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Swans, Pigs, and the CIA: An Unlikely Radio Story

อังคาร, 11/24/2015 - 01:01

Shortwave radio is boring, right? Maybe not. You never know what intrigue and excitement you might intercept. We recently covered secret number stations, and while no one knows for sure exactly what their purpose is, it is almost surely involving cloaks and daggers. However, there’s been some more obvious espionage radio, like Radio Swan.

The swan didn’t refer to the animal, but rather an island just off of Honduras that, until 1972, was disputed between Honduras and the United States. The island got its name–reportedly–because it was used as a base for a pirate named Swan in the 17th century. This island also had a long history of use by the United States government. The Department of Agriculture used it to quarantine imported beef and a variety of government departments had weather stations there.

You might wonder why the United States claimed a tiny island so far away from its shores. It turns out, it was all about guano. The Guano Islands Act of 1856 allowed the president to designate otherwise unclaimed territory as part of the United States for the purpose of collecting guano which, in addition to being bird excrement, is also important because it contains phosphates used in fertilizer and gunpowder. (Honestly, you couldn’t make this stuff up if you tried.)

However, the most famous occupant of Swan Island was Radio Swan which broadcast on the AM radio band and shortwave. The station was owned by the Gibraltar Steamship Company with offices on Fifth Avenue in New York. Oddly, though, the company didn’t actually have any steamships. What it did have was some radio transmitters that had been used by Radio Free Europe and brought to the island by the United States Navy. Did I mention that the Gibraltar Steamship Company was actually a front for the Central Intelligence Agency (CIA)?

Swan Island (From Google Earth (c) 2015 DigitalGlobe, Data SIO, NOAA, U.S. Navy, NGA, GEBCO, Google)

In 1960 the United States and Cuba were not very happy with each other. Castro’s revolution had booted United States companies off of the island nation (while keeping their assets) and was friendly with the Soviet Union. Not that Castro didn’t have his reasons (see the Kahn Academy video below if you want some context). The CIA decided to use Radio Swan (which is just south of the western tip of Cuba) to broadcast propaganda into Cuba, although its 50,000 watt AM transmitter and 7,500 watt shortwave transmitter also carried commercials.

In 1961, however, the station announced it would no longer carry political broadcasts and switched to an all news format on multiple frequencies. The news, however, carried coded messages, presumably to Cuban dissidents.

Then on April 17, 1961 the United States attempted to start a revolt against Castro using a CIA-sponsored military group known as Brigade 2506. Radio Swan played a part. Depending on who you believe, Radio Swan either broadcast the coded order to start the uprising or it sent a mystery message to confuse the Cuban government into thinking there was more to worry about from internal dissidents. What isn’t in question is the message was something you wouldn’t normally hear on the radio:

Alert! Alert! Look well at the rainbow. The fish will rise soon. Chico is in the house. Visit him. The sky is blue. The fish will not take much time to rise. The fish is red.

After that, Radio Swan issued explicit instructions for Cubans to join the revolt. None of them did, the invasion was a disaster, and the United States’ involvement became clear.

After the fiasco, The Gibraltar Steamship Company transformed into Vanguard Service Corporation and Radio Swan eventually became Radio Americas. It ceased transmitting in 1968.

So next time you think listening to shortwave radio is boring, just remember you never know what you might hear. A ship in distress, an intrepid operator in Antarctica, or a spy starting a revolution. You never know.

The video below is a good discussion of the Bay of Pigs and the context that surrounded it. The Bay of Pigs directly pushed Castro to be more mistrustful of the United States and cemented his relationship with the Soviets. This would eventually lead to the Cuban Missile Crisis, which could have easily escalated into a global nuclear war (especially when Charles Maultsby accidentally flew a U-2 spy plane into Soviet airspace; but that’s another story).

Filed under: Hackaday Columns, radio hacks

The Antikythera Mechanism

จันทร์, 11/23/2015 - 23:31

It’s no secret that a great deal of Western civilization was informed by the ancient Greeks. They revolutionized mathematics and geometry, developing astronomy along the way. They built ornate statues, beautiful temples to the gods, and amphitheaters for live entertainment with astonishing acoustics. The influence of the ancient Greeks shaped almost every field of human knowledge, from the arts and architecture to politics, philosophy, science, and technology.

This article was written for the Omnibus vol #02
Order yours now

Like the Babylonians, the Greeks paid close attention to the night sky. Our nearest celestial neighbor, the Moon, was particularly important to them from a planning perspective. For instance, debts might be due on the new Moon. By heeding the Moon’s phases and taking note of eclipse cycles, they found that their harvests were more fruitful, and they had fewer incidents at sea.

As savvy and well-rounded as ancient Hellenistic culture appears to have been, it’s not unreasonable to imagine that the Greeks could have created some kind of computing machine to make their Moon-centered scheduling easier. Based on fragments from in a shipwreck that was discovered in 1900, it seems they did exactly this. Based on scientific dating of the coins and pottery found in the wreck and inscriptions on the bronze remnants, historians and scientists believe the Greeks created a mechanical computer capable of calculating the positions of the Sun and the Moon on any given day. This marvelous device is known as the Antikythera mechanism.

The mechanism was housed in a wooden box and controlled with a knob on one side. It is believed that the front of the box was a display made up of a set of concentric rings with graduations, and that each ring corresponded with one celestial body. Pointers attached perpendicularly to output gears moved around the rings as the knob was turned, showing the paths and positions of these celestial bodies over time. This Earth-centric planetarium also displayed the phase of the Moon as well as the positions of the five major planets known to the ancient Greeks—Mercury, Venus, Mars, Jupiter, and Saturn.

Gearing // Composite Plan

Provided the scientific dating of the coins and pottery found among the shipwreck is correct, the Antikythera mechanism also marks the earliest appearance of the differential gear. It is believed that the designer used a pin and slot arrangement to join two gears of differing tooth counts in order to model and compensate for the irregular, elliptical orbit of the Moon. Through a complex series of gearing ratios, this ancient computer could predict solar and lunar eclipses, displaying models of them at the user’s fingertips just as they would happen in the sky.

Storms and Shipwrecks

It’s a wonder the Antikythera mechanism was discovered at all. In 1900, a group of Greek sponge divers were sailing back to Symi, an island in the Rhodes region of Southern Greece. Their ship was in a channel north of Crete, near the small island of Antikythera. They became caught in a storm and were forced take shelter around the island’s main port of Potamós. Once the storm passed, they decided to scout the area for sponges before returning home.

The divers didn’t find any sponges off the coast of Antikythera, but they did find treasure. Among the steep rock shelf below laid the remains of a large ship. Scattered among the ancient timbers, partially obscured by rock and silt, the divers could see the disembodied heads, arms, and legs of large bronze and marble statuary. After recovering what they were able to haul, the captain took note of their bearings and the two ships set sail for Symi.

At eight miles square, Antikythera is a fraction the size of Kythera, the island it opposes in the Sea of Crete. Because of its dimensions, location, and low levels of human activity, the island has long been a major stop for migratory birds. Antikythera has seen a lot of fluctuation in usage over the last few thousand years, and the current population is around fifty inhabitants. Because of its staggering cliff faces and craggy shoreline, the tiny island has been a big hazard for all of maritime history.

The sponge divers and crew spent the next six months figuring out what to do about the treasures they had found. Rather than loot the wreckage site, they decided to notify the standing authorities about their discovery. The ship’s captain went to Athens with a bronze arm that his crew had found in the wreck. Almost immediately, the government sanctioned an official recovery mission.

It was agreed that the crew of sponge divers who made the discovery would revisit the site and turn whatever they found over to the Greek government. They ended up recovering the largest collection to date of artifacts from classical antiquity. They brought back scores of treasure from the ancient Hellenistic period, including corroded bronze fragments of something they couldn’t identify. All of the artifacts went to the National Archaeological Museum in Athens.

Believe it or not, the bronze fragments that comprised the Antikythera Mechanism more or less sat around unnoticed at the museum for eight months after the exploration. This was due to the sheer volume of bronze brought into the museum from the wreck. It required a lot of sorting and re-sorting as statues and other pieces were catalogued and reconstructed by the staff. During one of these re-shufflings, someone noticed inscriptions and graduation markings on one of the fragments, and they began to receive attention befitting the oldest known mechanical computer.

Shortly after the exploration of the shipwreck in 1901, it was reported that the fragments of the mysterious object comprised some sort of astrolabe, a type of inclinometer used to locate the positions of celestial bodies. A naval historian named Konstantin Rados contested this theory, arguing that it was too complex of an instrument to be a mere astrolabe. Albert Rehm, a scholar of ancient language and textual interpretation, loosely compared it to the Sphere of Archimedes, a device the ancient Greek mathematician used for computing the volume and surface area of a sphere with relation to those of a cylinder.

Gears from the Greeks

The first in-depth analysis of the Antikythera mechanism was performed by a British science historian and Yale professor named Derek de Solla Price. He began his study of the fragments in the 1950s, using still photographs and radiographs to make sense of the gear ratios. Price’s examination continued unabated into the 1970s. In June of 1974, he published his findings with the American Philosophical Society in a monograph called Gears from the Greeks: The Antikythera Mechanism: A Calendar Computer from Ca. 80 B.C. The 72-page labor of love is Price’s full inquiry into the matter, ranging from the happenstance of the shipwreck’s discovery and early explorations of the mechanism to all that he finds conclusive and inconclusive about its origins, inner workings, meaning, and the shortlist of possible creators.

Gearing // Back of Main Plate

Price leaves no fragment unexamined, but he was limited by the technologies available at the time. In Gears from the Greeks, he writes that every visible cog was so corroded that not a single one could yield an accurate tooth count. He nevertheless took the task on, working with artist Beverly Pope to create the intricate line drawings you see reprinted here.

Through extensive use of radiography, Price came to the conclusion that the mechanism contained at least 27 gears. It’s now believed that the complete mechanism contained at least 30 gears.

Price was sure that if he could get an accurate count of any of the gears’ teeth, he could begin to unlock the mysteries of the mechanism. This was quite a difficult task to undertake, given that he was working with two-dimensional x-rays of gears that meshed here and overlapped there in a very tight configuration. Undaunted, he literally traced around the gears to count the teeth. Price believed the largest gear was made with 223 or 225 teeth and represented the Sun. He wasn’t sure of this gear’s exact significance, and proposed that a gear representing the eclipse cycle would have 223 teeth, while a gear standing for the Metonic cycle would have 235 teeth.

Price also counted a gear with 127 teeth, and supposed that it could have been used to follow the moon’s movement around the Earth. This number is significant as it is equal to half the number of Moon orbits in a 19-year solar cycle. Scientists believe that the mechanism’s creator did this to simplify the operation, and that a multiplier gear converted the number to 254.

No one had visited the site of the wreck since the initial dredging in 1901. In 1976, an expedition led by Jacques Cousteau recovered many more objects that helped provide clues to the age of the Antikythera mechanism. Among the ship timbers and bronze figures, Cousteau and his team found bronze and silver coins from the Asia Minor colonies of Pergamon and Ephesus, which are now part of Turkey. A coin expert named Panagiotis Tselekas was able to date these coins as having been struck between 70 and 60 BC. Cousteau’s team had also recovered pieces of pottery and many large wine jugs, which experts were able to date to 65-50BC.

All of the available evidence points to the likelihood that the ship was an immense trading vessel belonging to the Roman Empire. At the time, only a few ports in the Mediterranean such as these three were big enough to handle a ship of its enormity, and it was probably sailing from Asia Minor back to Rome. The ship was heavily laden with objects, which many researchers believe that the Romans had looted from Pergamon, Ephesus, and Rhodes.

New Technology, New Findings

Several years later, a mechanical engineer and former curator of London’s Science museum named Michael Wright performed his own extensive study of the Antikythera mechanism over a period of twenty-five years. Wright studied Derek de Solla Price’s monograph and ultimately concluded that Price’s reconstruction of the mechanism was fundamentally incorrect. In fact, Wright went so far as to call it bizarre and incomplete, suggesting that Price took some creative liberties to fill in the gaps, and to make the astronomical calculations work out against his gear tooth counts.

But Michael Wright didn’t just throw stones. In addition to writing numerous papers about the mechanism, he collaborated with Australian computer historian Allan Bromley to create a complete reconstruction of the device in bronze and wood, drawing upon his mechanical knowledge and the history of craft techniques. Wright also took his own photographs of the fragments and performed radiography with a device he created to adapt X-ray equipment for this purpose. Together, they created plans for the model by compiling data from hands-on examination and from their own measurements of the delicate fragments.

Gearing // Front of the Main Plate

The front display of Wright’s model was an Earth-centric planetarium with indicators for the Sun, Moon, and the five major planets of ancient Greek astronomy. In creating his reconstruction, Wright attempted to stay as true to the original as the radiographs would prove. He machined gears from thin bronze that measured between one and two millimeters thick, which he proposed was the kind of stock that all of the metallic parts of the mechanism were made from.

A few years later, an international team of scientists with access to much better imaging technology confirmed that the largest gear did indeed bear 223 teeth. This particular gear was crucial to reconciling the 12-month solar year with the 29.5-day lunar month—a cycle of 19 solar years exactly equals 235 lunar months. This number 235, which indicates what the Greeks referred to as the Metonic cycle, is repeated in a series of individual graduations on the back of the mechanism. In Michael Wright’s model, a spiral groove with a resettable arm predicted the dates of solar and lunar eclipses as an output function of the internal gearing.

One of Wright’s most insightful suppositions about the device was that the gearing that drove the display on the back side, where eclipse prediction takes place, appeared to have a pin and slot mechanism. His adapted x-rays revealed a slot and the ghost of a circular piece inside of it. Wright ultimately determined that the pin gear and the slot gear pivot on slightly offset axes. Both are connected to the 223-tooth gear, which keeps track of the Moon’s orbit. This meant that the pin and slot mechanism was a differential gearing solution designed to compensate for the irregular, elliptical orbit of the Moon around the Earth.

Another of Wright’s contributions was his discovery of a fixed boss in the main fragment. This suggests that the Antikythera mechanism was designed to show epicyclical motion with subsystems that moved about a central gear. Wright believed that the Antikythera mechanism had likely been altered, or hacked, if you will at one or more points after it was made. Primarily, he supposes the two spiral output displays on the rear of the device were repurposed from some other piece of equipment and added later, citing the appearance of the enclosure’s remains.

Around the time that Michael Wright was studying the mechanism and creating his reconstruction, a team of scientists, astronomers, and mathematicians had come together in Athens to further research the ancient calendar computer. They worked in conjunction with the Antikythera Mechanism Research Project (AMRP) to continue investigation into the mechanism and published an article in 2006 detailing their findings about the machine.

Shortly after publication, British mathematician and filmmaker Tony Freeth of the AMRP collaborated with Alexander Jones, a professor of the History of Exact Sciences in Antiquity at New York University’s Institute for the Study of the Ancient World. Together, they came up with a computer model of the Antikythera mechanism that incorporates newer knowledge about the device.

In 2005, Tony Freeth engaged scientists from Hewlett-Packard who had created a special technique for creating enhanced images of the surfaces and details of paintings. A dome covered with lamps flashes light on the object in question from various angles while a series of still photos are taken. Freeth convinced them to go to Athens and use this equipment to photograph the tiny inscriptions on the mechanism. The images did wonders for furthering the team’s understanding. They were able to confirm once and for all that the largest gear definitely had 223 teeth. Another inscription directly mentions the number ‘235’ as well as the spiral display on the back with reference to the Metonic cycle.

Freeth and Jones were able to use the month inscriptions to help determine where the Antikythera Mechanism was made. At the time of the shipwreck, each of the Greek states used its own calendar scheme. The month inscriptions on the fragments pointed to Corinth, or a colony of Corinth such as Syracuse on the island of Sicily.

How it Works – the Current Model

Years of study, measurement, photographs, and educated guesswork by several people have provided an increasingly clear picture of the mechanism’s structure. Essentially, it is a collection of gear wheels that was likely contained in a wooden box and operated with a hand crank on the side. As the crank was turned, the indicators on the front would spin around, each modeling the path of one of the major celestial bodies known to the ancient Greeks. There were separate indicators for the Sun, Moon, and five major planets known at the time. The device’s smallest indicator was a tiny sphere, colored half black and half white by those who would later model it. This little ball spun independently of its indicator arm, showing the phases of the Moon as it moved through each day of the solar calendar.

Gearing // Side View

According to Michael Wright, the inner workings contain multiple gear trains for the calendar year, including the true Sun and mean Sun. Two subsystems emerge from this train, one based on the Sun and one on the Moon. The Sun side contains gearing that computes the four-year cycle of the Pan-Hellenic Olympic Games as well as the nineteen-year Metonic cycle, which is a common multiple of both the solar year and the lunar month. It also computes the seventy six-year Callippic cycle, which is four times the length of the Metonic cycle and was proposed by Greek astronomer Callippus around 330BC as an improvement over the Metonic cycle.

The ancient Babylonian astronomers had discovered what Edmund Halley would come to call the Saros cycle, which describes the full cycle of eclipse activity between the Sun and the Moon. The Babylonians found that every 223 synodic (lunar) months, the Sun, Moon, and Earth return to the same relative geometry, resulting in the same type of eclipse.

The lunar gear train connects to a lunar anomaly platform and on to an eclipse gear train that shows the 223-month Saros cycle and its proposed improvement, the 669-month Exeligmos cycle. There are additional epicyclical gearing mechanisms for the five major planetary bodies known to the ancient Greeks: Venus, Mercury, Mars, Jupiter, and Saturn.

These internal gearing systems output their calculations on the back of the device through two spiral grooves. One is divided to show the calendar cycles for the Olympic Games, the Metonic cycle, and the Callippic cycle. The other acts as an eclipse predictor, operating on the 223-month Saros cycle to show the dates of both solar and lunar eclipses. A pointer spans the radius of each ring of the groove, while an attached needle rides in the slot. This design made it possible to reset the output by lifting the pointer as one would lift the arm of a record player.

Who Made the Antikythera Mechanism?

Derek de Solla Price believed there were a few people who could have created this technological wonder. One of them was Andronicus Kyrrhestes, a Macedonian who had built a kind of ancient weather station called the Tower of Winds. His octagonal structure featured a wind vane and a complex sundial on each of its faces. A frieze around the exterior of the tower paid homage to each of the eight prevailing wind gods. Inside the tower was a clepsydra, or water clock, which was driven by water from the Acropolis.

If not Kyrrhestes, Price supposes the Antikythera mechanism was conceived by some Rhodes engineer studying under Posidonios, a renowned philosopher and meteorologist who took a great interest in measuring the distances to the Moon and stars. If the Antikythera mechanism had been the work of Archimedes, Price believes that his name would certainly have been attached to it in historical records, followed closely by a great deal of praise for having invented the differential gear. In his book, De Republica, Cicero described a device he had seen while studying at Rhodes. This was a planetarium constructed by Posidonios. In his writing, Cicero wrote of some novel differences between this new planetarium and an earlier astronomical device he greatly admired, the sphere of Archimedes.

The Future of the Antikythera Mechanism

Until recently, there had only been two officially sanctioned recovery missions of the Antikythera shipwreck: the original dredging, and Jacques Cousteau’s expedition in 1976. But in September and October of 2014, a group of divers, archaeologists, and scientists returned to the site in partnership with the Hellenic navy. With the help of some cutting-edge diving gear, they were able to recover even more objects, ranging from common tableware to treasures of antiquity, such as the giant bronze spear belonging to a life-sized warrior statue.

Enclosure Theory

The group had many goals for this expedition. One of these was to map the full extent of the shipwreck with a 3D digital blueprint. A bright yellow autonomous underwater vehicle (UAV) named Sirius took care of that by providing high-resolution stereo images. Sirius was built by the marine robotics arm of the Australian Centre of Field Robotics at the University of Sydney.

Because the ship’s remains are so far underwater, diving to the site and staying for more than a few minutes is terribly dangerous. The group’s other main goal was testing a new diving suit technology called the Exosuit, which allows for dives down to 1,000 feet. With these suits, the divers could safely stay down at the wreck for over 30 minutes a day.

Antikythera Admiration

Both Michael Wright’s physical bronze model and Tony Freeth’s computer model of the mechanism greatly moved the needle of understanding with regard to its inner workings and reason for creation. Wright is not the only craftsman who is moved by the mechanism’s mechanical marvels. In 2010, an Apple engineer named Andrew Carol completed a working replica of the mechanism which he constructed entirely from LEGO Technic pieces.

Carol’s model is much larger than the original device, mostly due to the difference between custom-machining brass gears and modeling the same oddly-numbered cogs with pre-formed ABS gears. It also uses about twice as many gears as the original, mostly because Carol had to reckon with the way the calendar has changed over the last 2,000+ years.

In early 2014, a USC mechanical engineering student modeled the Antikythera mechanism using Solidworks. He based his files on Tony Freeth’s and Alexander Jones’ gearing proposal. He has shared the CAD files through his site, theshamblog.com, noting that they are not quite fit for 3D printing in their current state. In December 2014, he made comment about his plan to release a version intended for lasers and wood.

A Mystery Wrapped in an Enigma

There are many layers to the mystery of the Antikythera mechanism. For instance, it could have been one of a kind, or it may be the only one of many such computers to survive from antiquity.

And what was the Antikythera mechanism doing at the bottom of the Sea of Crete? Was it looted from a Greek colony along with hundreds of works of art and pieces of jewelry, or was it among the Roman shipwreck’s remains by coincidence? In his monograph, Derek de Solla Price discusses the Antikythera mechanism as a historical document, offering the point that much of what remains from ancient Greek society are the sturdier pieces of evidence like architecture, jewelry, and pottery. No Hellenistic artifact had yet been found that was anywhere near as complex as the Antikythera mechanism. Prior to its discovery, the earliest-surviving object of similar complexity dates from 1000A.D—an astrolabe created by a Persian scholar named al-Bīrūnī.

After the fall of the ancient Greek civilization, it is believed that the kind of craftsmanship and technology the mechanism represents moved east through the Byzantine Empire and on to the Arabs after the fall of Constantinople. Complex mechanical clockwork on a smaller scale began to appear in Central Europe around the end of the Middle Ages, and the automata that much of modern technology emerged from in the Victorian Era.

Diagrams Reprinted by Permission

Diagrams reprinted by permission
Gears from the Greeks: The Antikythera Mechanism–A Calendar Computer from ca. 80 B.C.
by Derek De Solla Price (ISBN 9780871696472, published November, 1974)

This article was specifically written for the Hackaday Omnibus vol #02. Order your copy of this limited edition print version of Hackaday.

Filed under: Featured

Pre-order this Graphically Stunning Print Edition of Hackaday

จันทร์, 11/23/2015 - 22:01

Now is your chance to hold a piece of Hackaday in your hands. Last year we announced our first ever print edition. We continue that tradition with a much bigger offering. Hackaday Omnibus vol #02 gathers the best content from Hackaday over the last year. This includes in-depth original content, incredible art, the events that mattered over the last 12 months, and a few cryptic easter eggs.

[Joe Kim], Hackaday’s Art Direct, really outdid himself with the cover this year. Inspired by an epic movie, the illustration includes a shoutout to almost every article found within. Of course there is a lot more of his work inside, along with the efforts of dozens of writers, artists, editors, and more.

All 128 pages of Omnibus vol #02 were painstakingly laid out by [Aleksandar Bradic] who enlisted the help of a dedicated core of Hackaday.io members to help pore over the final drafts, ensuring the presentation is immaculate. Along the way some of them teamed up to roll in those easter eggs that I previously mentioned. We don’t even know what all of it means, you should be the first to solve the mystery.

Most of the 31 articles that grace these pages have run past the front page of Hackaday. But there are a few that were written specifically for the print edition. These will be published on our front page starting in 90 minutes and continuing for a few weeks. It is important to us to share these great works without the need to purchase anything. But the Omnibus is truly one of the coolest pieces of tech literature that you can own. It deserves a place on your coffee table, reception area at work, and as a gift for all who love to know how things work, how things were built, and the legacy of knowledge that has come from generations of hacking.

We’re only running a single printing of this gorgeous volume. Make sure you get one of your own by placing a pre-order now. Be one of the first 500 using coupon code OMNIBUS2015 and get it for just $10! Show that you support great content and help make future projects like this possible.

Filed under: Featured, Hackaday Store, slider

3 Billion Devices And A Sega Genesis Run Java

จันทร์, 11/23/2015 - 19:01

A few years ago, [Mike]’s friend gave him an old Sega Genesis with the very cool and somewhat rare SegaCD drive attached. The SegaCD gave him an idea – while it’s not easy to burn a cartridge and play homebrew games on a real Genesis console, everyone has a CD burner somewhere. [Mike] began writing his demo and then realized adding Java would be easy on the 68000. The result is Java on three billion devices and a Sega Genesis.

This project is built around Java Grinder a Java byte code compiler that will compile classes, factories, and all the horrible Java design.design.pattern.pattern.patterns() into assembly language. Already, there are a lot of platforms supported by Java Grinder, including the Commodore 64, the TI99, and thanks to some work from [Joe Davisson], the Apple IIgs

With a byte code compiler, an assembler, and an API for the Sega-specific hardware, [Mike] set about building his demo. Since this was a Sega, it needed the ‘SEGA’ sound at the start. [Mike] ended up recording his voice saying ‘JAVA!’ This plays through the Z80 on the Genesis.

The complete demo – viewable in its emulated format below – has everything you would expect from a proper demo. Starfields, dancing sprites, and even a Mandelbrot pattern make it into the three-minute long demo.

Filed under: classic hacks

Laser Cutting Bathymetric Maps

จันทร์, 11/23/2015 - 16:01

Bathymetry is the underwater equivalent to topography. And with the right map data, you can make some amazing 3D laser cut maps that feature both land masses — and the details under the sea. [Logan] just learned how to do this, and is sharing his knowledge with us.

[Logan] holds the typical hacker belief: The best way to learn something is just to start the project and figure it out as you go. Which also makes him an excellent candidate for helping others to learn what not to do. His goal of the project was to create a visually stunning map of Vancouver that helps to emphasize the depth of the ocean just off the coast.

To do this he obtained bathymetry data from the Fisheries and Oceans of Canada, and city map data from Open Street Map, a service we’re very familiar with that has provided data for many cool hacks, like this Runner’s GPS unit. The tricky part now is combining the data in order to laser it.

Enter QGIS, a free and open source geographical information system that allows you to edit and combine map data, and the best part — export to .dxf.

After he was happy with his new map file, it was time to get cutting. This will be pretty tedious depending on how much detail you decided to use, but the end result is oh so worth it.

Once it was all done, he also stained the ocean layers blue to give it more depth — if you wanted to get really creative, you could also do a dyed blue epoxy fill which would allow you to still see the detail — but look like water!

For more information on how to make laser cut maps of your city, check out this other project we covered last year — funny enough — also based in Vancouver.

Filed under: laser hacks

USB Volume Control

จันทร์, 11/23/2015 - 13:01

If you buy expensive computer speakers, they often have a volume knob you can mount somewhere on your desk so you aren’t dependent on the onboard volume control. [Kris S] decided to build his own version of the remote volume control. Not surprisingly, it uses an Arduino-compatible Digispark board and a rotary controller. The Digispark (that [Kris S] bought for $2) is compatible with the Adafruit Trinket. This is key because the Trinket libraries are what make it easy to send media keys over the USB (using the HID interface) to control the volume.

Really, though, the best part of the build is the good looking knob made out of a pill bottle (see the video below). The micro Digispark is small enough to fit in the lid of the pill bottle, and some wax and pellets add some heft to the volume control.

The standard Arduino library has trouble sending multimedia keys, but in a previous post I built a gesture-based volume control that managed to pull it off.  We’ve also covered a similar volume control in the past. That one is also very good looking, but was a more complicated build than what [Kris S] pulled off here.

Filed under: Arduino Hacks, peripherals hacks

Control Your HTPC With Scavenged IR Parts

จันทร์, 11/23/2015 - 10:01

If you’ve built yourself a home theater PC, one of your highest priorities is probably coming up with a convenient control solution. The easiest way to do this is to simply use something like a wireless keyboard and mouse. But, that’s not very conducive to an enjoyable home theater experience, and it feels pretty clunky. However, if you’ve got the right components lying around, [Sebastian Goscik] has instructions and an Arduino sketch that will let you control your HTPC with any IR remote control.

There are a number of ways you could control your HTPC, and we’ve featured more than one build specifically for controlling XBMC over the years. Unfortunately, most of those methods require that you spend your hard earned money (which is better spent on popcorn). [Sebastian’s] setup can be replicated with things you probably have on hand: an Arduino, an IR remote, and a scavenged IR receiver. The IR receiver can be found in many devices, like old stereos or TVs that themselves were controlled via an IR remote.

It starts with an Arduino Sketch that lets you can see on the serial monitor what code is being generated by the button presses on your remote. These are then scripted to perform any task or function you like when those buttons are pushed. The most obvious use here is simple directional control for selecting your movies, but much more complex tasks are possible. Maybe someone can program a T9 script to type using the number buttons on most remotes?

Filed under: Arduino Hacks, home entertainment hacks

Hackaday Links: November 22, 2015

จันทร์, 11/23/2015 - 07:00

There’s a new documentary series on Al Jazeera called Rebel Geeks that looks at the people who make the stuff everyone uses. The latest 25-minute part of the series is with [Massimo], chief of the arduino.cc camp. Upcoming episodes include Twitter co-creator [Evan Henshaw-Plath] and people in the Madrid government who are trying to build a direct democracy for the city on the Internet.

Despite being a WiFi device, the ESP8266 is surprisingly great at being an Internet of Thing. The only problem is the range. No worries; you can use the ESP as a WiFi repeater that will get you about 0.5km further for each additional repeater node. Power is of course required, but you can stuff everything inside a cell phone charger.

I’ve said it before and I’ll say it again: the most common use for the Raspberry Pi is a vintage console emulator. Now there’s a Kickstarter for a dedicated tabletop Raspi emulation case that actually looks good.

Pogo pins are the go-to solution for putting firmware on hundreds of boards. These tiny spring-loaded pins give you a programming rig that’s easy to attach and detach without any soldering whatsoever. [Tom] needed to program a few dozen boards in a short amount of time, didn’t have any pogo pins, and didn’t want to solder a header to each board. The solution? Pull the pins out of a female header. It works in a pinch, but you probably want a better solution for a more permanent setup.

Half of building a PCB is getting parts and pinouts right. [Josef] is working on a tool to at least semi-automate the importing of pinout tables from datasheets into KiCad. This is a very, very hard problem, and if it’s half right half the time, that’s a tremendous accomplishment.

Last summer, [Voja] wrote something for the blog on building enclosures from FR4. Over on Hackaday.io he’s working on a project, and it’s time for that project to get an enclosure. The results are amazing and leave us wondering why we don’t see this technique more often.

Filed under: Hackaday Columns, Hackaday links

Inferno OS on Raspberry Pi

จันทร์, 11/23/2015 - 04:01

Unix isn’t the only operating system that came out of Bell Labs. In an effort to decouple hardware from user interfaces over a network, Bell also developed an OS named Plan 9 (named after the famously bad Ed Wood movie).  While Plan 9 is still in use, it never got the momentum that Unix did. In 1996, Bell Labs (now AT&T) decided to shift its focus to Inferno, an operating system  that was meant to challenge Java as a cross-platform virtual machine environment. Now LynxLine Labs has ported Inferno to the Raspberry Pi.

Not only did they do the work, they documented it in 26 labs if you want to follow along. Or, you can just head over to the project page and get the results along with updates (judging from the commit log, the project is under active development).

Dante would be proud, as the company that is now maintaining Inferno is  named Vita Nuova Holdings. The virtual machine is named Dis, the base language is Limbo, and the communications protocol is named Styx. Styx, by the way, is identical to the latest Plan 9 file system protocol.

Given its heritage, it isn’t very surprising that Plan 9 and Inferno share a lot of common ideas. In particular, all resources are files, even network resources. Styx manages all communications to resources, both local and remote. It isn’t quite the same as Raspberry Pi, but Sandia National Labs has even ported Inferno to an Android phone (see video below).

If you are looking for more education on using the Pi for OS development, we found a course for that. If you are impressed that Plan 9 and Inferno make all resources look like files via software, don’t forget that you can do it with hardware, too.

Filed under: Raspberry Pi

The First Radio Sets: a Spark Gap and a Coherer

จันทร์, 11/23/2015 - 01:01

[Ashish] let us know about his experiments in recreating the earliest type of radio set: a spark-gap transmitter and iron-filings coherer. He goes through the historical development of the kit in great detail, so we’re just going to skip that part. Go read it yourself!

Instead, we’re going to tease you with the coolest part of the rig: the coherer. In [Ashish]’s build, it’s a piece of tubing with some iron filings between two bolts. When a sufficiently strong EM wave hits the filings, they stick together and bridge the gap between the bolts, allowing electricity to flow and light up an LED, for instance. You can see this in [Ashish]’s video below the break, along with kmore discussion of that coherer.

A coherer is a one-shot receiver — the filings have to be physically separated after each reception. Repeatedly tapping on the coherer by hand must have gotten old pretty quickly: period coherers included a “decoherer” — an electromechanical tapper that reset the coherer multiple times per second by hitting it, and contribute to a low buzzing sound when receiving with one.

Human ingenuity being what it is, there were many advances in coherer design over a few decades before crystals made them entirely obsolete. We love peering into these technological cul de sacs and finding that they were full of cleverness. We hope [Ashish] keeps playing around with coherers.

Most of us at Hackaday are licensed amateur radio operators, and we should definitely note that a spark-gap is a ridiculously broadband emitter, and you’re probably transmitting on all sorts of frequencies for which you don’t have a license. The fact that [Ashish]’s signal is strong enough to move iron filings across the room suggests that he might also be interfering with other people’s radio in the neighborhood, or further. A quick check with an AM radio, for instance, would be indicative.

It does look like it’s possible to get permission to run an experimental spark gap transmitter in the form of a Special Temporary Authority from the FCC, though, so all is not lost. If anyone else knows something about legally operating a spark-gap transmitter, please post up in the comments. The retro tech is cool enough that you know people are going to be trying this — let’s see if we can find a way to do so responsibly?

[Ashish] suggested to us that a coherer can probably make a pretty decent lightning detector. We know what our next quickie project is going to be.

Filed under: radio hacks

GNU Radio Drives Oscilloscope

อาทิตย์, 11/22/2015 - 22:01

These days we are spoiled with a lot of cheap test equipment. However, you can do a lot of measurements with nothing more than an oscilloscope. Add something like a signal generator and you can do even more. One classic technique for frequency measurement, for example, is using a scope to display a Lissajous pattern. [Franz Schaefer] has a video showing how to generate these useful curves with GNU Radio.

As we pointed out earlier, GNU Radio doesn’t have to be about radio–it is really just a Python-based signal processing laboratory. [Franz] uses GNU Radio Companion to create blocks which in turn create the patterns on an old analog scope.

So why do you care about Lissajous patterns (other than they make your scope look like a prop in a 1950s science fiction movie)? The pattern is the result of driving the X axis of the scope with one frequency and the Y axis with another (usually, the X axis is time). By plotting the two frequencies against each other, you can tell a lot about the two signals.

If  the two signals have exactly the same frequency and phase, you will get a nice 45 degree sloping line on the display. If the phase is different, the line will form an ellipse or a circle or a line with a different slope depending on the relative phase (see figure left).

The pattern gets more interesting if the frequencies differ. The resulting pattern almost looks like something generated with a Spirograph toy. By counting the loops, you can determine the relationship between the two signals. For example, a 2:1 frequency ratio makes a little bow tie on the scope (two loops).  As you can see in the image above, higher frequency ratios make more loops. You can see more examples in the video below or–even better–load up GNU Radio and try it on your own scope. For the very lazy, you can just use your Web browser.

Why would you want to measure phase? Maybe you are building a transformer. The patterns, by the way, are special cases of a harmonograph, and if you are more a mechanical hacker than an electronics hacker, we have another suggestion for you.

Phase shift pattern “Lissajous phase” by Krishnavedala – Own work. Licensed under CC BY-SA 3.0 via Commons – https://commons.wikimedia.org/wiki/File:Lissajous_phase.svg#/media/File:Lissajous_phase.svg

Filed under: tool hacks

“Who is John Galt?” Finally Answered

อาทิตย์, 11/22/2015 - 19:01

For those who haven’t read [Ayn Rand’s] philosophical tome Atlas Shrugged, there’s a pretty cool piece of engineering stuffed in between the 100-page-long monologues. Although fictional, a character manages to harness atmospheric static electricity and convert it into kinetic energy and (spoilers!) revolutionize the world. Harnessing atmospheric static electricity isn’t just something for fanciful works of fiction, though. It’s a real-world phenomenon and it’s actually possible to build this motor.

As [Richard Feynman] showed, there is an exploitable electrical potential gradient in the atmosphere. By suspending a tall wire in the air, it is possible to obtain voltages in the tens of thousands of volts. In this particular demonstration, a hexacopter is used to suspend a wire with a set of needles on the end. The needles help facilitate the flow of electrons into the atmosphere, driving a current that spins the corona motor at the bottom of the wire.

There’s not much torque or power generated, but the proof of concept is very interesting to see. Of course, the higher you can go the more voltage is available to you, so maybe future devices such as this could exploit atmospheric electricity to go beyond a demonstration and do useful work. We’ve actually featured the motor that was used in this demonstration before, though, so if you’re curious as to how a corona motor works you should head over there.

Filed under: drone hacks

Laser-cut Cardboard Planetary Gearset is Pretty, but Useless

อาทิตย์, 11/22/2015 - 16:01

[Shane] made a project that speaks directly to our heart — combining laser cutting, cardboard, and gears. How could it be any better? Well, it could do anything. But that’s quibbling. It’s fun enough just to watch the laser-cut cardboard planetary gears turn. (Video after the break.)

It was made on a laser cutter using the gear extensions for generating gears in Inkscape, everybody’s favorite free SVG editor.

In his writeup, [Shane] touches on all of the relevant details: all of the gear pitches need to be the same, and the number of teeth in the sun gear (in the center) needs to equal the number of teeth in the ring (outside) divided by the number of planets (orbiting, in the middle). So far so good.

We’re watching it go for a few minutes, and then thinking to ourselves, isn’t something else supposed to be turning? How does this thing transmit power?

[Diagram courtesy: Eric Pierce, via Wikipedia]A quick Wikipedying yielded the answer. It doesn’t have a race connecting the planets together! The planets rotate the sun just fine, but without tying them together and driving something else, it’s all just a show.

We demand satisfaction! [Shane] you owe us a carrier race. We e-mailed [Shane] directly. He said that was his next step, but there’s nothing like a lighthearted public shaming for project motivation!

In the meantime, get your gear fix by ogling this planetary-gear based clock or this retrotechtacular Army film.

Filed under: cnc hacks, misc hacks

The Easiest Infinity Mirror Build

อาทิตย์, 11/22/2015 - 13:01

Infinity mirrors are awesome. They’re great conversation pieces, and even more fun to stare into forever and ever and ever and ever… They can be tricky to build, but there’s actually a really easy way to do it, and [William] shows us how.

The way a infinity mirror works is it uses a one-way mirror with lights around the perimeter in front of a regular mirror. The majority of the light gets bounced back and forth between the two mirrored surfaces, and because you can see into the one-way mirror, you get that really cool infinity effect.

Now if you went out and bought a one way mirror, built the frame, and put it all together — it’d be a lot of work. But there’s an easier way to do it on the cheap. Mirrored car tint foil. Although it’s illegal on your car in most states, it’s still pretty easy to find. 

Take a nice shadowbox frame from an art store, with enough depth to allow for a strip of RGB LEDs.

Apply the car tint to the inside of the glass pane. Find a mirror of the same size to place behind the frame.

Glue it all together, and you’re ready to rock.

If you’re feeling a bit more ambitious, why not make an infinity mirror clock?

Or how about an LED matrix infinity mirror?

Or maybe a portal for your hackerspace?

Filed under: led hacks

Physical Fitness for the Truly Lazy

อาทิตย์, 11/22/2015 - 10:01

We’re going to get in shape around here, starting today. Well… in the United States, it is almost Thanksgiving, so we might as well wait until… but then it is going to be the end of the year and between Christmas, Hanukkah,  and New Year’s, we should put it off until then.

OK, we get it. There’s always some excuse. We know we should go on and do some push ups today. Of course, we are a lazy bunch, so not everyone’s going to do a full push up. Then we’ll all argue how many we actually did. If this sounds like you, maybe you need an Arduino-based project that counts proper push ups.

Project designer [jckelley] made use of some Grove sensors (the Seeed Studio system to plug many types of sensors and other devices into an Arduino) to connect an infrared sensor to an Arduino-pin compatible computer (a LinkIt, which is an ARM-based platform, also from Seeed). There’s an LCD to show the count, and also audio feedback, so you can hear you’ve done a full push up without having to look at the display.

If you really get bit by the fitness bug, you can monitor your heart rate with a piezo transducer. Of course, your smart phone or fitness tracker probably does that already. Don’t have one of those? We’ve got you covered there, too.

Filed under: Arduino Hacks, ARM

FleaFPGA + Arduino Uno = FleaFPGAUno

อาทิตย์, 11/22/2015 - 07:00

Some things are better together: me and my wife, peanut butter and jelly, and FPGAs and Arduino Unos. Veteran hacker [Valentin Angelovski] seems to agree: the FleaFPGA Uno is his latest creation that combines an FPGA (a Lattice MachX02 700HC) with an Arduino-compatible CPU.

It’s a step-up model from the origional FleaFPGA. With a few other components thrown in (such as a HDMI and composite video output and a WiFi option), you have a killer combination for experimenting with FPGAs or building an embedded system. That is because the Arduino part frees the FleaFPGA Uno from the breadboard: you can easily program, control and interface with the FPGA over a serial line or a wireless link using the Arduino IDE. There is even support for Arduino shields (albeit only 3.3V ones), making it even more expandable. This would be an awesome starting point for a retro gaming system, as many 8-bit consoles can be easily emulated in an FPGA. [Valentin] is currently selling the boards directly, and they are very reasonably priced at $50 or $60 for the WiFi version.

Filed under: Arduino Hacks, FPGA

DOE Announces a High Performance Computing Fortran Compiler Agreement

อาทิตย์, 11/22/2015 - 04:01

The U.S. Department of Energy’s National Nuclear Security Administration (NNSA) and its three national labs this week announced they have reached an agreement for an open-source Fortran front-end for Higher Performance Computing (HPC). The agreement is with IBM? Microsoft? Google? Nope, the agreement is with NVIDIA, a company known for making graphics cards for gamers.

The heart of a graphics card is the graphics processor unit (GPU) which is an extremely powerful computing engine. It’s actually got more raw horsepower than the computer CPU, although not as much as many claim. A number of years ago NVIDIA branched into providing compiler toolsets for their GPUs. The obvious goal is to drive sales. NVIDIA will use as a starting point their existing Fortran compiler and integrate it with the existing LLVM compiler infrastructure. That Fortran, it just keeps chugging along.

You can try out GPU programming on your Raspberry Pi. Yup! Even it has one, a Broadcom. Just follow the directions from Raspberry Pi Playground. You’re going to get your hands dirty with assembly language so this is not for the faint hearted. One of the big challenges with GPUs is exchanging data with them which gets into DMA processing. You could also take a look at [Pete Warden’s] work on using the Pi’s GPU.

Still wondering about the performance of CPU vs GPU? Here’s Adam Savage taking a look…

Filed under: news

Building A Better 3D Printed Gun

อาทิตย์, 11/22/2015 - 01:01

Back in 2013, [Cody Wilson] of Defense Distributed designed and built the world’s first completely 3D printed pistol. He called his gun the Liberator, after a World War II-era single-shot pistol designed to be cheap and easy to manufacture, easy to conceal, and for members of the French Resistance, ‘a great gun to obtain a better gun’.

[Cody]’s Liberator turned out to be a great gun to obtain two or three fewer fingers. Not only was this a single-shot pistol, it was a single barrel pistol; with each round fired requiring a new 3D printed barrel. Tests were carried out, explosions happened, and we couldn’t even get the thing to print. For all the media hubbub, for all the concerned legislators, the first 3D printed pistol was much ado about nothing.

3D printers are still an extremely interesting technology, and if history has proved one thing, it’s that engineers and tinkerers will keep building guns. Last week, [James Patrick] released his latest design for a working 3D printed gun. It still fires the .22lr of the Liberator, but this is a double action revolver, it won’t blow up, and if you drop it, it won’t discharge. It’s the little things that count.

[James]’ revolver is either a 6 or 8-shot revolver uses a pepper-box design, where the gun has multiple chambers and barrels in one gigantic cylinder. The double action design first rotates the cylinder to the next chamber, pulls back a striker loaded up with a firing pin nail, and (hopefully) fires a round. In the video below, [James] goes over the design of his action, and ends up showing off a few test firings of his newly designed gun.

What’s very interesting about this build is how closely the development of 3D printed firearms is following the development of historical firearms. First, we had guns that probably shouldn’t be fired, ever. Now, the technology for 3D printed guns is about up to 1830 or thereabouts. Give it a few more years and we’ll be up to 1911.

Disclaimer: if you live in the US and think this sort of thing should be illegal, contact your state representative and tell them you support a constitutional convention to remove the personal right to own and operate firearms. This right has been upheld many, many times by the judiciary, and a constitutional convention is the only way your wishes could be carried out. Your state representative probably doesn’t read Hackaday; there is no need to comment here. Let’s talk about engineering and technology instead.

Filed under: 3d Printer hacks, Featured

Hacklet 85: Alternative Audio Amplifiers

เสาร์, 11/21/2015 - 22:01

When you think of amplifiers, you’re probably thinking of audio or some big ‘ol power amps for radios. While interesting, there are some very interesting ‘alternative’ amplifiers floating around hackaday.io that are more than just power amps, and exceedingly useful, to boot.

[Ronald] bought an XMS amplifier a few years ago, and although it worked well, every time he changed the input, the loudness had to be toggled. One thing led to another, and he realized this amplifier had a four-channel audio processor that could be controlled by I2C. This was the beginning of his Network Amplifier.

Inside the box is a Raspberry Pi that controls a PT2314-based amplifier. Also included is a 2×16 character LCD, a few LEDs, switches, and a rotary encoder.  There was an Android app that controlled the amplifier, but this was discarded for a better looking web-based solution. Now [Ronald] has every audio source available over WiFi.

What if you want an audio amplifier without a speaker? Wait, what? That’s what [DeepSOIC] is doing with his experiments in ion wind loudspeakers.

‘Ion wind lifters’ have been around for decades now, mostly in the labs of slightly off-kilter people who believe this is the technology aliens are using to visit earth. Nevertheless, ion wind lifters produce an airflow, and if you make that wind variable, you get sound. Pretty cool, huh?

The amplifier for this project uses a tube to modulate kilovolt supply through the ion ‘blower’. Does it work? Sure does. [DeepSOIC] got a piece of 0.2 mm nichrome wire to discharge ions into the air, after which the ions drift into the second electrode. The result is sound, and the entire project is built deadbug style. It really doesn’t get cooler than this.


Continuing with the tube amp trend, [Marcel] built the cheapest little tube amp around.

The design of an audio tube amp is fairly simple business. First, you start with a big ‘ol transformer, and rectify the AC into DC. This gets fed into a preamp tube, and this is fed into a bigger power tube.

In about 50 years of development, tube designers had the technology down pat by the mid 1950s, and triode/pentode tubes were created. This allowed tube designers to condense two amplifier stages into a single tube. While this setup was usually used for cheap, toy-like electronics, you can still buy the ECL82 tube today.

[Marcel] took one of these tubes, added a rectifier tube, transformer, and big cap to create the simplest possible tube amp. Use it for guitars, use it for hi-fis, it’s all the same. It’s not going to sound great, but it is a very easy amp to build.

All of these interesting audio amplifier projects are curated on this new list! If you have a build that amplifies sound in an interesting way, don’t be shy, just drop [Adam] a message on Hackaday.io and he’ll add it. That’s it for this week’s Hacklet. As always, see you next week. Same hack time, same hack channel, bringing you the best of Hackaday.io!

Filed under: Hackaday Columns

Garbage can CNC Machine Build

เสาร์, 11/21/2015 - 19:01

Forget sourcing parts for your next project from some fancy neighborhood hardware store. If you really want to show your hacker chops, be like [HomoFaciens] and try a Dumpster dive for parts for a CNC machine build.

OK, we exaggerate a little – but only a little. Apart from the control electronics, almost everything in [HomoFacien]’s build could be found by the curb on bulk-waste pickup day. Particle board from a cast-off piece of flat-pack furniture, motors and gears from an old printer, and bits of steel strapping are all that’s needed for the frame of a serviceable CNC machine. This machine is even junkier than [HomoFacien]’s earlier build, which had a lot more store-bought parts. But the videos below show pretty impressive performance nonetheless.

Sure, this is a giant leap backwards for the state of the art in DIY CNC builds. but that’s the point – to show what can be accomplished with almost nothing, and that imagination and perseverance are more important for acceptable results than an expensive BOM.

With that in mind, we’re throwing down the gauntlet: can anyone build a CNC machine from cardboard and paperclips?

Filed under: cnc hacks