Building A Knife By Hand Is Just As Hard As You Think

June 7, 2018 by 47 Comments

Carl Sagan once said: “If you wish to make an apple pie from scratch, you must first invent the universe.” In other words, the term “scratch” is really a relative sort of thing. Did you grow the apples? Did you plant the wheat to make the flour? Where do you keep your windmill, incidentally? With Carl’s words in mind, we suppose we can’t say that [Flannagill] truly built this incredible knife from scratch, after all, he ordered the sheet steel on Amazon. But we think it’s close enough.

He was kind enough to document the epic build in fantastic detail, including (crucially), the missteps he made along the way. While none of the mistakes were big enough to derail the project, he mentions a few instances where he wasted time and money trying to take shortcuts. Even if making your own knives at home isn’t on your short list of summer projects, we’d wager there’s something in this build log you can learn from regardless.

So how does one build a knife? Slowly and methodically, if what [Flannagill] has written up is any indication. It started with a sketch of the knife on a piece of paper, the outline of which was then transferred to a piece of tool steel with nothing more exotic than a permanent marker. An angle grinder was then used to follow the outline and create the rough shape of the final knife.

From there, the process is done almost entirely with hand files. Here [Flannagill] gives one of his most important pieces of advice: don’t cheap out on the tools. He bought the cheapest set of files he could, and paid the price: he says it took up to 14 hours to complete just one side of the knife. Once he switched over to higher quality files, the rest of the work went much faster.

After filing and sanding the knife blank, it went into a charcoal fire to be hardened, followed by a total of 4 hours in a 200 C (~400 F) oven to heat temper it. Finally the handle pieces (which are officially known as “scales”) were attached, and finished with considerably less labor intensive woodworking methods. The final result is a gorgeous one of a kind specimen that [Flannagill] is rightly very proud of.

If you’re worried this process looks a bit too quick and easy for you, don’t worry. You can always go the [Bil Herd] route and make a forge out of your old sink if you’d rather start your apple pie a bit closer to the tree.

Ask Hackaday: What Is The Future Of Implanted Electronics?

June 7, 2018 by 139 Comments

Biohacking is the new frontier. In just a few years, millions of people will have implanted RFID chips under the skin between their thumb and index finger. Already, thousands of people in Sweden have chipped themselves to make their daily lives easier. With a tiny electronic implant, Swedish rail passengers can pay their train ticket, and it goes without saying how convenient opening an RFID lock is without having to pull out your wallet.

That said, embedding RFID chips under the skin has been around for decades; my thirteen-year-old cat has had a chip since he was a kitten. Despite being around for a very, very long time, modern-day cyborgs are rare. The fact that only thousands of people are using chips on a train is a newsworthy event. There simply aren’t many people who would find the convenience of opening locks with a wave of a hand worth the effort of getting chipped.

Why hasn’t the most popular example of biohacking caught on? Why aren’t more people getting chipped? Is it because no one wants to be branded with the Mark of the Beast? Are the reasons for a dearth of biohacking more subtle? That’s what we’re here to find out, so we’re asking you: what is the future of implanted electronics?

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Indiegogo Calls Time On The ZX Vega

June 7, 2018 by 15 Comments

It has been an exciting time to be a retro computer enthusiast in recent years, and the availability of affordable single board computers, systems-on-chip, and FPGAs have meant that retro hardware could be accurately reproduced or emulated. A host of classic micros have been reborn, to delight both the veterans who had the originals, and a new crop of devotees.

Today we have news of the impending demise of one of the higher-profile projects. The ZX Vega+ is a handheld Sinclair Spectrum console bearing the Sinclair name that came with an impeccable pedigree in that it had the support of the man himself. It seemed like a good proposition on the crowdfunding site Indiegogo, and when it made its debut there in early 2016 it attracted over half a million pounds worth of backing in short order. Things soon went sour though, with reports of a falling-out within Retro Computers, followed by multiple missed deadlines and promises undelivered over the last couple of years. With little sign of either the money or the console itself, it seems Indiegogo have now lost patience and will be sending in the debt collectors to recover what they can. Whether the backers will see any of their money is unclear.

It’s fair to say that the ZX Vega saga has been a tortuous and rather sordid one, out of which few players emerge smelling of roses. In a way though it is entirely in keeping with the spirit of the 8-bit era, as the period from the late 1970s onwards was littered with the financially bare corpses of dubiously run companies in the home computer industry. Meanwhile if you are hankering for a Vega it should be easy enough to create one for yourself, as Retro Computers Ltd admitted that under its skin was a copy of the FUSE software emulator. We suspect that most Hackaday readers could take a Raspberry Pi and a suitable LCD, pair them with a 3D-printed case and an 18650 cell, and be playing Manic Miner in no time. Far simpler than this convoluted Spectrum project!

Battleships Over BGP

June 7, 2018 by 14 Comments

The Border Gateway Protocol (BGP) is one of the foundations of the internet. It’s how the big routers that shift data around the Internet talk to each other, passing info on where they can send data to. It’s a simple protocol, with each router sending text messages that advertise the routes that they carry. The administrators of these routers create communities, each with an individual code, and this information is passed between routers. Most top-level ISPs don’t spread this data far, but [Ben Cox] realized that his ISP did. and that he could use this as an interesting way to transmit data over the Internet. What data to send? He decided to play battleships.

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Pocket Projector Uses Raspberry Pi

June 6, 2018 by 51 Comments

Who doesn’t want a pocket protector projector? Nothing will impress a date more than being able to whip out a PowerPoint presentation of your latest trip to the comic book convention. The key to [MickMake] build is the $100 DLP2000EVM evaluation module from Texas Instruments. This is an inexpensive light engine, and perfect for rolling your own projector. You can see the result in the video below.

If you don’t need compactness, you could drive the module with any Rasberry Pi or even a regular computer. But to get that pocket form factor, a Pi Zero W fits the bill. A custom PCB from [MickMake] lets the board fit in with the DLP module in a very small form factor.

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Stars Looking A Bit Dim? Throw Some Math At Them.

June 6, 2018 by 16 Comments

As the cost of high-resolution images sensors gets lower, and the availability of small and cheap single board computers skyrockets, we are starting to see more astrophotography projects than ever before. When you can put a $5 Raspberry Pi Zero and a decent webcam outside in a box to take autonomous pictures of the sky all night, why not give it a shot? But in doing so, many hackers are recognizing a fact well-known to traditional telescope jockeys: seeing a few stars is easy, seeing a lot of stars is another story entirely.

The problem is that stars are fairly dim; a problem compounded by the light pollution you get unless you’re out in a rural area. You can’t just brighten up the images either, as that only increases the noise in the image. A programmer always in search of a challenge, [Benedikt Bitterli] decided to take a shot at using software to improve astrophotography images. He documented the entire process, failures and all, on his blog for anyone else who might be curious about what it really takes to create the incredible images of the night sky we see in textbooks.

In principle it’s simple: just take a lot of pictures of the sky, stack them on top of each other, and identify which points of light are stars and which ones are noise artifacts. But of course the execution is considerably more difficult. For one thing, unless the camera was on a mount that was automatically tracking the sky, the stars will have slightly moved in each image. To help with this process, [Benedikt] used a navigational trick that humanity has relied on for millennia: mapping constellations. By comparing groupings of stars in each image, his software is able to accurately overlay each image.

But that’s only one part of the equation. In his post, [Benedikt] goes over the incredible amount of math that goes into identifying individual stars in the sea of noise you get when a digital image sensor looks into the black. You certainly don’t need to understand all the math to appreciate the final results, but it’s a fascinating read for those with an interest in computer vision concepts.

This kind of software is precisely what you want to pair with your 3D printed star tracker, or even better a Raspberry Pi sky monitoring station.

[Thanks to Helio Machado for the tip.]

Classifying Crystals With An SDR Dongle

June 6, 2018 by 4 Comments

When it comes to radio frequency oscillators, crystal controlled is the way to go when you want frequency precision. But not every slab of quartz in a tiny silver case is created equal, so crystals need to be characterized before using them. That’s generally a job for an oscilloscope, but if you’re clever, an SDR dongle can make a dandy crystal checker too.

The back story on [OM0ET]’s little hack is interesting, and one we hope to follow up on. The Slovakian ham is building what looks to be a pretty sophisticated homebrew single-sideband transceiver for the HF bands. Needed for such a rig are good intermediate frequency (IF) filters, which require matched sets of crystals. He wanted a quick and easy way to go through his collection of crystals and get a precise reading of the resonant frequency, so he turned to his cheap little RTL-SDR dongle. Plugged into a PC with SDRSharp running, the dongle’s antenna input is connected to the output of a simple one-transistor crystal oscillator. No schematics are given, but a look at the layout in the video below suggests it’s just a Colpitts oscillator. With the crystal under test plugged in, the oscillator produces a huge spike on the SDRSharp spectrum analyzer display, and [OM0ET] can quickly determine the center frequency. We’d suggest an attenuator to change the clipped plateau into a sharper peak, but other than that it worked like a charm, and he even found a few dud crystals with it.

Fascinated by the electromechanics of quartz crystals? We are too, which is why [Jenny]’s crystal oscillator primer is a good first stop for the curious.

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