Author: Bryan Cockfield

1853 Articles

The Math That Makes Computers Go, Built On A Tiny PCB

October 18, 2018 by 20 Comments

A computer is, at its core, just a bunch of transistors wired together. Once you have enough transistors on a board, though, one of the first layers of abstraction that arises is the Arithmetic Logic Unit. The ALU takes in two sets of data, performs a chosen math function, and outputs one data set as the result. It really is the core of what makes computers compute.

An ALU is built into modern processors, but that wasn’t always how it was done. If you’re looking to build a recreation of an early computer you may need a standalone, and that’s why [roelh] designed an ALU that fits in a square inch piece of circuit board using five multiplexer chips and two XOR chips.

One of the commonly used components for this purpose, the 74LS181 ALU, is not in production anymore. [roelh’s] ALU is intended to be a small footprint replacement of sorts, and can perform seven functions: ADD, SUB, XOR, XNOR, AND, OR, A, B, and NOT A. The small footprint for the design is a constraint of our recent contest: Return of the Square Inch Project. Of course, this meant extra design challenges, such as needing to move the carry in and carry out lines to a separate header because there wasn’t enough space on one edge.

Exploring the theory behind an ALU isn’t just for people building retrocomputers. It is integral to gaining an intuitive understanding of how all computers work. Everyone should consider looking under the hood by walking through the nand2tetris course which uses simulation to build from a NAND gate all the way up to a functioning computer based on The Elements of Computing Science textbook.

If you’re a homebrew computer builder, it might be worthwhile to use one of these ALUs rather than designing your own. Of course, if building components from scratch is your thing we definitely understand that motivation as well.

Popup Notification Dinosaur

October 18, 2018 by 1 Comment

There’s a lot going on our virtual spaces, and anyone with a smart phone can attest to this fact. There are pop-up notifications for everything you can imagine, and sometimes it’s possible for the one really important notification to get lost in a sea of minutiae. To really make sure you don’t miss that one important notification, you can offload that task to your own personal dinosaur.

The 3D-printed dinosaur has a rack-and-pinion gear set that allows it to extend upwards when commanded. It also has a set of LEDs for eyes that turn on when it pops up. The two servos and LEDs are controlled by a small Arduino in the base of the dinosaur. This Arduino can be programmed to activate the dinosaur whenver you like, for an email from a specific person, a reply to a comment on Reddit, or an incoming phone call to name a few examples. Be sure to check out the video below the break.

With this dinosaur on your desk, it’s not likely you’ll miss its activation. If you’d like something that has the same function but with less movement and more lights, there’s also a notification 3D cube made out of LEDs that’s sure to catch your eye as well. Continue reading “Popup Notification Dinosaur” →

3D Printing, Halloween Style

October 17, 2018 by 3 Comments

The wonders of 3D printing don’t stop coming. Whether it’s printing tools on the International Space Station, printing houses out of concrete, or just making spare parts for a child’s toy, there’s virtually nothing you can’t get done with the right 3D printer, including spicing up your Halloween decorations.

Not only is this pumpkin a great-looking decoration for the season on its own, but it can also transform into a rather unsettling spider as well for a little bit of traditional Halloween surprise. The print is seven parts, which all snap into place and fold together with a set of ball-and-socket joints. While it doesn’t have any automatic opening and closing from a set of servos, perhaps we will see someone come up with a motion-activated pumpkin spider transformer that will shock all the trick-or-treaters at the end of this month.

It’s not too late to get one for yourself, either. The files are available on Thingiverse or through the project site. And we’ve seen plenty of other Halloween hacks and projects throughout the years too if you’re looking for other ideas, like the recent candy machine game, a rather surprising flying human head, or this terrifying robot.

Flamethrower Gets Update, Retains Some Sketchiness

October 17, 2018 by 16 Comments

Part of what makes flamethrowers fun is their inherent danger. This is what makes a lot of things fun, though, from snowboarding to skydiving to motorcycle riding. As with all of these sensible hobbies, though, it’s important to take as much unnecessary risk out of the activity as possible to make sure you’re around as long as possible to enjoy your chosen activity. With that in mind, [Stephen] decided to make some improvements on his classic wrist-mounted flamethrower.

To start, he ditched the heavy lead-acid battery that powered the contraption in favor of a smaller 5 V battery. In fact, the entire build is much more compact and efficient. He was also able to use the same battery to run a tiny taser that acts as an ignition source for the flamethrower’s fuel. The fuel itself is butane, and the modified flamethrower is able to launch flames much further than the original due to improvements in the fuel delivery system. These improvements also include “Finding a way to prevent butane droplets from lighting and landing on [his] hand” which seems like a necessary feature as well.

The entire build now is very well refined and professional-looking, which is also a major improvement from the first version. It’s also worth watching the video after the break as well, which includes a minor run-in with the New York City fire marshal. And, it still retains some of the danger and all of the fun of the original builds which is something we always like to see.

Continue reading “Flamethrower Gets Update, Retains Some Sketchiness” →

Modular Violin Takes A Bow

October 16, 2018 by 10 Comments

They say the only difference between a violin and a fiddle is the way you play it. If that’s so, this modular violin will need a new name, since it can be broken apart and changed in ways that make it sound completely different, all within a few minutes.

The fiddle is the work of [David Perry] and has 3D printed body, neck, pegbox, and bridge. While it might seem useful on the surface as a way to get less expensive instruments out in the world where virtually anyone has access to them, the real interesting qualities are shown when [David] starts playing all of the different versions he’s created. The sound changes in noticeable ways depending on the style of print, type of plastic used, and many other qualities.

Of course you will need a bow, strings, pegs, and a fingerboard, but the rest is all available if you have a 3D printer around. If you’re already a skilled violinist this could be a very affordable way to experiment with new sounds. It’s not the first time we’ve seen 3D printed violins, but it is the first time we’ve seen them designed specifically to alter the way they sound rather than their physical characteristics. If you want to make your own, all of the .stl files are available on the project’s site.

Continue reading “Modular Violin Takes A Bow” →

Construction Cranes Versus Hurricanes

October 15, 2018 by 14 Comments

When engineers are designing buildings, bridges, or other large construction projects, a lot of thought is given to the environment. Some of these considerations might seem obvious, like designing a skyscraper in San Francisco to tolerate earthquakes, building a stadium in New York City to hold up not only its own weight but the weight of several feet of snow on the roof, or constructing bridges in any coastal area to be able to tolerate salt spray. Not everything is this straightforward, though. Not only do the structures themselves have to tolerate the environmental conditions they are in, but the equipment that is used to build them must tolerate these conditions as well, specifically the large cranes that are often semi-permanently attached to their construction sites.

Perhaps the most extreme example of this in recent memory was during Typhoon Manghut as it hit Hong Kong. There were several large construction cranes that didn’t fare too well with the high winds. At least one toppled as a result and catching the free-spinning of another on video is more than enough to make you gasp. Other videos of construction cranes surfaced from this typhoon showing some concerning, but surprisingly well-designed, emergency operation of the same type of crane.

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New Controller For Retro Console

October 12, 2018 by 4 Comments

In the world of retro gaming, when using emulators and non-native hardware it’s pretty common to use whatever USB controller happens to be available. This allows us to get a nostalgic look while using a  configurable controller. One thing that isn’t as common is using the original hardware while still finding a way to adapt a modern controller to an old console. This is exactly what you need though, when you’re retro gaming on a platform with notoriously terrible controllers.

[Scott] enjoys his Atari 5200 but the non-centering and generically terrible joystick wasn’t well received even in the early 80s when the console was in its prime. He decided that using a Dual Shock controller from a Playstation 2 would provide a much better gaming experience, and set about building an adapter. He found that in a way the Dual Shock controller was an almost perfect pairing for the Atari because it has two analog control sticks built-in already. There’s also an array of information on pairing the Dual Shock controller with AVR microcontrollers, so he wouldn’t have to reinvent the wheel. From there, it was just a matter of pairing communications protocols between the two pieces of hardware.

The project page goes into quite a bit of detail on SPI communication protocols and the needs of both the Atari and the Playstation controller. If you’re a retro gaming fan, really into communication protocols, or have always had a love-hate relationship with your Atari because the controllers were just that bad, it’s worth checking out. If this is too much, though, there are other ways to get that Atari nostalgia.

Thanks to [Baldpower] for the tip!

Continue reading “New Controller For Retro Console” →