Simulate City Blocks With Circuit Blocks In A LEGO Box

November 12, 2019 by Kristina Panos 4 Comments

Have you ever looked around your city’s layout and thought you could do better? Maybe you’ve always wanted to see how she’d run on nuclear or wind power, or just play around with civic amenities and see how your choices affect the citizens.

[Robbe Nagel] made this physical-digital simulator for a Creative Programming class within an industrial design program. We don’t have all the details, but as [Robbe] explains in the video after the break, each block has a resistor on the bottom, and each cubbyhole has a pair of contacts ready to mate with it. An Arduino nestled safely in the LEGO bunker below reads the different resistance values to determine what block was placed where.

[Robbe] wrote a program that evaluates various layouts and provides statistics for things like population, overall health, education level, pollution, etc. As you can see after the break, these values change as soon as blocks are added or removed. Part of what makes this simulator so cool is that it could be used for serious purposes, or it could be totally gamified.

It’s no secret that we like LEGO, especially as an enclosure material. Dress it up or dress it down, just don’t leave any pieces on the floor.

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Azobenzene Stores Solar Energy

November 12, 2019 by Al Williams 30 Comments

Probably the most efficient way to convert solar energy into electricity is the old fashioned way, heating water into steam and turning a turbine. This remains a messy affair though and you don’t really want a steam boiler on your roof, so solar cells are popular. However, there’s some new research showing how a molecule can absorb solar energy, store it, and then release the heat on demand years later. This could offer new ways to collect and even transport solar power. This new molecule, derived from azobenzene, holds immense promise to change the way we work with solar power.

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Core XY Explained

November 12, 2019 by Al Williams 28 Comments

If you are building a CNC machine, a 3D printer, or even a plotter, you have a need for motion in both the X and Y directions. There are many ways to accomplish this, for example, some printers move the tool in the X direction and the bed in the Y direction while others move the entire X carriage in the Y direction and yet more use a delta mechanism. However, one of the oldest means of doing this is the Core XY method. It is interesting because both motors remain stationary and the business end moves entirely on belts or cords. This is similar to the H-Bot technique, but with some differences. [Michael Laws] has a video (see below) that explains how two stationary motors can move a tool anywhere in an XY region.

The idea behind Core XY goes back to at least old drafting tables. You can think of it as an object held by two ends of the same belt. As one end of the belt gets shorter the other end gets longer. The belts are arranged so that motion of one motor causes the tool to move at a 45 degree angle. That means you have to move both motors to go in a straight line.

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Improving Exposure On A Masked SLA Printer

November 12, 2019 by Tom Nardi 6 Comments

It’s taken longer than some might have thought, but we’re finally at the point where you can pick up an SLA 3D printer for a few hundred bucks. These machines, which use light to cure a resin, are capable of far higher resolution than their more common FDM counterparts, though they do bring along their own unique issues and annoyances. Especially on the lower end of the price spectrum.

[FlorianH] recently picked up the $380 SparkMaker FHD, and while he’s happy with the printer overall, he’s identified a rather annoying design flaw. It seems that the upgraded UV backlight in the FHD version of the SparkMaker produces somewhat irregular light, which in turn manifests itself as artifacts on the final print. Due to hot spots on the panel, large objects printed on the SparkMaker show fairly obvious scarring.

Now you might expect the fix for this problem to be in the hardware, but he’s taken it in a different direction. These printers use an LCD panel to block off areas of the UV backlight, thereby controlling how much of the resin is exposed. This is technique is officially known as “masked SLA”, and is the technology used in most of these new entry level resin printers.

As luck would have it, the SparkMaker FHD allows showing various levels of grayscale on the LCD rather than a simple binary value for each pixel. At least in theory, this allows [FlorianH] to compensate for the irregular backlight by adjusting how much the UV is attenuated by the LCD panel. He’s focusing on the printer he personally owns, but the idea should work on any masked SLA printer that accepts grayscale values.

The first step was to map the backlight, which [FlorianH] did by soaking thin pieces of paper in a UV reactant chemical, and draping them over the backlight. He then photographed the illumination pattern, and came up with some OpenCV code that takes this images and uses the light intensity data to compensate for the local UV brightness underneath the sliced model.

So far, this method has allowed [FlorianH] to noticeably reduce the scarring, but he thinks it’s still possible to do better. He’s released the code for this backlight compensation script, and welcomes anyone who might wish to take a look at see how it could be improved.

An uneven backlight is just one of the potential new headaches these low-cost “masked” SLA printers give you. While they’re certainly very compelling, you should understand what you’re getting into before you pull the trigger on one.

Haptic Games Bring Fun To The Visually Impaired

November 12, 2019 by Kristina Panos 2 Comments

No matter what your parents might say, games are good for us. They teach us to manage resources and give us dopamine rewards just like eating and mating do. Even if you’re no good at games in general, they are still a fun distraction from life.

There are so many games out there that could be enjoyed by the visually impaired, except that they rely on visuals. For example, you can play Yahtzee with nothing more than five dice, a cup, pencil and paper, and knowledge of the rules and scoring. The biggest obstacles are differentiating the dice from each other and keeping score.

One of our esteemed 2019 Hackaday Prize Top 20 Finalists is [JanThar]’s Haptic Games. [JanThar]’s growing collection of games uses 3D printing, vibration motors, and RFID to replace visual cues with sensory feedback. Yahtzee-wise, there’s a set of printed dice and scorecards. The scorecards use spherical magnets and an abacus layout. [JanThar] is also working on a Memory game to teach Braille, though it could be adapted to pure Braille for the visually impaired. Each game piece contains an RFID chip, so players can hold it up to a reader to check what they have.

Our favorite might be the PONG game that’s built on [JanThar]’s 2017 Hackaday Prize entry, the HaptiVision vest. Through the magic of a 16×8 field of vibration motors, players can track the ball’s movement across their torso and control the paddles with a sliders. There’s a brief demo of the games after the break.

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HF Propagation And Earthquakes

November 12, 2019 by Dan Maloney 25 Comments

For all the successes of modern weather forecasting, where hurricanes, blizzards, and even notoriously unpredictable tornadoes are routinely detected before they strike, reliably predicting one aspect of nature’s fury has eluded us: earthquakes. The development of plate tectonic theory in the middle of the 20th century and the construction of a worldwide network of seismic sensors gave geologists the tools to understand how earthquakes happened, and even provided the tantalizing possibility of an accurate predictor of a coming quake. Such efforts had only limited success, though, and enough false alarms that most efforts to predict earthquakes were abandoned by the late 1990s or so.

It may turn out that scientists were looking in the wrong place for a reliable predictor of coming earthquakes. Some geologists and geophysicists have become convinced that instead of watching the twitches and spasms of the earth, the state of the skies above might be more fruitful. And they’re using the propagation of radio waves from both space and the ground to prove their point that the ionosphere does some interesting things before and after an earthquake strikes.

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Superconference Interview: Sam Zeloof

November 12, 2019 by Lewin Day 2 Comments

In less than four days, the fifth Hackaday Superconference kicks off in Pasadena, California, and it’s shaping up to be a hoot. With a cavalcade of exciting workshops and talks on offer, hackers and makers are pouring in from across the globe for this celebration of software, firmware, and hardware.

Of course, the real gift of Supercon is the personalities which make up this awesome community. [Sam Zeloof] is one such luminary, well known for producing his very own silicon integrated circuits in his parent’s garage. Not content to keep this knowledge to himself, [Sam] gave an amazing talk at the 2018 Supercon on just what goes into creating your own silicon fab on a budget.

Our very own [Mike Szczys] caught up with [Sam] for an interview, discussing being inspired by the work of [Jeri Ellsworth], as well as the finer points of getting into lithography at home. [Sam] will be in attendance at the 2019 Superconference, of course. While he won’t be on the speaking circuit this year, his brother [Adam] will be presenting a talk called Thermodynamics for Electrical Engineers: Why Did My Board Melt (And How Can I Prevent It)?, which is sure to be a must-see.

You really should be there, but alas tickets have been sold out for almost two months! Never fear, we’ll be livestreaming the event. Be sure to subscribe to Hackaday on Youtube to be notified when it all kicks off, around 10 AM Pacific Time on Saturday, November 16th. If you scored tickets and are heading to Supercon, we can’t wait to see you there — the badge hacking begins early Friday morning.

Be sure to check out Sam’s interview after the break!

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