Holograms Can’t Be Too Thin

June 3, 2017 by 28 Comments

We’ve seen the 3D phone fad come and go, with devices like the Evo 3D, that used a parallax barrier to achieve autostereoscopy (that is, 3D viewing without glasses). These displays aren’t holograms, they are just showing your eyes two different images like a 3D movie or a stereopticon. However, researchers from Australia and China are hoping to change that. They’ve developed a nano-hologram (their term) that is about 1000 times thinner than a human hair. You can see a video about the invention, below.

Conventional holograms modulate the phase of light to give the illusion of three-dimensional depth. But to generate the required phase shifts, those holograms need to be as thick as the optical wavelengths involved. The researchers claim the holograms are “simple” to make, but that depends on what you compare it to. You need some exotic materials, vacuum deposition gear, and a laser that can do femtosecond-long pulses.

The research team has broken this thickness limit with a 25 nanometer hologram. Their technique relies on a topological insulator material a novel quantum material that holds a low refractive index in the surface layer but a much higher refractive index in the bulk of the material. This forms an intrinsic optical resonant cavity which can enhance the phase shifts and makes holography possible.

The next step is to develop a rigid thin film to overlay an LCD screen. The current version has pixels at least ten times too large to be practical for that application, so that’s another hurdle to overcome.

We’ve seen screens that shoot 3D images on movies like Star Wars for years. This isn’t it yet, but it is the next step. Imagine a phone, a wrist watch, or a contact lens that could generate a holographic image. Or a garbage-can-sized robot.

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Antique Pinball Machine Lives As Clock

June 3, 2017 by 10 Comments

A big problem with restoring old arcade or pinball machines is finding original parts to get them running again. That’s part of the fun, though; when something finally works after weeks or months of effort. On the other hand, sometimes the only hope for old parts that will never be in a pinball machine again is for [Randy] to come across them. One of those parts he had lying around was a backglass for an old machine, and decided to turn it into a unique word clock.

The original pinball machine was built in 1956, and despite its age the backglass had almost no signs of wear or damage. There are 43 lights on this particular machine which is more than enough for 12 hours, minutes (by the 10s), seconds, and a few extras. An ATtiny85 serves as the controller and drives a fleet of Neopixels hidden in the display. There are also three buttons which control the brightness and allow the time to be set.

Be sure to check out the video below of this one-of-a-kind clock in action. A lot more went into this build as well including framing the glass, giving it a coat of paint and polish, and programming the clock into the microcontroller. Old backglasses from pinball machines seem to be relatively popular to repurpose into more conventional clocks, too, even clocks of an atomic nature.

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Fluorescence Microscopy Meets DIY Fluid Management

June 3, 2017 by 3 Comments

Fluorescence microscopy is an optical technique that incorporates fluorescence or phosphorescence (as opposed to reflection and absorption) in order to study the properties of organic and inorganic substances. Not a stranger to bringing DIY techniques into the lab, [Philip] is using 3D printing resources to advance science and delight interns from labs everywhere.

In fluorescence microscopy, a huge limiting factor that decreases the amount of data that can be gleaned from a single sample is the number of targets that can be labeled with fluorescent tags. However, overlap in the spectral emissions of fluorophores limits the fluorophores that can be used side-by-side. This means that only around four targets can be labeled with fluorescent tags in a typical setup, with ten being the absolute maximum if careful spectral demixing is done. However, in a single sample, there might be a few hundred components. Clearly, we’re off by an order of magnitude (or more).

However, researchers are smart. One current solution is to label targets in a sequential manner with probe signal nullification steps in between. Ideally, probes are introduced in sequential without moving the sample off of the microscope. After imaging, the probes can be removed, allowing the number of labeled targets to be limited only to the number of rounds of probe replacement. And, with clever ‘barcoding’ schemes, the returns from each round can even scale exponentially, rather than linearly.

But, to accomplish this feat, a single sample must be processed through the labeling and stripping steps repeatedly. It’s not uncommon to do this by hand, consisting of many hours of exceptionally tedious work. That’s where [Philip] comes in. By using a 3D printer like Cartesian robot, [Philip] is automating the labeling and stripping steps resulting in happy interns and ultimately a more precise product. Rather than spending a few tens of thousands on a commercial machine, you can find all of [Philip’s] design files in his GitHub repo and make one for ~ $1k. Ready for more? We’ve got your back.

Video after the break.

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Super Mario World Jailbreak Requires No External Hardware

June 3, 2017 by 24 Comments

[SethBling] has released a Super Mario World jailbreak that allows players to install a hex editor, then write, install and run their own game mods. What’s more is this all works on unmodified cartridges and SNES hardware. No hardware hacks required.

[Seth] is quick to say he didn’t do all this alone. This mod came to be thanks to help from [Cooper Harasyn] who discovered a save file corruption glitch, [MrCheese] who optimized the hex editor, and [p4plus2] who wrote some awesome mods.

While no soldering and programming of parts are required, installing this mod still requires quite a bit of hardware. Beyond the SNES and cartridge, you’ll need two multitaps, three controllers, and clamps to hold down buttons on the controllers. Even then the procedure will take about an hour of delicate on-screen gymnastics. Once the jailbreak is installed though, it is kept in savegame C, so you only have to do it once.

What does a hex editor allow you to do? Anything you want. Mario’s powerup state can be edited, one memory location can be modified to complete a level anytime you would like. It’s not just modifying memory locations though – you can write code that runs, such as [p4plus2’s] sweet telekinesis mod that allows Mario to grab and move around any enemy on the screen.

It’s always awesome to see old video game hardware being hacked on by a new generation of hackers. We’ve seen similar work done on Super Mario Brothers 3, and an original GameBoy used to pilot a drone, just to name a couple.

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Integrated Circuit Reverse Engineering, 1970s Style

June 2, 2017 by 11 Comments

We are used to stories about reverse engineering integrated circuits, in these pages. Some fascinating exposés of classic chips have been produced by people such as the ever-hard-working [Ken Shirriff].

You might think that this practice would be something new, confined only to those interested in the workings of now-obsolete silicon. But the secrets of these chips were closely guarded commercial intelligence back in the day, and there was a small industry of experts whose living came from unlocking them.

Electron micrograph of a wire bond to the Z80 CTC die
Electron micrograph of a wire bond to the Z80 CTC die

Integrated Circuit Engineering Corporation were a Scottsdale, Arizona based company who specialised in semiconductor industry data. They have long since been swallowed up in a series of corporate takeovers, but we have a fascinating window into their activities because their archive is preserved by the Smithsonian Institution. They reverse engineered integrated circuits to produce reports containing detailed information about their mechanical properties as well as their operation, and just such a report is our subject today. Their 1979 examination of the Zilog Z80 CTC (PDF) starts with an examination of the package, in this case the more expensive ceramic variant, then looks in detail at the internal construction of the die itself, and its bonding wires. We are then taken in its typewritten pages through an extensive analysis of the circuitry on the die, with gate-level circuits to explain the operation of each part.

The detail contained in this report is extraordinary, it is clear that a huge amount of work went into its production and it would have been of huge value to certain of Zilog’s customers and competitors. At the time this would have been extremely commercially sensitive information, even if it now seems like a historical curiosity.

The Z80 CTC is a 4-channel counter/timer peripheral chip for the wildly succesful Z80 8-bit microprocessor, in a 28-pin dual-in-line package. We were surprised to find from a quick search that you can still buy this chip from some of the usual suppliers rather than the surplus houses, so it may even still be in production.

If IC reverse engineering takes your fancy, take a look at our archive of [Ken Shirriff] posts.

Thanks [fortytwo] for the tip.

540 PCBs Make A Giant LED Cube

June 2, 2017 by 21 Comments

Just about anyone can make a simple LED cube. But what if you want to make a 1-meter cube using 512 LEDs? [Hari] wanted to do it, so he created two different kinds of LED boards using EasyEDA. There are 270  of each type of board, for a total of 540 (there are only 512 LEDs, so we guess he got some spares due to how the small boards panelized). The goal is to combine these boards to form a cube measuring over three feet on each side.

To simplify wiring, the boards are made to daisy chain like a cordwood module. However, to get things to line up, each column of LED boards have to rotate 90 degrees. You can see several videos about the project below.

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USB Charger Fooled Into Variable Voltage Source

June 2, 2017 by 25 Comments

USB chargers are everywhere and it is the responsibility of every hacker to use this commonly available device to its peak potential. [Septillion] and [Hugatry] have come up with a hack to manipulate a USB charger into becoming a variable voltage source. Their project QC2Control works with chargers that employ Quick Charge 2.0 technology which includes wall warts as well as power banks.

Qualcomm’s Quick Charge is designed to deliver up to 24 watts over a micro USB connector so as to reduce the charging time of compatible devices. It requires both the charger as well as the end device to have compatible power management chips so that they may negotiate voltage limiting cycles.

In their project, [Septillion] and [Hugatry] use a 3.3 V Arduino Pro Mini to talk to the charger in question through a small circuit consisting of a few resistors and diodes. The QC2.0 device outputs voltages of 5 V, 9 V and 12 V when it sees predefined voltage levels transmitted over the D+ and D- lines, set by Arduino and voltage dividers. The code provides function calls to simplify the control of the power supply. The video below shows the hack in action.

Quick Charge has been around for a while and you can dig into the details of the inner workings as well as the design of a compatible power supply from reference designs for the TPS61088 (PDF). The patent (PDF) for the Quick Charge technology has a lot more detail for the curious.

Similar techniques have been used in the past and will prove useful for someone looking for a configurable power supply on the move. This is one for the MacGyver fans.

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