Blacksmithing For The Uninitiated: Curves And Rings

July 18, 2019 by 9 Comments

You know the funny looking side of the anvil? That’s where the best curves come from. It’s called the anvil horn and is the blacksmith’s friend when bending steel and shaping it into curves.

The principle of bending a piece of steel stock is very easy to understand. Heat it up to temperature, and hammer it over a curved profile to the intended shape. A gentler touch is required than when you are shaping metal. That’s because the intent is to bend the metal rather than deform. Let’s take a look!

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Torturing An Instrumented Dive Watch, For Science

July 18, 2019 by 24 Comments

The Internet is a wild and wooly place where people can spout off about anything with impunity. If you sound like you know what you’re talking about and throw around a few bits of the appropriate jargon, chances are good that somebody out there will believe whatever you’re selling.

Case in point: those that purport that watches rated for 300-meter dives will leak if you wiggle them around too much in the shower. Seems preposterous, but rather than just dismiss the claim, [Kristopher Marciniak] chose to disprove it with a tiny wireless pressure sensor stuffed into a dive watch case. The idea occurred to him when his gaze fell across an ESP-01 module next to a watch on his bench. Figuring the two needed to get together, he ordered a BMP280 pressure sensor board, tiny enough itself to fit anywhere. Teamed up with a small LiPo pack, everything was stuffed into an Invicta dive watch case. A little code was added to log the temperature and pressure and transmit the results over WiFi, and [Kristopher] was off to torture test his setup.

The first interesting result is how exquisitely sensitive the sensor is, and how much a small change in temperature can affect the pressure inside the case. The watch took a simulated dive to 70 meters in a pressure vessel, which only increased the internal pressure marginally, and took a skin-flaying shower with a 2300-PSI (16 MPa) pressure washer, also with minimal impact. The video below shows the results, but the take-home message is that a dive watch that leaks in the shower isn’t much of a dive watch.

Hats off to [Kristopher] for doing the work here. We always love citizen science efforts such as this, whether it’s hardware-free radio astronomy or sampling whale snot with a drone.

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The Arduboy, Ported To Desktop And Back Again

July 18, 2019 by 21 Comments

A neat little hacker project that’s flying off the workbenches recently is the Arduboy. This tiny game console looks like a miniaturized version of the O.G. Game Boy, but it is explicitly designed to be hacked. It’s basically an Arduino board with a display and a few buttons, anyway.

[rv6502] got their hands on an Arduboy and realized that while there were some 3D games, there was nothing that had filled polygons, or really anything resembling a modern 3D engine. This had to be rectified, and the result is pretty close to Star Fox on a microcontroller.

This project began with a simple test on the Arduboy to see if it would be even possible to render 3D objects at any reasonable speed. This test was just a rotating cube, and everything looked good. Then began a long process of figuring out how fast the engine could go, what kind of display would suit the OLED best, and how to interact in a 3D world with limited controls.

Considering this is a fairly significant engineering project, the fastest way to produce code isn’t to debug code on a microcontroller. This project demanded a native PC port, so all the testing could happen on the PC without having to program the Flash every time. That allowed [rv] to throw out the Arduino IDE and USB library; if you’re writing everything on a PC and only uploading a hex file to a microcontroller at the end, you simply don’t need it.

One of the significant advances of the graphics capability of the Arduboy comes from exploring the addressing modes of the OLED. By default, the display is in a ‘horizontal mode’ which works for 2D blitting, but not for rasterizing polygons. The ‘vertical addressing mode’, on the other hand, allows for a block of memory, 8 x 128 bytes, that maps directly to the display. Shove those bytes over, and there’s no math necessary to display an image.

This is, simply, one of the best software development builds we’ve seen. It’s full of clever tricks (like simply not doing math if you’ll never need the result) and stuffing animations into far fewer bytes than you would expect. You can check out the demo video below.

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BornHack Tease Us With Their Badge

July 17, 2019 by No comments

Every August for the past four years, there has been a summer hacker camp on the Danish island of Bornholm, that may be a relatively new kid on the block but is slowly evolving into one of the summer’s essential stop-offs. This year for the first time they are moving to a larger site in an easier-to-reach part of the country, and in the usual build-up to the event they have released a teaser image of their badge.

Of course, you will want to know a little more about it than the picture can convey, so the BornHack folks were kind enough to give us a few more details. At its heart is a Silicon Labs Happy Gecko EFM32HG322F64G microcontroller, the same 25 MHz ultra-low-power ARM Cortex M0+ part that has featured in the previous BornHack offerings. Power comes from a pair of AA cells, and it sports a 240 x 240 pixel colour IPS display and an SD card holder. Connectivity is via USB and an infra-red interface for badge-to-badge communication, and human interface is via a mini joystick switch. Finally, it has a six-way v1.69bis Shitty Addon connector.

By some standards this is a relatively modest offering, but by using an evolution of their hardware from previous years as well as the same proven Geckoboot bootloader they are far more likely to deliver a satisfactory user experience than had they opted for a more ambitious design. We’ll be attending the camp, so we’ll report on the finished article once we have it.

BornHack will run from the 8th to the 15th of August, on the Danish island of Funen. There are a range of tickets still available, from single day visits to the whole week for 1200 DKK (about €160, or $181). Compared to some other events on our community’s calendar, we think that represents a bargain.

Art Meets Science In The Cold Wastelands Of Iceland

July 17, 2019 by 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.

High-Tech Alms Collection With The ESP32

July 17, 2019 by 2 Comments

In an ideal world, shop space, tools, and components would be free. But until we get to that Star Trek utopia, hackerspaces will have to rely on donations from the community to help stay afloat. While asking for money, at least you can have some fun with it if you design and build an Internet-connected donation box.

Or at least that’s how [Goran Mahovlic] handled it for the Radiona hackerspace in Zagreb, Croatia. Not content with just cutting a slit in the top of a shoe box, he came up with a physical donation system that’s not only more informative for those donating, but more organized for those collecting the funds.

The key is a arcade-style programmable coin acceptor from SparkFun. When connected to a microcontroller, this allows the box to keep a running tally on how much money has been inserted. With the use of a RFM96 LoRa module, it can even report on the current haul while remaining mobile; perfect for when the hackerspace has events outside of their home base.

But counting quarters is hardly a task befitting a powerful microcontroller like the ESP32. So [Goran] gave the chip something to do in its spare time by adding a couple of buttons and an LCD. This allows the user to scroll through a list of various projects that are looking for donations, and decide which one they want to financially support. When the donation box counts how much money has been inserted, it records which project its been earmarked for.

Of course, if you’d rather the free market do its thing, we’ve seen this same coin acceptor used to build a locker-sized vending machine. Or if you’re feeling crafty, you could always try your hand at building one with cardboard.

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A Fruity Approach To CNC Design

July 17, 2019 by 8 Comments

[Frank Howarth] found himself in need of a lamp for his dining room. Being of the maker persuasion, store-bought simply wouldn’t do. With a serious wood shop at his disposal, [Frank] took a trip down to the supermarket for inspiration.

Having picked out a particularly well-formed starfruit for his project, [Frank] didn’t want to spend an inordinately long time attempting to recreate the organic lumps and bumps in modelling software, Instead, Meshroom was used to create a model through photogrammetry. After several failed attempts, success was achieved by using a textured rotating table as a background, with the starfruit painted in matte grey and a final dusting of black speckle. This gave the software enough visual cues to accurately model the fruit’s geometry.

With a 3D model to hand, Fusion Slicer was then used to generate a model that could be constructed out of flat lasercut pieces. The cutting outlines were then generated and passed to Rhino for final tweaking. With everything ready, parts were cut out of plywood and a small mockup of a potential lamp design was created. [Frank] is currently workshopping the design with the inhabitants of the dining room, prior to the final build.

Photogrammetry and modern CAD tools make working with natural forms quick and easy. We’ve also seen the technology used for other purposes too, with [Eric Strebel] providing a great example on how to use it for reverse engineering.

The starfruit tag on Hackaday is pretty sparse, so if you’ve got a project, let us know. Video after the break.

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