Correcting Color Blindness With DLP Projectors

About five percent of the population is colorblind to one degree or another, and for them seeing the entire spectrum from Roy to Biv is simply impossible. Their eyes simply don’t have the cones to detect certain colors. The brain is the weirdest machine on the planet, though, and with the right tricks of light, even the colorblind can see more colors than they’re accustomed to. That’s the idea behind [PointyOintment]’s entry for the 2016 Hackaday Prize: color blindness correcting goggles.

Any device that claims to correct color blindness comes with a few caveats and a slightly loose interpretation of what ‘color blindness correcting’ actually is. For the same reason you can’t see deep infrared, someone with color blindness cannot distinguish between two colors; the eye simply doesn’t have the sensors to see a specific color of light. This doesn’t mean the ability to distinguish color in color blind individuals can’t be improved, though. The EnChroma glasses use an optical notch filter to block all colors between blue and green, and between green and red. This works, because the human brain is weird enough and can adapt to nearly anything.

[PointyOintmen] isn’t going with an optical notch filter. He’s using spinning color discs from a DLP projector and 3D ‘shutter’ glasses to present the world in different shades of color many times a second. It’s weird, untested, and will take a few hours to get used to, but it is a very interesting idea. Will it allow color blind people to see more colors? That’s a semantic issue, but if you define ‘seeing color’ as being able to differentiate between two different colors, yes, it will.

The Infrared Theremin

The traditional theremin is more or less an audio oscillator with two metal rods. Using proximity sensing, one rod controls the pitch of the oscillator and the other controls the volume. [Teodor Costachiou] apparently asked himself the excellent question: Why does the proximity sensor have to use capacitance? The result is an Arduino-based theremin that uses IR sensors to determine hand position.

[Teodor] used a particular type of Arduino–the Flip and Click–because he wanted to use Click boards for the IR sensors and also to generate sound via an MP3 board based around a VS1053. The trick is that the VS1053 has a realtime MIDI mode, and that’s how this Theremin makes it tones.

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Mobile Text Reader With OCR and Text To Speech

There are devices out there that will magnify text using fancy cameras and displays, devices that will convert these to Braille, and text-to-speech software has been around for thirty years. For his entry into our Raspberry Pi Zero contest, [Markus] decided to combine all these ideas into a simple device that will turn the printed word into speech.

The impetus for [Markus]’ project came to him in the form of a group of blind computer science  students. These students used a specialized program that used specialized hardware and software such as mobile Braille terminals, OCR, and oral exams that allowed these students to study the same thing as everyone else. [Markus] wanted to produce something similar, using simple text-to-speech software instead of a complicated Braille display.

The physical design of [Markus]’ project is uniquely functional – a hand-held device with a camera up front, a Pi in the middle, and a speaker and headphone jack on the back. The hand grip includes a large battery and a trigger for telling the Pi to read a few words aloud.

The software is built around the SnapPicam and includes a lot of the functionality already needed. OCR is largely a solved problem with Tesseract, and text-to-speech is easy with Festival.

Although [Markus] is just plugging a few existing software modules together, he’s come up with a device that is certainly unique and could be exceptionally useful to anyone with a vision impairment.


The Raspberry Pi Zero contest is presented by Hackaday and Adafruit. Prizes include Raspberry Pi Zeros from Adafruit and gift cards to The Hackaday Store!
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Critter Twitter Trap Traps Critters, Pings Twitter

Got aliens in your attic? Squirrels in the skirting board? You need a trap, and [John Mangan] has come up with an interesting way to let you know that you have caught that pesky varmint: the IoT Critter Twitter Trap. By adding a ball switch, Electric Imp and a couple of batteries to a trap, he was able to set the trap to notify him when it caught something over Twitter. To do this, he programmed the Electric Imp to send a message over when a varmint trods on the panel inside the trap, slamming its door shut. The whole thing cost him less than $60 and can be seen in action after the break.

This is a pretty neat hack. I used to help with a Feral Fix program, where feral cats would be trapped, neutered and returned to the wild. This involved baiting the trap, then waiting hours in the cold nearby for the ferals to get comfortable enough to climb inside and trigger the trap. [John’s] version would only work indoors (as it uses WiFi), but it wouldn’t be that difficult to add a cell phone dongle or other RF solution to extend the range. With this hack, I could have at least waited somewhere warmer, while the trap would ping me when it was triggered.

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Raspberry Pi Zero Contest Grand Prize Winners!

The Raspberry Pi Zero Contest presented by Adafruit and Hackaday came to a close last week, as the clock struck 11:59 am on Sunday, March 13, 2016. Since then our team of judges has been working to pick the top three entries. It was a hard job sorting through nearly 150 amazing creations.  In the end though, the judges were able to pick three grand prize winners. Each winner will receive a $100 gift card to The Hackaday Store.  So let’s get to the winners!

[JohSchneider] and [Markus Dieterle] both won Pi Zero boards and went on to win $100 gift certificates. [shlonkin] didn’t win a Pi Zero, but persevered and continued working on the classroom music teaching aid even without a Zero board. The top winners aren’t the only ones who are doing well. Everyone who entered has a head start on a great project for The 2016 Hackaday Prize.

I’d like to thank Hackaday’s own [Dan Maloney], [Kristina Panos], [Sophi Kravitz] and [Brian Benchoff] who joined me to judge the contest. The entire Hackaday staff is indebted to [Limor Fried] and [Phil Torrone] over at  Adafruit for coming up with 10 live videos, and providing 10 hard to find Pi Zero boards for our winners. The biggest thanks go to the entrants. If I could send a prize out to each and every one of you, I would!

The Hacker’s Notebook: a Mission Log for Every Project

While “writing it down” might seem like common sense, it wasn’t always the case. From the times of Ancient Greece, Plato tells a story of a worried Egyptian King, who, upon witnessing the invention of writing, remarks,

“If men learn this, it will implant forgetfulness in their souls; they will cease to exercise memory because they rely on that which is written, calling things to remembrance no longer from within themselves, but by means of external marks. [1]”

To some, the notebook was a dangerous device, a thief that would rob us of our memories [2]. Fortunately, these days, there’s plenty of evidence from our Psych texts that say we humans are pretty shabby at keeping the facts straight. In fact, each time we recall a memory, we change it! Here lies the beauty of the notebook. Have an idea for a new project? Why not log it somewhere for future reference? With diligence, the notebook can become our own personal hub for spurring on new project ideas.

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Just When You Thought Magnets Weren’t Magic; Magnets Are Mechanisms

This is magic, big news, both, or neither. It’s so exciting to see magnets behave in this bizarre and wonderful way that we think it’s hard to forecast where this will go. Shown above is a pair of magnets that have several modes of operation. They attract each other, but repel when less than a centimeter apart. However, give one a twist and the two will strongly attract.

The behavior is thanks to a new process of 3D printing magnets to manipulate where the fields occur. With the behavior just described, they would function well as a cabinet latch which has soft close and positive lock, all built into two magnets.

This comes from one of our favorite YouTube channels, [SmarterEveryDay], who just toured Polymagnet — a company that has figured out how to actually print magnetic fields.

3dprinted-magnets-thumbSo how the heck does it work? Well, your standard magnet has a north face on one side, and a south face on the other — creating a magnetic loop between the two. But what if you could put north and south on the same side of the magnet, and vary their position and size? It means you can control the magnetic field down to the magnetic pixel, or as Polymagnet calls them — a Maxel.

Here you can see some magnetic film (which reacts visually to magnetic fields) put on top of the two parts of the demo magnet. The printed design is very similar to a mechanical mechanism. We’d explain more, but [Destin] does a great job teaching about the tech in the video found below.

Is this the dawn of magnetic mechanisms? We certainly have never seen anything like it.

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