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Reading is big in Québec, and [pepelepoisson]’s young children have access to a free mini library nook that had seen better days and was in dire need of maintenance and refurbishing. In the process of repairing and repainting the little outdoor book nook, he took the opportunity to install a few experimental upgrades (link in French, English translation here.)

The mini library pods are called Croque-Livres, part of a program of free little book nooks for children across Québec (the name is a bit tricky to translate into English, but think of it as “snack shack, but for books” because books are things to be happily devoured.)

After sanding and repairs and a few coats of new paint, the Croque-Livres was enhanced with a strip of WS2812B LEDs, rechargeable battery with solar panel, magnet and reed switch as door sensor, and a 3.3 V Arduino to drive it all. [pepelepoisson]’s GitHub repository for the project contains the code and CAD files for the 3D printed pieces.

The WS2812B LED strip technically requires 5 V, but as [pepelepoisson] found in his earlier project Stecchino, the LED strip works fine when driven directly from a 3.7 V lithium-polymer cell. It’s not until around 3 V that it starts to get unreliable, so a single 3.7 V cell powers everything nicely.

When the door is opened, the LED strip lights up with a brief animation, then displays the battery voltage as a bar graph. After that, the number of times the door as been opened is shown on the LED strip in binary. It’s highly visual, interactive, and there’s even a small cheat sheet explaining how binary works for anyone interested in translating the light pattern into a number. How well does it all hold up? So far so good, but it’s an experiment that doesn’t interfere at all with the operation of the little box, so it’s all good fun.

For years [Centas] dream was to take the stars to his home and build a fiber optic ceiling. Even though there are many fiber optic star ceiling kits commercially available, we are glad he decided to go full DIY on this project as the result is simply astonishing.

[Centas] chose to make a model of a section of the sky as it is visible from his home and generated a map of 1,200 stars with the planetarium software Celestia. The most time-consuming part of making a star ceiling is always poking lots of holes for the fibers. In [Cenas] case this turned out to be especially cumbersome as he decided to install the fibers after hanging the ceiling panel so he came up with a method to catch the fiber with a fishing pole after pushing it through from the bottom. The finished ceiling looks really great though with its rounded edges that contain RGB LED strips for side illumination. [Cenas] also painted the ceiling after installing the fibers so they are not visible when they are not lit but there is still enough light shining through the paint.

The electronics were divided into two parts, a transmitter installed in a laser-cut box and a receiver part mounted directly in the ceiling. The transmitter contains an MSGEQ7 graphic equalizer chip and an audio jack to make the ceiling sound reactive.

The control scheme is somewhat unusual as the transmitter receives signals from an IR remote and then forwards them to the receiver via an NRF24L01 2.4 GHz module. The receiver module adjusts the LEDs brightness via PCA9685 PWM controllers connected to some transistors and MOSFETs. The circuit actually caused some problems as LEDs started flickering at low PWM values. Apparently, this was caused by the low switching times of the MOSFETs, so [Cenas] solved it by lowering the PWM frequency.

In the video below it looks like [Cenas] also installed some illumination that can draw lines between the star constellations but in the comments he reveals that it was just done by video editing. It would be nice though to see someone building such an illumination using LED strips or side-emitting fibers.

Interestingly, other people have found ways to make similar installations by directly poking fibers through the ceiling from the room above.

If you’ve got a party coming up and are looking to add a little bit of excitement, you might be interested in this recent project from [Gav Lewis]. The build is based on a commercially available party light, but with some upgraded components the final product is brighter and more dynamic than it was stock.

Realistically, [Gav] has changed out almost every component of this light except for the enclosure and the front lens. The original 5 mm LED array was replaced with a new 8×8 WS2812B panel, and the electronics completely replaced with an Arduino Nano. He’s still using the light’s original power supply, but as it only puts out around 4.2 V, he’s added a boost converter to provide a stable 5 V for the new hardware. He also added a small 12 V cooling fan, which he says is basically silent since it’s only getting half its rated voltage.

[Gav] has developed a number of lighting patterns with FastLED that do a good job of emulating what you might see from a much more expensive laser scanner. In the video after the break, you can see how multiple colored beams of light exit the housing at once, projecting patterns on the opposite wall. He says he’s like to restore the device’s original sound activation mode, but as of yet hasn’t gotten the code sorted out.

This project uses a off-the-shelf 8×8 matrix of WS2812B LEDs, but if you ever find yourself needing to piece together your own array from individual LEDs, we recently covered a great tip for making it a bit easier.

Despite all the incredible advancements made in video game technology over the last few decades, the 8-bit classics never seem to go out of style. Even if you weren’t old enough to experience these games when they were new, it’s impossible not to be impressed by what the early video game pioneers were able to do with such meager hardware. They’re a reminder of what can be accomplished with dedication and technical mastery.

The grid has been split up for easier printing.

If you’d like to put a little retro inspiration on your desk, take a look at this fantastic 16 x 16 LED matrix put together by [Josh Gerdes]. While it’s obviously not the only thing you could use it for, the display certainly seems particularly adept at showing old school video game sprites in all their pixelated glory. There’s something about the internal 3D printed grid that gives the sprites a three dimensional look, while the diffused glow reminds us of nights spent hunched over a flickering CRT.

The best part might be how easy it is to put one of these together for yourself. You’ve probably got most of what you need in the parts bin; essentially it’s just a WS2812B strip long enough to liberate 256 LEDs from and a microcontroller to drive them. [Josh] used an Arduino Nano, but anything compatible with the FastLED library would be a drop-in replacement. You’ll also need a 3D printer to run off the grid, and something to put the whole thing into. The 12×12 shadowbox used here looks great, but we imagine clever folks such as yourselves could make do with whatever might be laying around if you can’t nip off to the arts and crafts store right now.

Beyond looking great, this project is a fantastic reminder of how incredibly handy WS2812 LEDs really are. Whether you’re recreating iconic game sprites or fashioning your own light-up sunglasses, it’s hard to imagine how we managed before these little wonders hit the scene.

Unless you’re particularly fond of looking at the back of 88 individual WS2812B LEDs, these “RGB Goggles” from [Mukesh Sankhla] won’t offer you much of a view. But from an outsider’s perspective, the smartphone-controlled glasses certainly make a statement. Just don’t try to operate any heavy machinery while wearing them.

The build starts off with a pair of shades dark enough that the lights won’t be obvious until they’re powered up. [Mukesh] then carefully aligned the LEDs into a grid pattern on a piece of clear tape so they could be soldered together with the fewest number of jumper wires possible. Even if you’re not in the market for some technicolor eyewear, this clever arrangement of WS2812B modules could come in handy if you’re looking to make impromptu LED panels.

To control the LEDs, [Mukesh] is using an Arduino Nano and an HC-06 Bluetooth module that’s linked to an application running on an Android smartphone. The software, developed with the MIT App Inventor, allows the user to easily switch between various patterns and animations on the fly. With such an easy-to-use interface, the RGB Goggles don’t look far off from a commercial product; other than the whole not being able to actually see through the thing.

We’ve actually seen a number of custom glasses projects over the years, as it seems that a cheap pair of shades make an ideal platform for head-mounted hacks. We’ve even found what may be the ideal power source for them.

Anyone who has done anything with RGB LEDs knows that their ability to display pretty much any color is somehow both the best and worst thing about them. How do you get it right? How do you make your results repeatable? [Thomas] has the answer. He dug around in the ol’ parts cupboard, found a few pots, and got to work making this stay-home stew of a project — an on-demand RGB LED color mixer.

Three cleverly color-coded potentiometers and an Arduino let [Thomas] step through 0-255 to mix various values of red, blue, and green. The shade that gets made is displayed live on a set of 10 individual NeoPixels that are laid out under a frosty diffusing panel. Each of the RGB values are also shown on an 16×2 LCD.

This is one of those projects that hits a sweet spot of being simple, useful, and fun. It’s even nice-looking and compact. What more could you want from a project cobbled together from ingredients on hand? [Thomas] is even giving away the code recipe.

Once you dial in your ideal colors, why not make a gesture-controlled lamp?

Looking to sterilize something? Give it a good blast of the old UV-C. Ultraviolet radiation in the shortest wavelength band breaks down DNA and RNA, so it’s a great way to kill off any nasties that are lurking. But how much UV-C are you using? [Akiba] at Hackerfarm has come up with the NukeMeter, a meter that measures the output of their UV-C sterilizer the NukeBox. It is built around a $2.50 sensor and a $3 Arduino.

The NukeMeter is built around a GUVA-S12SD UV sensor breakout board. This sensor is really designed for UV-A detection, but a quick look at the spec sheet revealed that it is sensitive to UV across all of the bands. So, it can be used as a UV-C sensor if you know how sensitive it is to this particular frequency band.

However, the sensor is not that sensitive to UV-C light, so [Akiba] had to do a bit of minor surgery on the circuitry that surrounds the sensor to tweak the output. The sensor was designed to measure relatively low levels of UV light (such as sunlight), and now they are blasting it with a shedload of radiation, so they have to effectively disable one of the op-amps that normally scales the output up, which involves replacing a couple of resistors. That’s a bit of a pain to do with surface mount components, but it is doable with a steady hand and a small tip soldering iron.

Next, an Arduino takes the voltage output of the sensor and converts it into a light level. The mathematics of how this works are all well detailed in the post, but it isn’t complicated, and the source code is here.

Using this, [Akiba] was able to measure how the lights performed, how quickly they warmed up and how much the light level varies along the length of the fluorescent tube.

One caveat to bear in mind here: [Akiba] designed this to measure the output of the low-pressure mercury vapor lamps they are using at Hackerfarm, which output a very narrow frequency band, peaking at 250 nM. This design would not work for a more broadband output or for one which mixed UV-C with UV-A and UV-B. For that, you would need a more sophisticated design that would probably cost more than $5.

SAFETY NOTE: Don’t mess with UV-C light sources unless you have a good idea of what you are doing and are sure that the light is contained, e.g. in a sealed box, maybe with interlocks. Remember that you also rely on DNA, and inadvertently zapping your own DNA can cause all sorts of unpleasantness.  

If everything goes according to plan, Elon Musk says the first generation of SpaceX’s massive Starship will make an orbital flight before the end of 2020. That’s a pretty bold claim, but when you’ve made landing rockets on their tails as in the old science fiction pulp magazines seem routine, we suppose you’ve earned the right to a bit of bravado. We’re excited to see the vehicle evolve over the next several months, but even if the real one stays grounded, we’ll gladly take this “flying” Starship model from [Chris Chimienti] as a consolation prize.

A magnetic levitation module, we’re officially in the future.

Feeling a bit let down by the 3D printable models of the Starship he found online, [Chris] set out to build his own. But it wasn’t enough to just make his bigger, stronger, and more accurate to Starship’s current design; he also wanted to make it a bit more exciting. Some RGB LEDs an Arduino embedded in the “cloud” stand the rocket sits on was a good start, and the landing pad inspired by SpaceX’s real autonomous spaceport drone ship Just Read the Instructions looks great all lit up.

But this is Starship we’re talking about, a vehicle that could literally push humanity towards being a multi-planet species. To do it justice, you’ve really got to knock it out of the park. So [Chris] found a magnetic levitation module online that could support a few hundred grams, and set to work on making his plastic Starship actually hover over the landing pad.

As you might imagine, it was a bit tricky. The first versions of the rocket looked great but came out too heavy, so he switched over to printing the model in so-called “spiral vase mode” which made it entirely hollow. Now far lighter and with a magnetic plate fit into the bottom, it was stable enough to float on its own. For the final touch, [Chris] added some red LEDs and a coin cell battery to the base of the Starship so it looks like the sleek craft is performing a last-second landing burn with its “impossible” full-flow staged combustion engines.

This isn’t the first time we’ve seen a model rocket with an electronic glowing cloud under it, but it’s certainly the first one we’ve seen that could levitate in mid-air. While this little rocket might not make it all the way to Mars, we wouldn’t be surprised to see it touching down on the desks of other hackers and makers in the near future.

[Peterthinks] admits he’s no cabinet maker, so his projects use a lot of hot glue. He also admits he’s no video editor. However, his latest video uses some a MAX7219 to create a 600 character scrolling LED sign. You can see a video of the thing, below. Spoiler alert: not all characters are visible at once.

The heart of the project is a MAX7219 4-in-1 LED display that costs well under $10. The board has four LED arrays resulting in a display of 8×32 LEDs. The MAX7219 takes a 16-bit data word over a 10 MHz serial bus, so programming is pretty easy.

The MAX chip can decode for seven-segment displays or just allow you to light up the outputs directly, which is what the code here does. You can cascade the chips, so it is possible to string more than one of these modules together.

The code is available on Dropbox. The code is extremely simple due to the use of the Parola library and a MAX72XX library. We’ve seen a number of projects based around this chip. Some of the uses are pretty novel.

Light painting has long graced the portfolios of long-exposure photographers, but high resolution isn’t usually possible when you’re light painting with human subjects.

This weekend project from [Timmo] uses an ESP8266-based microcontroller and an addressable WS2812-based LED strip to paint words or custom images in thin air. It’s actually based on the Pixelstick, a tool used by professional photographers for setting up animations and photorealism shots. The equipment needed for setting up the light painting sticks runs in the order of hundreds, not to mention the professional camera and lenses needed. Nevertheless, it’s a huge step up from waving around a flashlight with your friends.

The LED Lightpainter takes the Pixelstick a few notches lower for amateur photographers and hobbyists. It directly supports 24-bit BMP, with no conversion needed. Images are stored internally in Flash memory and are uploaded through a web interface. The settings for the number of LEDs, time for the image row, and STA/AP-mode for wireless connections are also set by the web interface. The project uses the Adafruit NeoPixel, ArduinoJson, and Bodmer’s TFT_HX8357 libraries for implementing the BMP drawing code, which also allows for an image preview prior to uploading the code to the microcontroller. Images are drawn from the bottom row to the top, so images have to be transformed before updating to the LED painter.

Some future improvements planned for the project include TFT/OLED support, rainbow or color gradient patterns in the LEDs, and accelerometer or gyroscope support for supporting animation.

There aren’t currently too many galleries of DIY LED-enabled light paintings, but we’d love to see some custom modded light painting approaches in the future.

This isn’t the first LED light stick we’ve seen, if you’re interested in such things.



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