Dirt Cheap Plywood Bike Holder

Commuting to work on a bicycle saves tons of dough, but sometimes storing your bike isn’t that easy. [Lewis] has been playing around with a few prototype bike stands and seems to have found the ticket, and it’s way cheaper –maybe even free, if you have the supplies. All you need is a single strip of plywood, and some wood screws, or wood glue! Well, that and a woodworking clamp.

The stand is designed to clamp onto 4×4 posts, or even a 2×4 stud. It’s great for storing bikes along your fence! It’s built purposefully snug, which allows you to add a small clamping force to make for a very rigid stand, suitable for even old steel-framed clunkers. Hooray for friction! Oh and if you’re happy with the location you could always get rid of the clamp and screw it in place instead.

Simple? Yup. Effective? Totally.

Oh and if it’s still crummy old winter where you live, why not beat the cold weather blues with an indoor bicycle roller?

Artist Inadvertently Builds Hodoscope

A Hodoscope is an instrument used to determine the trajectory of charged particles. It’s built out of a three-dimensional matrix of particle detectors – either PIN diodes or Geiger tubes – arranged in such a way that particles can be traced along coincident detectors, revealing their trajectory.

This is not a hodoscope. It’s a chandelier. This chandelier is made of 92 individual Geiger tubes, each connected to a single LED fixture and a speaker. When a charged particle flies through the room and hits a Geiger tube, the light fixture lights up, a ‘click’ plays on the speaker, and the entire room is enveloped in light for a short moment in time. If, however, that charged particle continues on to another Geiger tube, the trajectory of the particle can be deduced.

The purpose of the installation – beside just being art or something – is to show the viewer sources of radiation and normal levels of radioactivity due to terrestrial and cosmic sources. Of course the spacing of these detectors is rather large – it’s made to fit in a gallery – and there is no connection between the detectors, making a coincident circuit impossible. If you want a real hodoscope, here you go.

This installation can be seen at the Burchfield Penney Art Center in Buffalo, NY through April 12. If you’re in the area, go there and eat a banana. Video below. Thanks [David] for the tip.

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11,000 Volt Jacob’s Ladder Sounds Like a Lightsaber

In the high-voltage world, a Jacob’s ladder is truly a sight to behold. They are often associated with mad scientist labs, due to both the awesome visual display and the sound that they make. A Jacob’s ladder is typically very simple. You need a high voltage electricity source and two bare wires. The wires are placed next to each other, almost in parallel. They form a slight “V” shape and are placed vertically. The system acts essentially as a short-circuit. The voltage is high enough to break through the air at the point where the wires are nearest to each other. The air rises as it heats up, moving the current path along with it. The result is the arc slowly raising upwards, extending in length. The sound also lowers in frequency as the arc gets longer, and once [Gristc] tuned his system just right the sound reminds us of the Holy Trilogy.

We’ve seen these made in the past with other types of transformers that typically put out around 15,000 Volts at 30mA. In this case, [Gristc] supersized the design using a much beefier transformer that puts out 11,000 Volts at 300mA. He runs the output from the transformer through eight microwave oven capacitors as a ballast. He says that without this, the system will immediately trip the circuit breakers in his house.

In the demo video below, you can see just how large the arc is. It appears to get about 10 inches long before breaking with a sound different from any Jacob’s ladders we’ve seen in the past as well. Continue reading “11,000 Volt Jacob’s Ladder Sounds Like a Lightsaber”

Revive The Demoscene with a LayerOne Demoscene Board

Demos, the demoscene, and all the other offshoots of computer arts had their beginning as intros for cracked Apple II, Speccy, and Commodore 64 games. Give it a few years, and these simple splash screens would evolve into a technological audio-visual experience. This is the birth of the demoscene, where groups of programmers would compete to create the best demonstration of computer graphics and audio.

For one reason or another, this demoscene was mostly confined to Europe; even today, 30 years after the Commodore 64, the North American demoscene is just a fraction of the size of the European scene. A very cool guy named [Arko] would like to change that, and to that end he built the LayerOne Demoscene Board.

If there is a problem with the modern demo scene, it’s that the hardware that’s usually used – C64s, Ataris, Spectrums, and Amigas – are old, somewhat rare, and dying. There’s also the fact that artists have been working on these old machines for decades now, and every single ounce of processing power and software trickery has been squeezed out of these CPUs. [Arko]’s board is a ground-up redesign of what a board that plays demos should be. There’s only one chip on the board – a PIC24F with three graphics acceleration units, color lookup tables, and the ability to output 16-bit VGA video up to 640×480 with 8-bit audio.

The first official competition with the LayerOne Demoscene Board will be at the 2015 LayerOne conference in Monrovia, CA on May 23. There are a few categories, including 4k and 64k JavaScript, Raspberry Pi, the LayerOne board, and a ‘Wild’ category. If you want to take a processor out of a toaster and make a demo, this is the category you’ll be entering. Of course Hackaday will be there, and we’ll be recording all the demos.

Below are a few examples of what the LayerOne Demoscene board can do, and you can also see a talk [Arko] gave at the Hackaday 10th anniversary party here. You can buy the Layerone Demoscene Board on the Hackaday Store

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Deconstructing PCBs

The surest way to reverse engineer a circuit is to look at all the components, all the traces between these components, and clone the entire thing. Take a look at a PCB some time, and you’ll quickly see a problem with this plan: there’s soldermask hiding all the traces, vias are underneath components, and replicating a board from a single example isn’t exactly easy. That’s alright, because [Joe Grand] is here to tell you how to deconstruct PCBs one layer at a time.

Most of this work was originally presented at DEFCON last August, but yesterday [Joe] put up a series of YouTube videos demonstrating different techniques for removing soldermask, delayering multi-layer boards, and using non-destructive imaging to examine internal layers.

If you’re dealing with a two-layer board, the most you’ll have to do is remove the soldermask. This can be done with techniques ranging from a fiberglass scratch brush, to laser ablation, to a dremel flapwheel. By far the most impressive and effective ways to take the solder mask off of PCBs is the way the pros do it: chemically. A bath in Magnastrip 500 or Ristoff C-8 results in perfectly stripped boards and a room full of noxious chemicals. It makes sense; this is what PCB houses use when they need to remove solder mask during the fabrication process.

Removing a solder mask will get you the layout of a two-layer board, but if you’re looking at deconstructing multi-layer boards, you’ll have to delaminate the entire board stack to get a look at the interior copper layers. By far the most impressive way of doing this is with a machine that can only be described as gently violent, but passive, imaging techniques such as X-rays, CT scanners and other sufficiently advanced technology will also do the trick. Acoustic microscopy, or  Acoustic Micro Imaging, was, however, unsuccessful. It does look cool, though.

Thanks [Morris] for the tip.

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Reverse Engineer a VFD after Exploring How They Work

[Dave Jones] got his hands on a really wide, 2-row Vacuum Fluorescent Display. We’ve come across these units in old equipment before and you can get them from the usual sources, both new and used, but you need to know how to drive them. This recent installment of the EEVblog reverse engineers this VFD.

The function of these displays is pretty easy to understand, and [Dave] covers that early in the video after the break. There is a cathode wire and phosphorescent coated anodes. When current is applied the anodes glow. To add control of which anodes are glowing a mesh grid is placed between the anodes and the cathode wire. Applying negative potential to the grid prevents the electrons from traveling to the anode so that area will not be lit.

Now driving this low-level stuff is not easy, but rest assured that most VFDs you find are going to have a driver attached to them. The reverse engineering is to figure out the protocol used to control that driver. On this board there is a 2-pin connector with a big electrolytic filtering cap which is a dead giveaway for power rails. Looking at the on-board processor which connects directly he ascertains that the input will be 5V regulated since this is what that chip will expect. Connecting his bench supply yields a blinking cursor! [Dave] goes on to pump parallel data and test out the control pins all using an Arduino. He finds success, sharing many great reverse engineering tips along the way.

We often call this type of thing a dark art, but that’s really just because there aren’t a lot of people who feel totally comfortable giving it a try. We think that needs to change, so follow this example and also go look at [Ben Heckendorn’s] recent LCD reverse engineering, then grab some equipment and give it a try for yourself. We want to hear about your accomplishments!

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Sodium Pickle Lights

A few weeks ago, the folks at the 23b hackerspace held Sparklecon, an event filled with the usual infosec stuff, locks and lockpicking, and hardware. A con, of course, requires some cool demonstrations. They chose to put a pickle in an arc welder, with impressive results.

This build began several years ago when the father of one of 23B’s members pulled off a neat trick for Halloween. With a cut and stripped extension cord, the two leads were plugged into a pickle and connected to mains power. The sodium in the pickle began to glow with a brilliant orange-yellow light, and everyone was suitably impressed. Fast forward a few years, and 23b found itself with a bunch of useless carbon gouging rods, a 200 Amp welder, a pickle, and a bunch of people wanting to see something cool.

The trick to making a pickle brighter than the sun was to set the arc just right; a quarter of an inch between the electrodes seemed optimal, but even then pickle lighting seems very resilient against failing jigs made from a milk crate, duct tape, and PVC. Video (from the first Sparklecon, at least) below.

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