A Very Modern Turing Machine Build

Mathematicians. If you let them use the concept of infinity, there’s almost nothing they won’t be able to prove. Case in point: the Turing machine. The idea is that with an infinite length of tape, one could build a thought-experiment machine with only a few instructions that should be able to compute anything that’s computable.

[Igor]’s Turing machine is one of the nicest we’ve ever seen built. The “tape” is significantly shorter than infinity, which limits the computations he can achieve, the use of 3D printing, electric contacts, and WS2812 RGB LEDs for the tape are profoundly satisfying.

A bit on the tape is portrayed as unused if the LED is off, zero if it is red, and one if it is green. Each station on the tape is indexed by a set of blue LEDs observed by the gantry of the writing head which uses a 3D printed finger and motor to change the state of each bit. Programs are stored on a home-built punch card, which gets extra geek points from us.

Watch it run through “busy beaver” (embedded below) and tell us that it’s not awesome, even if it is a couple of LEDs short of infinity.

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TritiLED Lights Up The Night, Doesn’t Make You Glow

Tritium, or 3H is an isotope of hydrogen which has been used as everything from radiolabel in analytical chemistry to a booster to kickstart the chain reaction of nuclear weapons. Lately tritium’s most common use has been in key chains and jewelry. A small amount of tritium is stored in a phosphor coated glass tube. The beta decay of the tritium causes the phosphor to glow. The entire device is called a Gaseous Tritium Light Source (GTLS).

In the USA, GTLS devices are only allowed to be used in specific cases such as watches, compasses, and gun sights (MURICA!). Key chains and jewelry are considered frivolous uses and are prohibited by the nuclear regulatory commission. Of course, you can still order them from overseas websites.

The safety of GLTS devices have been hotly debated on the internet for years. They’re generally safe, unless you break the glass. That said, we’re happy getting our radiation exposure through cool hacks, rather than carrying a low-level source around in our pockets.

Enter [Ted Yapo], an amateur astronomer. After tripping over his telescope tripod one time too many, he decided to take matters into his own hands. He’s designing TritiLED, a dim LED light source which can last for years. [Ted] is using a  Luxeon Z LED, driven with PWM by a PIC 12F508 8 bit microcontroller. Running at 26.3 μA, he estimates about a year of run time on a CR2032 watch battery, or a whopping 15 years on a pair of lithium AA cells. Sure he could have done it with a 555 timer, but using a micro means more features are just a few lines of code away. [Ted] took advantage of this by adding a high brightness mode, blink modes, and an exponential decay mode, which emulates the decay of GLTSs.

Best of all it’s all open source. [Ted] is publishing under the (CC-BY-SA) license on Hackaday.io.

Incredible Luminosity in a Portable Package

If you’ve ever wanted to bring the brightest day into the blackest night, this flashlight shall give you sight. With a 100W LED array powered by up to 32V, this thing is exceedingly bright — it clocks in at about 9000 lumens! But the best part is that all every little detail of the build was documented along the way so that we can tag along for the ride.

The all-aluminium case houses the LEDs and their heat sink, voltage regulator and display, the AD and DC adapter and converter boards and their connectors, and fans to ensure adequate ventilation. It’s powered by a custom-assembled 6400 mAh 11.1V lipo battery or DC 20V 10Amp power supply via XLR for rugged, locking connection. The battery pack connection was vacuum formed for quick-swapping, and the pack itself will sound off an alert if any of the three batteries inside the pack run out of power. A nifty added feature is the ability to check the remaining charge — especially useful if you’re looking to bring this uncommonly powerful flashlight along on camping trips or other excursions.

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Making A Networked 32X32 LED Panel Case

[Adam Haile] of [Maniacal Labs] is at it again, whipping up some LED weirdness. This project is smaller than most of his work, though: he has made a nice case that holds a 32X32 LED matrix screen, the controller, and a Raspberry Pi. Check out the build and a brief demo in the video below.

This nice 3D printable design, called the Jumbo1K, would be a good starting point if you are looking to make something with one of these screens, as it provides easy access to all of the ports on the Pi for programming, debugging and networking the device without ruining the look. It does this with a neat trick, using the keystone jacks that you put in your wall when you are rewiring your house.
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Bright Idea for a Name Tag

Looking for a quick DIY project to separate yourself from the crowd at your next business function or maker expo? Take a leaf out of [Pete Prodoehl’s] book and make your own name tag complete with blinking LED!

Minimalist, yet flashy (sorry!), this quick project can be completed inside a few hours with few resources, and is a great way to display your DIY handiwork. Continue reading “Bright Idea for a Name Tag”

Life-Size Vu Meter Gets the Party Started

There’s nothing better than making a giant version of one of your hacks. That is, other than making it giant and interactive. That’s just what [Est] has done with his interactive VU meter that lights up the party.

The giant VU meter boasts a series of IR detectors that change the colors and modes of the meter based on where the user places their hands. The sensors measure how much light is reflected back to them, which essentially function as a cheap range finder. The normal operation of the meter and the new interactivity is controlled by a PIC16F883 and all of the parts were built using a home-made CNC router. There are two addressable RGB LEDs for each level and in the base there are four 3 W RGB LEDS. At 25 levels, this is an impressive amount of light.

[Est]’s smaller version of the VU meter has been featured here before, if you’re looking to enhance your music-listening or party-going experiences with something a little less intimidating. We’ve also seen VU meters built directly into the speakers and also into prom dresses.

FPGA Powers Blazingly Fast LED Matrix Audio Visualizer

[Sam Miller], [Sahil Gupta], and [Mashrur Mohiuddin] worked together on a very fast LED matrix display for their final project in ECE 5760 at Cornell University.

Real time!
Real time!

They started, as any good engineering students, by finding a way to make their lives easier. [Sam] had built a 32×32 LED matrix for another class. So, they made three more and ended up with a larger and more impressive 64×64 LED display.

They claim their motivation was the love of music, but we have a suspicion that the true reason was the love all EEs share for unnaturally bright LEDs; just look at any appliance at night and try not be blinded.

The brains of the display is an Altera DE2-115 FPGA board. The code is all pure Verilog. The FFT and LED control are implemented in hardware on the FPGA; none of that Altera core stuff. To generate images and patterns they wrote a series of python scripts. But for us it’s the particle test shown in the video below that really turns our head. This system is capable of tracking and reacting to a lot of different elements on the fly why scanning the display at about 310 FPS. They have tested display scanning at twice that speed but some screen-wrap artifacts need to be worked out before that’s ready for prime time.

The team has promised to upload all the code to GitHub, but it will likely be a while before the success hangover blows over and they can approach the project again. You can view a video interview and samples of the visualizations in the videos after the break.

Thanks to their Professor, [Bruce Land], for submitting the tip! His students are always doing cool things. You can even watch some of his excellent courses online if you like: Here’s one on the AVR micro-controller.

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