Delicious Optics, A Chocolate Diffraction Grating

April 16, 2018 by Lewin Day 12 Comments

Diffraction gratings are curious things. Score a series of equally spaced tiny lines in a surface, and it will cause reflected or transmitted light to bend and separate into its component wavelengths. This ability gives them all manner of important applications in the field of optics, but they’re also fun to play with. [Tech Ingredients] has done the hard work to find out how to make them out of candy!

The video starts with a basic discussion on the principles of diffraction gratings. The basis of the work is a commonly available diffraction grating, readily available online. It’s a plastic sheet with thousands of microscopic ridges scored into the surface. The overarching method to create a candy version of this is simple — coat the ridged surface in liquid chocolate or sugar syrup, to transfer the impression on to the candy surface when it solidifies. However, the video goes further, explaining every step required to produce a successful end result. The attention to detail is on the level of an industrial process, and shows a mastery of both science and candy processing techniques. If you’ve ever wondered how to properly crystallize chocolate, this video has the knowledge you need.

It’s not often we see candy optics, but we like it — and if you fail, you can always eat your mistakes and try again. If you’re wondering what you can do with a diffraction grating, check out this DIY USB spectrometer.

Custom Built Vacuum Tube Cassette Player

April 16, 2018 by Tom Nardi 40 Comments

As we’ve said many times here on Hackaday, it’s not our place to question why people make the things they make. There’s a legitimate need or utility for many of the projects we cover, no doubt about it. But there’s also a large number of them which are so convoluted that they border on absurd. Not that we love the crazy ones any less, in fact, we usually like those the best.

So when we saw this incredible modification to a Panasonic RN-404 microcassette recorder which replaces the audio hardware with a custom built vacuum tube amplifier, we didn’t bother asking what the point was. Perhaps it’s an attempt to make the most impractical method for recording and playing back audio, or maybe it was just to see if it was possible. No matter why it was done, it’s here now and it’s absolutely glorious.

If the look of the hardware didn’t tip you off that this project makes use of old Soviet-era components, the video after the break certainly will. Specifically, it’s using 1ZH25R and 1S38A tubes which were originally intended for military use. Just like all cool old Soviet tech was. Say what you will about the Cold War, it certainly got the engineering juices flowing.

There’s quite a bit of information about how these ancient tubes were brought back to life by way of this gorgeous home-etched PCB. Suffice to say, working with tubes is an art to begin with, but working with such small and unique ones is on a whole new level.

This isn’t the first time we’ve seen some tiny tubes make their way into a piece of consumer audio equipment, but this one certainly takes the top spot in terms of professional final results.

Continue reading “Custom Built Vacuum Tube Cassette Player” →

Neon Lamps Light Up Dim Ion Motor

April 14, 2018 by Steven Dufresne 6 Comments

Small pinwheel type ion motors fall into the category of a fun science experiment or something neat to do with high voltage, but Hackaday’s own [Manuel Rodriguez-Achach] added a neat twist that incorporates neon lamps.

Normally you’d take a straight wire and make 90 degree bends at either end but pointing in opposite directions, balance it on a pole, and apply a high voltage with a moderate amount of current. The wire starts spinning around at the top of the pole, provided the ends of the wire are sharp enough or the wire has a small enough diameter. If your power supply has ample current available then in the dark you’ll even see a purplish glow, called a corona, at the tips of the wire.

[Manuel] made just such an ion motor but his power supply didn’t have the necessary current to produce a strong enough corona to be visible to his camera. So he very cleverly soldered neon lamps on the two ends of the wires. One leg of each lamp goes to the wire and the other end of the lamp acts as the sharp point left out in the air for emitting the ions.

The voltage needed across each lamp in order to ignite it is that between the high voltage power supply’s output and the potential of the surrounding air. That air may be initially at ground potential but he also bends the other output terminal of the power supply such that its tip is also up in the air. This way it sprays ions of the opposite polarity into the surrounding air.

Either way, the neon lamps light up and the wire spins around on the pole. Now, even without a visible corona, his ion motor makes an awesome display. Check it out in the video below.

For more about these ion motors, sometimes called electric whirls, check our article about all sorts of interesting non-electromagnetic motors.

Continue reading “Neon Lamps Light Up Dim Ion Motor” →

Portable DVD Player Gets Raspberry Pi Zero Upgrade

April 13, 2018 by Tom Nardi 24 Comments

You might remember a time when people thought portable DVD players were a pretty neat idea. In the days before netbooks, cheap tablets, and arguably even the widespread adoption of smartphones, it seemed perfectly reasonable to lug around a device that did nothing but play movies. Today we look back at them as we would flip phones: a quaint precursor to the technology overload we find ourselves in currently. But the fact remains that millions of these comical little devices were pumped into the greedy maw of the consumer electronics market. They’re ripe for the hacking, all you need is some inspiration.

So if this grafting of a portable DVD player and the Raspberry Pi Zero W created by [nutsacrilege] doesn’t get you sniffing around your local second-hand store for a donor device, nothing will. By integrating a Pi running Kodi, the player gets a multi-media kick in the pants that arguably makes up for the rather archaic form factor. Not only can it play a wide array of local and online content, but it could even be used as portable game system if you were so inclined.

Rest assured, this isn’t some lazy five-minute mod. All of the original physical controls have been made functional by way of a MCP3008 ADC connected to the Pi’s GPIO and some clever Python scripting. Even the headphone jack was made functional by wiring it up to a USB sound card, and by integrating a tiny stripped down hub he was also able to add an external USB port. Who needs discs when you can plug in a flash drive full of content?

Speaking of which, [nutsacrilege] reports that the original functions of the device are still intact after all his modifications. So if you can get the museum to loan you one, you can even play a DVD on the thing as its creators intended.

With luck, this project will help spur on some more portable DVD player hacking, which we’ve seen precious little of so far. Frankly, it would be nice to see people cramming Raspberry Pi’s into something other than Game Boys for once.

[via /r/raspberry_pi]

Dumping Arcade ROMs The Hard Way

April 12, 2018 by Tom Nardi 13 Comments

Nostalgia is a funny thing. That desire we all get to relive past memories can make you do things that in any other scenario would be out of the question. The effect seems even stronger when it comes to old video games. How else can you explain buying the same games over and over every time they get “remastered” for the next generation of consoles? But what if those remasters aren’t good enough?

If you have a burning desire to play a 100% accurate version of certain old arcade games, you might have your work cut out for you. Getting precise ROMs from some of these machines is exceptionally difficult, and as explained on the [CAPS0ff] blog, sometimes requires nearly superhuman feats of engineering.

As explained in the blog post, less invasive methods of getting inside the Taito C-Chip had already been examined and come up lacking. Despite best efforts, sending the unlock command to the chip didn’t yield the desired effect. If you can’t read the ROM the usual way, you need to get a little creative.

The process starts by milling down the case of the chip until the integrated circuit is just starting to become visible. Then acid is used to fully expose the traces. The traces are then tinned, and some very fine soldering is done to get the chip wired up to the reader. All told it takes about three hours from start to finish to pull a ROM using this method. But it’s all worth it in the end when you can play that 100% accurate version of Rainbow Islands. Or so we’ve been told.

If you couldn’t tell, this isn’t the first time a chip has been flayed open like this on the [CAPS0ff] blog.

1920’s Claratone Radio Runs Windows 10

April 10, 2018 by Tom Nardi 31 Comments

In the past we’ve mentioned how there are different schools of thought in terms of how to bring a vintage piece of hardware into the 21st century. You can go down the preservationist’s route, carefully grafting the original components with more modern ones, or you can take the nuclear option and blow all that dusty old gear out of the water. [Derek Traxler] clearly decided to go with the latter option on his recent conversion of 1920’s era Claratone tube radio to an Internet radio and podcast player. Not only is there little left of the original device beyond its knobs and wooden case, but he’s even managed to cram a Windows 10 computer into the base for good measure.

The core of the radio is a LattePanda, an extremely powerful Intel single board computer. It’s running Windows, and loads up a list of Internet radio streams and podcasts to play from a USB thumb drive that’s built into an old vacuum tube. The LattePanda uses its built-in Arduino to interface with the radio’s original front panel knobs, which now are used to switch between streams. A particularly neat effect is the static and cross-talk that’s artificially added when switching “stations”, making it sound like you’re really dialing in a station rather than just selecting between digital files.

On the audio side, the LattePanda is connected to a SX400 amplifier, which in turn drives the external speakers. While [Derek] mentions it isn’t quite perfected, a MSGEQ7 graphic equalizer chip is used to control LEDs mounted inside the original radio’s vacuum tubes. In the video after the break, you can see the tubes flashing madly along with the music, giving an interactive effect to the final product. Unfortunately it seems you can only see the tubes when the radio has its “hood” up, though.

If this egregious lack of historical preservation has brought a tear to your eye, never fear. We’ve covered some proper restoration work on vintage audio gear which may level you out.

Continue reading “1920’s Claratone Radio Runs Windows 10” →

Orbital Mechanics On A Vintage Kaypro

April 8, 2018 by Dan Maloney 18 Comments

These days, a good proxy for hacking prowess is getting Doom playable on the oldest piece of hardware imaginable. While we respect and applaud these efforts, perhaps the bar should be set a bit higher. Like orbital mechanics on an early 80s Kaypro, perhaps?

At least that’s the hurdle [Chris Fenton] set for himself as a fun project for his spare time with his Kaypro 2/84, a vintage Z80 clocking in at a screaming 4 MHz and 64-kB of RAM. With its built-in 80×25, 9″ green phosphor CRT monitor and flip-top keyboard, the Kaypro fit into that loveable luggable category of machines and predated IBM’s and Apple’s market dominance by a few years. The CP/M operating system has actually aged pretty well — but well enough to port [Chris]’ Deep Dish Nine, a graphical game written for the Arduboy that uses Kerbal-like orbital mechanics skills to deliver interplanetary pizzas? In the first instance, no — the game, ported to Turbo Pascal, only managed fractional frames per second, rendering it unplayable. But with some very clever coding, [Chris] was able to improve refresh rates 10-fold. The optimization road not taken includes hardware hacks, like overclocking the Z80 or even replacing it with an FPGA and emulator, but that’s hardly keeping with the spirit of the thing.

It’s always great to see vintage machines pushing the envelope. A great place to see them is one of the Vintage Computer Fairs, like the upcoming VCF Southeast in Georgia. We were at the one diagonally across the country a few weeks back, and they’re well worth the trip.