Hacking Shelters And Swimming Pools

July 18, 2019 by Al Williams 44 Comments

How would you survive in a war-torn country, where bombs could potentially fall from the sky with only very short notice? And what if the bomb in question were The Bomb — a nuclear weapon? This concern is thankfully distant for most of us, but it wasn’t always so. Only 75 years ago, bombs were raining down on England, and until much more recently the threat of global thermonuclear war was encouraging school kids to “duck and cover”. How do you protect people in these situations?

The answers, naturally, depend on the conditions at hand. In Britain before the war, money was scarce and many houses didn’t have basements or yards that were large enough to build a family-sized bomb shelter in, and they had to improvise. In Cold War America, building bomb shelters ended up as a boon for the swimming pool construction industry. In both cases, bomb shelters proved to be a test of engineering ingenuity and DIY gumption, attempting to save lives in the face of difficult-to-quantify danger from above.

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Art Meets Science In The Cold Wastelands Of Iceland

July 17, 2019 by Pat Whetman 13 Comments

Although Iceland is now a popular destination for the day-tripping selfie-seeking Instagrammer who rents a 4×4, drives it off road onto delicate ecosystems and then videos the ensuing rescue when the cops arrive, there are still some genuine photographers prepared to put a huge amount of time and effort into their art. [Dheera Venkatraman] is one of the latter and produces composite photos using a relatively low resolution thermal camera and DIY pan and tilt rig.

Whilst we don’t have the exact details, we think that, since the Seek Reveal Pro camera used has a resolution of 320 x 240, [Dheera] would have had to take at least 20 photos for each panoramic shot. In post processing, the shots were meticulously recombined into stunning landscape photos which are a real inspiration to anybody interested in photography.

If you do go to Iceland you might find the traditional food a little challenging to those not raised upon it, nor would you go there for a stag night as beer is eyewateringly expensive. But if you enjoy uninhabitable, desolate, dramatic landscapes there is a huge range of possibilities for the photographer from rugged, frozen lava flows to extra terrestrial ‘Martian’ crater-scapes, if you know where to find them.

[Dheera’s] blog contains some more information about his Iceland photography and there’s a Github repsoitory too. And if you cant afford a $699 Seek Reveal Pro, maybe try building one yourself.

3D Printed Prosthesis Reads Your Mind, Sees With Its Hand

July 17, 2019 by Erin Pinheiro 4 Comments

Hobbyist electronics and robotics are getting cheaper and easier to build as time moves on, and one advantage of that is the possibility of affordable prosthetics. A great example is this transhumeral prosthesis from [Duy], his entry for this year’s Hackaday Prize.

With ten degrees of freedom, including individual fingers, two axes for the thumb and enough wrist movement for the hand to wave with, this is already a pretty impressive robotics build in and of itself. The features don’t stop there however. The entire prosthesis is modular and can be used in different configurations, and it’s all 3D printed for ease of customization and manufacturing. Along with the myoelectric sensor which is how these prostheses are usually controlled, [Duy] also designed the hand to be controlled with computer vision and brain-controlled interfaces.

The palm of the hand has a camera embedded in it, and by passing that feed through CV software the hand can recognize and track objects the user moves it close to. This makes it easier to grab onto them, since the different gripping patterns required for each object can be programmed into the Raspberry Pi controlling the actuators. Because the alpha-wave BCI may not offer enough discernment for a full range of movement of each finger, this is where computer aid can help the prosthesis feel more natural to the user.

We’ve seen a fair amount of creative custom prostheses here, like this one which uses AI to allow the user to play music with it, and this one which gives its user a tattoo machine for an appendage.

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How Not To Get Paid For Open Source Work

July 5, 2019 by Donald Papp 47 Comments

[Avi Press] recently made a Medium post sharing his thoughts on a failed effort to allow for paid users of an open source project. [Avi] is the author of Toodles, a tool to help organize and manage TODO items in software development. Toodles enjoyed unexpected popularity, and some of its users were large organizations. It seemed that Toodles was of value to people who could afford to pay, and they might even be willing to do so if [Avi] provided a way for them to do it. It turned out that the monetizing process was far from simple, and he ultimately wasn’t successful.

Before he even started, [Avi] thought carefully about things and found that even basic and preliminary questions were difficult to answer, such as:

How many people were actually using the software on a regular basis? Were they gaining quantifiable value from it?
What exactly would someone be buying? How would they pay, and how would it get delivered to them?
How could companies be charged for the tool while still offering it freely to individuals?
Is it even ethical to accept money for a project to which others have contributed? How could money be shared with contributors? How to fairly decide who gets how much?

In short, [Avi] discovered that much of the data he felt he needed in order to make these decisions didn’t exist, wasn’t easily accessible, or couldn’t be reliably measured. His experiment in adding a license and payment system (which always seemed to need more work than it should) yielded no fruit, as there were zero paid users anyway.

Regardless of whether “difficulty in shoehorning a paid license system into an open source project” should be filed under “Feature, not Bug” [Avi] does thoughtfully present the issues he encountered. Open source and getting paid are not necessarily mutually exclusive. Octoprint is one example of an open source project that eventually navigated these waters, but that doesn’t mean it was easy, nor does it mean there are established tools and processes.

Ask Hackaday: How Can You Build For A Ten Millennia Lifespan?

July 1, 2019 by Al Williams 97 Comments

There’s been a lot of news lately about the Long Now Foundation and Jeff Bezos spending $42 million or so on a giant mechanical clock that is supposed to run for 10,000 years. We aren’t sure we really agree that it is truly a 10,000 year clock because it draws energy — in part — from people visiting it. As far as we can tell, inventor Danny Hills has made the clock to hoard energy from several sources and occasionally chime when it has enough energy, so we aren’t sure how it truly sustains itself. However, it did lead us to an interesting question: how could you design something that really worked for 10,000 years?

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Connecting New York City To The Backbone: Meet NYC’s Mesh Network

June 30, 2019 by Maya Posch 25 Comments

Access to fast and affordable internet is a big issue in the USA, even in a major metropolis such as New York City. Amidst a cartel of ISPs who simply will not deliver, a group of NYC inhabitants first took it upon themselves to ease this situation by setting up their own mesh-based internet connections way back in 2013. Now they will be installing a new Supernode to take the installation base far beyond the current 300 buildings serviced.

As a community project, NYC Mesh is run as a non-profit organization, with its community members supporting the effort through donations, along with partnerships with businesses. Its router hardware consists out of off-the-shelf equipment (with a focus on the Ubiquiti NanoStation NSM5) that get flashed with custom firmware containing the mesh routing functionality.

As this article by Vice mentions, NYC Mesh is one of 750 community-led broadband projects in the US. Many of those use more traditional fixed wiring with distribution lines, but NYC Mesh focuses fully on wireless (WiFi) links with wireless mesh networking. This has the obvious benefit that given enough bandwidth on the Supernodes that hook into the Internet exchange points (IXP) and an efficient mesh routing protocol, it’s quick and easy to hook up new clients and expand the network.

The obvious downsides of using WiFi and RF in general is that they are not immune to outside influences, such as weather (rain), RF interference (including from other WiFi stations) and of course fairly limited range if there’s no direct line of sight. In a densely populated city such as NYC this is not much of an issue, with short hops between roof tops.

Tic-Tac-Toe, In TTL

June 29, 2019 by Jenny List 15 Comments

We’ll all be familiar with Tic-Tac-Toe, or Noughts and Crosses, a childhood pencil-and-paper diversion which has formed the basis of many a coding exercise. It’s an easy enough task to implement in software, but how many of us have seen it done in hardware alone? That’s just what [Warren Toomey] has done using TTL chips, and his method makes for a surprisingly simple circuit.

At its heart is an 8 kB ROM that contains precomputed move sequences that are selected via an address composed of the game states for both player and machine. A series of flip-flops control and buttons to make the board, and a 555 provides a clock.

The technique of using a ROM to replace complex logic is a very powerful one that is facilitated by the low price of relatively large devices that would once have been unaffordable. We’ve seen the technique used elsewhere, including as an ALU in a TTL CPU, and even for an entire CPU in its own right.

You can see the result in operation in the video below the break, and should you wish to have a go for yourself all the relevant information can be found in a GitHub repository.

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