

Flashy Paper Christmas Tree Does It With A 555

December 13, 2024 by Kristina Panos 10 Comments

‘Tis the season for holiday hacks, and [Ben Emmett] is here to remind us that we don’t necessarily need a fancy microcontroller in order to make flashy fun things happen.

Smoothing down the copper traces with a guitar pick.

Take this Christmas tree for example, which uses a 555 timer and a CB4017 decade counter in order to drive some blinking LEDs. The ICs are through-hole, making the circuit fairly accessible to new players, but there are a few SMD components that need soldering as well. (More on that later.)

Here, the 555 acts like a clock and drives a square wave. Using the clock as input, the decade counter toggles the output pins one after the other, driving the LEDs to blink in turn. Since there are only eight lights, there is a pause in the light-up pattern, but that could be fixed by wiring decade counter output #9 to the reset pin.

Although function was the main focus circuit-wise, [Ben] managed to lay the traces in the shape of a Christmas tree, which looks great. Having done a similar project in the past, he discovered that the craft cutting machine prefers thick traces and wider spaces between them. This is largely why [Ben] chose to use through-hole ICs.

After laying everything out in KiCad, [Ben] exported the copper layer image for use on the cutting machine. Once it was all cut out, he put it on transfer tape to weed out the extra copper, and get the traces onto cardstock, the final substrate.

This is such a fun project, and we love that the CR2032 that powers it also acts as the stand in its vertical holder. Hit up GitHub if you want to make one for yourself. Want something even more 3D? Check out this hollow tree we saw a few years ago.

Neodriver Ornament Brightens Up Christmas

October 21, 2022 by Lewin Day 11 Comments

Stores will sell you all kinds of gaudy holiday ornaments, but there’s nothing like the style and class achieved by building your own. [w3arycod3r] did just that, whipping up the fun and festive Neodriver Ornament.

It’s a battery-powered build, and runs off an rechargeable 18650 cell which provides several days of operation at a low duty cycle. An ATtiny85 is charged with sending out commands to various NeoPixel devices, from rings to rectangular arrays. [w3arycod3r] then designed various PCBs that could carry the hardware and battery in a well-balanced package that would hang nicely when suspended from a ribbon on a Christmas tree.

As is always the fun part with addressable LEDs, [w3arycod3r] whipped up some fun animations to suit. The 5×5 rectangular arrays of NeoPixels are able to deliver scrolling text, while another animation blips out the RNA sequence of everyone’s least favorite coronavirus, SARS-CoV-2. Getting everything to fit into a ATtiny85’s 8 KB of code space and 512 byte EEPROM was a challenge, but slimming down the Adafruit NeoPixel library and using direct AVR register manipulation in place of regular Arduino functions helped.

Overall, it’s a fun holiday build that looks great on the tree. Alternatively, consider making yourself some rheoscopic ornaments this holiday season. And, if you’ve whipped up your own fun holiday build, throw it on the tipsline!

USB LED Christmas Tree Is Making Spirits Bright

December 13, 2021 by Kristina Panos 9 Comments

[Piotr SB] knows there is no way out of the holidays; the only path is through. You’ve got to find cheer wherever and however you can, so why not cater to your own interests and build the cutest little LED Christmas tree you ever did see? And did we mention it’s USB and absolutely free (as in carols, not eggnog)?

This O-Christmas tree is made up of concentric rings that are built into a tier as you solder the LEDs. And of course you’re supposed use the LED legs as supports! One leg from each LED — 18 green and a red one for the top. Because the PCB is not quite thick enough, you’ll need to add a plastic spacer to get it to stay in the USB port. Not only is this a nice design, the snowflakes and snowman on the silkscreen totally seal the cuteness deal.

Ever get so frustrated with your Christmas tree that you want to just empty a few rounds into the thing? No? Well, you’d have a good reason to if you built this Duck Hunt ornament.

Building A Website-Controlled Christmas Tree

January 4, 2021 by Lewin Day 2 Comments

Back in the day, Christmas lights were simple strings of filament bulbs, and if you really splashed out, you could get some that flashed. These days, we expect a lot more capability out of our blinking decorations. [JT] has put together a rather nifty website-controlled setup for his own tree.

The setup is a little different than builds you may be used to. The website runs on a cloud-hosted virtual machine on Digital Ocean, rather than running locally. This allows anyone on the web to visit the site, and use the interface to control the lights on the Christmas tree. An image of the tree is used as the interface, and allows users to set the color of each individual LED on the tree. The LEDs themselves are driven from an NodeMCU ESP8266, which uses its WiFi connection to query the website itself and grab the color data as needed. [JT] has also included a secondary interface, where the chat of the Youtube livestream can be used to control the LEDs, too.

It’s a build that’s a touch more complicated than most typical online LED blinkers, but one that teaches useful skills in interfacing on the web and using virtual machines. We’ve seen other builds in this genre too; even some that are reactive to “Christmas fever” itself. Video after the break.

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Simple Christmas Tree Christmas Tree Ornament

January 1, 2021 by Anool Mahidharia 7 Comments

When the only tool you have is a hammer, every problem looks like a nail. An LED ornament for the Christmas tree can be built in any manner of simple, easy implementations. You certainly don’t need an ARM Cortex M4 CPU running at 120MHz having a mouthful of three letter features like FPU, ETM, ETB, ECC, RWW, TCM, EIC, AES, CAN bus and much, much more. But [Martin Held] built a super simple LED Christmas tree ornament using the ATSAME51 series micro-controller, which he regularly works with and had on hand, and lots of bi-color LEDs. He already had schematic symbols and programmers for the device from other projects where he uses it more extensively, so putting it all together in time for the festive season was that much faster for him, despite the fact that the micro-controller was most likely the cheapest part of the BOM, besides the passives.

At this point it might be tempting to argue that it would have been so much simpler to use addressable LED’s, such as the WS2812B or the APA102C. You can drive them using a more basic micro-controller, and not require so many GPIO pins. But using such “smart pixel” LED’s for hand assembled prototypes can sometimes lead to unexpected results. If they are not stored in sealed tape/reel form, then storage conditions can have an adverse effect leading to dead pixels. And, they need a specific baking procedure before being soldered. Doing that for a few LEDs at home can be tricky.

So for the LED’s, he again went a bit off the beaten path, selecting to use three different color styles of bi-color LED’s with easy to hand-solder, 1206 footprints. This allows him to get a fairly random mix of colors in the completed ornament.

The LED array is pseudo-charlieplexed. One terminal of each LED goes to a GPIO pin on the micro-controller and the other terminal of all the LED’s are connected to a single complimentary pair of N-channel/P-channel MOSFETs — connected in totem-pole fashion. Depending on which MOSFET is switched on via a GPIO pin driving the gate pin high or low, the second terminal of each LED gets connected to either supply or ground. In combination with the GPIO pins being driven high/low, this allows the bi-color LED to be biased in either direction. Getting each LED to emit one color is simple enough — setting all LED GPIOs low, and MOSFET gate GPIO high will bias the LEDs in one direction. Reverse the GPIO logic, and the LEDs will be biased in the other direction. If this is done slow enough, the two colors can be differentiated easily. If the driving logic is made fast, changing states every 10us, the two separate colors merge to form a third hue. With some clever bit of code, he also adds some randomness in the GPIO output states, resulting in a more appealing twinkling effect. [Martin] does a detailed walk through in the video embedded below.

If you have the same bunch of parts lying around and wish to replicate the project, be warned that the KiCad source files will need some work to clean up errors — [Martin] was in a hurry and knew what he was doing so there are some intentional mistakes in the schematic such as using the same symbol for the N-channel and P-channel MOSFETs, and uni-directional LED symbol in place of the bi-directional one. And for programming, you will need one of these pricey pogo-pin style cables, unless you decide to edit the PCB before sending off the Gerbers.

[Martin] built just three of these bespoke ornaments, retaining one and giving away the other two to a neighbour and a co-worker. But if you would really like to build a tree ornament with addressable LEDs, then check out the Sierpinski Christmas Tree which can be cascaded to form an array of tree ornaments.

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The Internet Of Christmas Tree Watering

January 1, 2021 by Jenny List 5 Comments

There’s nothing quite like a real Christmas tree, but as anyone who’s had one will know there’s also nothing like the quantity of needles that a real tree can shed when it runs short of water. It’s a problem [RK] has tackled, with a Christmas tree water level monitor that has integration with Adafruit’s cloud service to give a handy phone notification when more watering is required.

The real interest in this project lies in the sensor development path. There are multiple ways of water level sensing from floats and switches through resistive and light scattering techniques, but he’s taken the brave step of using a capacitive approach. Water can be used as a dielectric between two parallel metal plates, and the level of the water varies the capacitance. Sadly the water from your tap is also a pretty good conductor, so the first attempt at a capacitive sensor was not effective. This was remedied with a polythene “sock” for each electrode constructed with the help of a heat sealer. The measurement circuit was simply a capacitive divider fed with a square wave, from which an Adafruit Huzzah board could easily derive an amplitude reading that was proportional to the water level. The board then sends its readings to Adafruit.io, from which a message can be sent to a Slack channel with the notification enabled. All in all a very handy solution.