Give kids some responsible and challenging tasks, and you’d be surprised at the results. The “Anything Goes” exhibit at the National Museum in Warsaw was aimed as a museological and educational experiment. A group of 69 children aged 6–14 was divided into teams responsible for preparing the main temporary exhibition at the museum. Over six months, they worked on preparing the exhibition during weekly four-hour meetings. They prepared scripts, provided ideas for multimedia presentations, and curated almost 300 works for display. One of those was [Robert Mordzon]’s Giant Interactive Crossword.
The build is in two parts. The letter tiles, which have embedded RFID tags, obviously look like the easiest part of the build. The table, looking at the video (after the break), probably needed a lot more effort and labour. It is built in two halves to make construction easier. There are a 130 boxes that need to be filled in with the right letters to complete the crossword. Each box contains a bunch of electronics consisting of an Arduino Nano, a RFID Reader and a bunch of sixteen WS2812B LEDs, all assembled on a custom PCB. Do the math, and you’ll figure out that there’s 2080 LEDs, each capable of sipping 60 mA at full brightness. That’s a total current requirement of almost 125 amps at 5 V. Add in all the Arduino’s, and [Robert] needed a beefy 750 W of power, supplied via four switch mode power supplies.
Each Arduino Nano is a slave on the I²C bus. The I²C master is an Arduino Mega 2560, which in turn communicates with a computer over serial. When a box is empty, the LEDs are dim, when a wrong letter is placed, they turn Red, and when the right letter is placed, they turn Green. If a word gets completed, a special word animation is played. This information is also passed on to the computer, which then projects an animation related to the word on a giant wall screen. Upon the crossword getting completed, the table erupts in to a sound (via the computer) and light “disco” show and also reveals the main motto of this section of the exhibit – “Playing the Hero”.
If you have OCD, then the worst thing someone could do is give you a bowl of multi-coloured M&M’s or Skittles — or Gems if you’re in the part of the world where this was written. The candies just won’t taste good until you’ve managed to sort them in to separate coloured heaps. And if you’re a hacker, you’ll obviously build a sorting machine to do the job for you.
Use our search box and you’ll find a long list of coverage describing all manner and kinds of sorting machines. And while all of them do their designated job, 19 year old [Willem Pennings]’s m&m and Skittle Sorting Machine is the bees knees. It’s one of the best builds we’ve seen to date, looking more like a Scandinavian Appliance than a DIY hack. He’s ratcheted up a 100k views on Youtube, 900k views on imgur and almost 2.5k comments on reddit, all within a day of posting the build details on his blog.
As quite often happens, his work is based on an earlier design, but he ends up adding lots of improvements to his version. It’s got a hopper at the top for loading either m&m’s or Skittles and six bowls at the bottom to receive the color sorted candies. The user interface is just two buttons — one to select between the two candy types and another to start the sorting. The hardware is all 3D printed and laser cut. But he’s put in extra effort to clean the laser cut pieces and paint them white to give it that neat, appliance look. The white, 3D printed parts add to the appeal.
Rotating the input funnel to prevent the candies from clogging the feed pipes is an ace idea. A WS2812 LED is placed above each bowl, lighting up the bowl where the next candy will be ejected and at the same time, a WS2812 strip around the periphery of the main body lights up with the color of the detected candy, making it a treat, literally, to watch this thing in action. His blog post has more details about the build, and the video after the break shows the awesome machine in action.
The WS2812 is an amazing piece of technology. 30 years ago, high brightness LEDs didn’t even exist yet. Now, you can score RGB LEDs that even take all the hard work out of controlling and addressing them! But as ever, we can do better.
Riffing on the ever popular Adafruit NeoPixel library, [Harm] created the WS2812FX library. The library has a whole laundry list of effects to run on your blinkenlights – from the exciting Hyper Sparkle to the calming Breathe inspired by Apple devices. The fantastic thing about this library is that it can greatly shorten development time of your garden-variety blinkables – hook up your WS2812s, pick your effect, and you’re done.
[Harm]’s gone and done the hard yards, porting this to a bevy of platforms – testing it on the Arduino Nano, Uno, Micro and ESP8266. As a proof of concept, they’ve also put together a great demonstration of the software – building some cute and stylish Christmas decorations from wood, aluminium, and hacked up Christmas light housings. Combining it with an ESP8266 & an app, the effects can be controlled from a smartphone over WiFi. The assembly video on YouTube shows the build process, using screws and nails to create an attractive frame using aluminium sheet.
This project is a great example of how libraries and modern hardware allow us to stand on the shoulders of giants. It’s quicker than ever to build amazingly capable projects with more LEDs than ever. Over the years we’ve seen plenty great WS2812 projects, like this sunrise alarm clock or this portable rave staff.
As always, blink hard, or go home. Video after the break.
There’s something about clocks — sooner or later, every hacker wants to build one. And we end up seeing all kinds of display techniques being used to show time. For the simplest of builds, 7-segment display modules usually get dug up from the parts bin. If you have a bunch of “smart” LED’s (WS2812’s, APA102’s), then building your own custom 7-segment modules isn’t too difficult either. [rhoalt] had neither, but he did have several 8 LED Neopixel rings lying around. So he thought of experimenting with those, and built a ‘Binoctular’ LED clock which uses the Neopixel rings as 7 segment displays.
Each digit is made using one pair of Neopixel rings, stacked to form a figure of eight. All the digits are composed of arcs, so readability isn’t the best but it’s not hard either. [rhoalt] does mention that the display is easier to read via blurred camera images rather than visually, which isn’t surprising. We’re long used to seeing numbers composed of straight line segments, so arc segmented digits do look weird. But we wouldn’t have known this if [rhoalt] hadn’t shown us, right ? Maybe a thicker diffuser with separator baffles may improve the readability.
The rest of the build is pretty plain vanilla — an Arduino Nano clone, a DS3231 RTC, a Lithium battery, and some buttons, all housed together in a laser cut enclosure which follows the figure of eight design brief. And as usual, once you’ve built one, it’s time to improve and make a better version.
Sure we can have our kids back up against a wall, force them to stand up straight, and use a ruler on their head to mark their height on the wall, but what kind of hacker would we be? There isn’t a single microcontroller or any electronic component involved! The DIY-family that calls themselves [HomeMadeGarbage] stood tall and came up with a high-tech tool to measure their kid’s height.
In place of the ruler they got a small wooden box to place on the head. Under the box, at the rear end facing down, they mounted a VL53L0X laser ranging sensor. With a range of 2 meters it’s sure to work with any child. But the box has to be sat level on the child’s head, otherwise the laser will be pointing down at an angle. To handle that they put an MPU6050 6-axis motion sensor in the box along with an Arduino Nano to tie it all together. A LCD display, measurement push-button and LED are mounted outside the box on the rear facing side.
To use it, a parent sits the box on the child’s head, making sure the laser sensor isn’t blocked and can see the floor. The LCD shows the height, along with the acceleration in the x and y directions. The LED is red if the box isn’t level and green if it is. Holding the measurement button pressed puts the tool in measurement mode and when it’s level, the LED turns blue and the LCD display freezes so you can make a note of the height. You’re good for a while, depending on your child’s age. See it being used to measure a child after the break as well as an additional clip showing what the output looks like when waving a hand up and down below it.
The Brasilia Lady comes with a 300 ml brass boiler, a pump and four buttons for power, coffee, hot water and steam. A 3-way AC solenoid valve, wired directly to the buttons, selects one of the three functions, while a temperamental bimetal switch keeps the boiler roughly between almost there and way too hot.
To reduce the temperature swing, [Rhys] decided to add a PID control loop, and on the way, an OLED display, too. He designed a little shield for the Arduino Nano, that interfaces with the present hardware through solid state relays. Two thermocouples measure the temperature of the boiler and group head while a thermal cut-off fuse protects the machine from overheating in case of a malfunction.
Also, the Lady’s makeup received a complete overhaul, starting with a fresh powder coating. A sealed enclosure along with a polished top panel for the OLED display were machined from aluminum. [Rhys] also added an external water tank that is connected to the machine through shiny, custom lathed tube fittings. Before the water enters the boiler, it passes through a custom preheater, to avoid cold water from entering the boiler directly. Not only does the result look fantastic, it also offers a lot more control over the temperature and the amount of water extracted, resulting in a perfect brew every time. Enjoy [Rhys’s] video where he explains his build:
How do you earn a place in a flower festival with a handful of Arduinos and a 3D printer? By building a water curtain that draws flowers. That’s exactly what Tecnoateneu Vilablareix, a hacking community in Spain did. They built this project specifically for Temps de Flors, a popular annual gathering in Girona, Spain. More than just a flower festival, the event opens gardens and courtyards of culturally importance to the general public that are closed the rest of the year.
The water curtain uses four Arduino Nanos to control the valves, which work in pairs to draw flowers, words, and patterns. A Mega provides a wifi connection to receive commands. Over 16 continuous days worth of print time went into the 128 valves and 64 nozzles that make up the water curtain. It took the group around 24 iterations to get the valve design just right—they have to be able to shut off quickly.
There’s an eight-video playlist after the break and a special video that shows how much we love pandering. Most of the ones in the playlist are quite short and demonstrate the final version of the water curtain. Others show the valve testing. The last is a time-lapse of the group setting it up at the festival. If you’re in the area, the festival runs until May 15th.