Turn That Old Tablet Into A Sub-$100 Linux Laptop

November 5, 2016 by Jenny List 43 Comments

Tiny laptops have always been devices that promise so much, yet fail somehow to deliver. From the Atari Portfolio palmtops through to the recent crop of netbooks they have been either eye-wateringly expensive if they are any good, or so compromised by their size constraints as to be next-to-useless. We’ve seen DOS, EPOC, Windows, WinCE, Palm OS, Linux distros and more in tiny form factors over the years, yet few have made a significant mark.

The prospect of a “proper” computer in your hand isn’t something to abandon just yet though. We are now reaching the point at which the previous generation of higher-end Android tablets are both acceptably powerful and sufficiently numerous as to be available at a very reasonable price. Perhaps these can provide the tiny laptop seeker with a basis for something useful. [NODE] certainly thinks so, because he’s produced a nice little Ubuntu laptop using a second-hand Nexus 7 tablet and a Bluetooth keyboard case. Android is replaced with an Ubuntu image, and a cardboard cut-out display bezel is held in place with magnetic strips. A step-by-step guide has been put up to help others interested in following the same path.

This is not the most amazing of hardware hacks, in that it involves mostly off-the-shelf items and a piece of software. However it’s worth a look because it does provide a route to a very acceptable little Linux laptop for an extremely reasonable price. One concern is that the Ubuntu version seems not to be a recent one, however we’re sure readers will point at any newer distribution builds in the comments. If you fancy a look at the finished laptop he’s posted a video which we’ve included below the break.

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Brazing Aluminum

November 4, 2016 by Jenny List 80 Comments

Where do you stand on one of the eternal questions of metalwork: brazing, or welding? As your Hackaday writer, and the daughter of a blacksmith, it’s very much on the welding side here. Brazed joints can come apart too easily, which is why in the territory this is being written in at least, they are not permitted for the yearly vehicle roadworthiness test. If you’ve ever had to remove a brazed-on patch with an angle grinder, you’ll know which one you’d trust in a crisis.

What if the metal in question is aluminum? [George Graves] sends us a link to a forum discussion on the subject from a few years ago, and to a YouTube video which we’ve embedded below the break. Miracle brazing rods claim astounding toughness, but the world divides into those who favour TIG’s strength versus those who point to brazing’s penetration far between the surfaces of the metal to be joined. Having experimented with them a while back, we’ll admit that it’s true that aluminum brazing rods join broken parts impressively well. But yet again you won’t see this Hackaday writer riding a bike that wasn’t welded with the trusty TIG torch.

Take a look at the video, and see what you think. Even if it’s not a joint you’d stake your life on it’s still a technique that’s a useful addition to your workshop arsenal.

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Probably The Simplest Electronic Temperature Controlled Soldering Iron

November 4, 2016 by Jenny List 29 Comments

We’re all used to temperature controlled soldering irons, and most of us will have one in some form or other as our soldering tool of choice. In many cases our irons will be microprocessor controlled, with thermocouples, LCD displays, and other technological magic to make the perfect soldering tool.

All this technology is very impressive, but how simply can a temperature controlled iron be made? If you’re of an older generation you might point to irons with bimetallic or magnetic temperature regulation of course, so let’s rephrase the question. How simply can an electronic temperature controlled soldering iron be made? [Bestonic lab] might just have the answer, because he’s posted a YouTube video showing an extremely simple temperature controlled iron. It’s not the most elegant of solutions, but it does the job demanded of it, and all for a very low parts count.

He’s taken a ceramic housing from a redundant fuse holder, and mounted it on a metal frame to make a basic soldering iron holder into which the tip of his unregulated iron fits. To the ceramic he’s fitted a thermistor, which sits in the gate bias circuit of a MOSFET. The MOSFET in turn operates a relay which supplies mains power to the iron.

Temperature regulation comes as the iron heats the ceramic to the point at which the thermistor changes the MOSFET and relay state, at which point (with the iron power cut) it cools until the MOSFET flips again and restarts the process. You may have spotted a flaw in that it requires the iron to be in the holder to work, though we suspect in practice the thermal inertia of the ceramic will be enough for regulation to be reasonably maintained so long as the iron is returned to its holder between joints. Nobody is claiming that this temperature controlled iron is on a par with its expensive commercial cousins, instead it represents a very neat hack to conjure a useful tool from very few components. And we like that. Take a look at the full video below the break.

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VR Feels More Real With Leap Motion And This Rotation Sensor

November 4, 2016 by Jenny List 20 Comments

You could have said this at any time in the last couple of decades: the world of virtual reality peripherals does not yet feel as though it has fulfilled its potential. From the Amiga-powered Virtuality headsets and nausea-inducing Nintendo Virtual Boy of the 1990s to today’s crop of advanced headsets and peripherals, there has always been a sense that we’re not quite there yet. Moments at which the shortcomings of the hardware intrude into the virtual world may be less frequent with the latest products, but still the goal of virtual world immersion seems elusive at times.

One of the more interesting peripherals on the market today is the Leap Motion controller. This is a USB device containing infra-red illumination and cameras which provide enough resolution for its software to accurately calculate the position of a user’s hands and fingers in three-dimensional space. This ability to track finger movement gives it the function of a controller for really complex interactions with and manipulations of objects in virtual worlds.

Even the Leap Motion has its shortcomings though, moments at which it ceases to be able to track. Rotating your hand, as you might for instance when aiming a virtual in-game weapon, confuses it. This led [Florian Maurer] to seek his own solution, and he’s come up with a hand peripheral containing a rotation sensor.

Inspired by a movie prop from the film Ender’s Game, it is a 3D-printed device that clips onto the palm of his hand between thumb and index finger. It contains both an Arduino Pro Micro and a bno055 rotation sensor, plus a couple of buttons for in-game actions such as triggers. It solves the problem with the Leap Motion’s rotation detection, and does not impede hand movement so much that he can’t also use his keyboard and mouse while wearing it. Sadly he does not yet seem to have posted any code, but he does treat us to a video demonstration which we’ve posted below the break.

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The Comic Book World Of Capacitor Marketing

November 3, 2016 by Jenny List 69 Comments

The Economist is an interesting publication, a British weekly newspaper that looks for all the world like a magazine, and contains pithy insights into world politics and economic movements. It’s one of those rare print news publications that manages to deliver fresh insights even to hardened web news junkies despite its weekly publication date.

It was typical then of their wide-ranging coverage of world industries to publish a piece recently on the world of supercapacitors, with particular focus on Estonia’s Skeleton Technologies. This is an exciting field in which the products are inching their way towards energy density parity with conventional batteries, and news of new manufacturing facilities coming online should be of interest to many Hackaday readers.

Exciting though it may be it was not the news of a new capacitor plant in Germany that provided the impetus for this piece. Instead it was the language used by the Economist writer delicately skirting the distinction between the words “Supercapacitor” and “Ultracapacitor”. Images of flying crimefighters in brightly coloured capes spring instantly to mind, as Captain Ultra and Superman battle an arch-villain who is no doubt idly bouncing a piece of burning Kryptonite against the wall in readiness for the final denouement.

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HFSat And The All-HF Amateur Radio Satellite Transponder

November 3, 2016 by Jenny List 17 Comments

One facet of the diverse pursuit that is amateur radio involves the use of amateur radio satellites. These have a long history stretching back to the years shortly after the first space launches, and have been launched as “piggy-back” craft using spare capacity on government and commercial launches.

Though a diverse range of payloads have been carried by these satellites over the years, the majority of amateur radio satellites have featured transponders working in the VHF and UHF spectrum. Most often their links have used the 2m (144 MHz) and 70cm (430MHz) bands. A few have had downlinks in the 10m (28MHz) band, but this has been as far as they have ventured into the HF spectrum.

A new cubesat designed and built by trainees at the US Naval Academy promises to change all that, because it will feature an all-HF transponder with a 15m (21MHz) uplink and a 10m downlink. To that end it will carry a full size 10m wire dipole antenna. The 30KHz wide transponder is an inverting design intended to cancel out the effects of Doppler shift. In their write-up they provide a fascinating description of many aspects of cubesat design, one which should be of significant interest beyond the world of amateur radio.

If the subject of amateur radio in space interests you, have a look at our series on the matter, first covering the OSCAR satellites, and then our recent feature on its use in manned missions.

[via Southgate ARC]

Computer Emulation In The Manner Of A Turducken

November 2, 2016 by Jenny List 39 Comments

If you come from somewhere with a tradition of eating a meal of roast turkey or goose to celebrate Christmas, Thanksgiving, or other holidays, then maybe you’ve encountered the three-bird roast, or Turducken. A deboned duck is stuffed with a deboned chicken, and in turn the combination is stuffed into a turkey All the gaps are filled with sausage meat stuffing, and the resulting combination is roasted for a serious meat-fest. Vegetarians, please look away.

It’s something of an excess of poultry, but the three-bird roast is a delicacy that definitely works. We’re not so sure about the link that prompted this journey into celebration poultry dishes by reminding us of a turducken, but we’ll leave the verdict to you the reader. Someone has created an unholy turducken-style chain of emulators that delivers a Sinclair ZX Spectrum on a Linux machine via Windows, DOS, and the Commodore 64. If it had its own word like the poultry dish it might be a Linwindoscomtrum, but let’s not go there.

The linwincomtrum in all its glory. — The linwindoscomtrum in all its glory.

So how have they done it? First, they took Lubuntu, and installed WINE. (OK, Wine Is Not an Emulator, we know that, but go with the story for a moment) Then they installed DOSBox under WINE for a DOS command prompt, and ran no$C64, a Commodore 64 emulator. On that they ran the c642spec Sinclair ZX Spectrum emulator, and finally arrived in a ZX BASIC prompt.

The author does make the point at the start of the write-up that it’s a waste of ten minutes, but even though the result is an overly complex way to slowly emulate an archaic home computer on a modern one we’ll still give them ten out of ten for the effort.

Incidentally, the author does not identify themself and there is little clue in the form of the rest of the site to identify them, so unusually for a Hackaday piece we can not give credit where it is due. We do however salute the anonymous emulator pilot for their glorious folly.

If the ZX piques your interest, we’ve featured a coding tutorial for the rubber-keyed British micro in the past, as well as a later one having a tape-drive-ectomy, and of course the hellzxschreiber amateur radio Hellschreiber receiver.

Via Hacker News. ZX Spectrum image: Bill Bertram [CC BY-SA 2.5], via Wikimedia Commons.