An electric eraser built into a mechanical pencil

Power Up Your Pencil With The 30,000 RPM Erase-O-Matic

June 2, 2022 by 20 Comments

There are some inventions that look completely pointless to the untrained eye: who would ever need a motorized garbage can, an electric pencil sharpener or a battery-powered eraser? Quite often, it turns out that there is some niche use case where such tools make complete sense, as is the case for motorized erasers. Having a tiny piece of rubber spinning at high speed gives artists and drafters a way to very precisely delete or lighten bits of their drawing, something that’s nearly impossible to do with a regular eraser.

[Franklinstein] however decided to design a high-speed eraser integrated into a mechanical pencil that brings the whole concept straight back to the pointless category, although not without showing off his advanced engineering skills. The Erase-O-Matic contains a miniature electric motor sourced from a quadcopter, together with an ultra-small lithium-ion battery and a power switch. The spinning bit is held by a tiny bearing, with the whole setup covered by a machined aluminium housing.

Tests with a laser tachometer show a rotational speed of about 30,000 RPM, which is almost three times as fast as a commercial electric eraser. And although it has very good erasing performance, it also wears out its tip in a few seconds, so a bit less speed could actually make this device more useful. If you’re planning to build one of these yourself, you might want to first read our primer on small DC motors.

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LED Heart Keeps Tabs On Your RuneScape Character

June 2, 2022 by 8 Comments

The MMORPG RuneScape holds a special place in the hearts of those who played it in the early 2000s. Sure it might seem exceptionally quaint by modern standards, but at the time it was groundbreaking stuff. Plus you could play it for free, which certainly helped get people onboard. While there’s a more modern build available, many who played the game from the early days prefer to stick with what they know, and continue to run a version of the game that has now become known as Old School RuneScape.

[Austin Blake] is one of those early adopters, and the work he put into this LED health indicator should tell you all you need to know about how dedicated he is to the classic game. The 3D printed heart holds an incredible 312 NeoPixel LEDs, which are controlled by a 5 volt compatible Arduino Nano Every located on the back side.  Both the color and “fill level” of the heart will change in real-time to correspond to the health of the player character.

Building the light itself was pretty straightforward, but getting the health value from the game was another story. As [Austin] explains in the video, his first attempt involved using Python and some image recognition routines to literally read the indicator off of the screen. The idea worked, and is frankly a fascinating hack worth keeping in mind on its own, but unfortunately it was too slow to provide the real-time feedback he was looking for.

Eventually he turned his attention to RuneLite, which is an open source client for Old School RuneScape. Thanks to its open source nature he could have hacked a routine to read the current health value and send it off to the Arduino, but thanks to a mature plug-in system, he didn’t have to.

The game’s API let him create a simple and reliable way of getting the data out of the game, similar to what we see in the flight simulator community for driving physical gauges and displays. RuneLite features a repository of community-developed plugins, and [Austin] says that he’d be happy to submit his for inclusion if others are interested in building similar indicators — a perfect match for this motion-sensing RuneScape axe.

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Linux Fu: Easy Widgets

June 2, 2022 by 5 Comments

Here’s a scenario. You have a microcontroller that reads a number of items — temperatures, pressures, whatever — and you want to have a display for your Linux desktop that sits on the panel and shows you the status. If you click on it, you get expanded status and can even issue some commands. Most desktops support the notion of widgets, but developing them is a real pain, right? And even if you develop one for KDE, what about the people using Gnome?

Turns out there is an easy answer and it was apparently inspired by, of all things, a tool from the Mac world. That tool was called BitBar (now XBar). That program places a widget on your menu bar that can display anything you want. You can write any kind of program you like — shell script, C, whatever. The output printed from the program controls what appears on the widget using a simple markup-like language.

That’s fine for the Mac, but what about Linux? If you use Gnome, there is a very similar project called Argos. It is largely compatible with XBar, although there are a few things that it adds that are specific to it. If you use KDE (like I do) then you’ll want Kargos, which is more or less a port of Argos and adds a few things of its own.

Good News, Bad News

The good news is that, in theory, you could write a script that would run under all three systems. The bad news is that each has its own differences and quirks. Obviously, too, if you use a complied program that could pose a problem on the Mac unless you recompile.

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Surprisingly Stomp-able Soft Switches

June 2, 2022 by 13 Comments

Competition sure brings out the brute in people, doesn’t it? So what do you do when you need a bunch of switches you can let people fist-pound or stomp on repeatedly without them taking damage? You could look to the guitar pedal industry and their tough latching switches, or you could simply build your own smash-resistant buttons as [wannabemadsci] has done.

The main thing about these switches is that they aren’t easily destroyed by shoes or angry fists. That’s because the shiny red push-me part of the button is made by cutting a foam ball in half.

Not easily crush-able Styrofoam, mind you — squishy, coated foam like an indoor football. This is mounted to the top of a sandwich made of hardboard and a couple pieces of easily-compressible foam from craft paintbrushes.

A brass washer is mounted to the middle of both pieces of hardboard, and these have wires soldered to them to read button presses. Then it’s just a matter of hooking it to a microcontroller like any other momentary.

There are all kinds of things you could cut in half for the top, like maybe tennis balls. Or, do what [Sprite_TM] did and use inverted plastic bowls.

The Great Euro Sat Hack Should Be A Warning To Us All

June 2, 2022 by 46 Comments

Military officials and civilian security researchers have been warning us for years: cyberattacks are becoming a very real part of modern warfare. Far from being limited to military targets, cyberattacks can take out everything from vital public infrastructure to commercial and industrial operations, too.

In the early hours of February 24, as the Russian invasion force began raining missiles on Ukrainian cities, another attack was in progress in the digital realm. Suddenly, satellite terminals across Europe were going offline, with many suffering permanent damage from the attack.

Details remain hazy, but researchers and military analysts have pieced together a picture of what happened that night. The Great Euro Sat Hack prove to be the latest example of how vulnerable our digital infrastructure can be in wartime.

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Life-Sized Colonial Viper Touches Down In Australia

June 2, 2022 by 15 Comments

Don’t worry, this 8.4 meter (27 foot) Australian Viper won’t bite, but it’s likely to do a number on any Cylon Raiders that wander too close to Canberra. As recently reported by Riotact, creator [Baz Am] has been painstakingly piecing together this 1:1 scale replica of a Colonial Viper Mark II from the reimagined Battlestar Galactica series in his shed for several years now, and at this point things are really starting to come together.

On his personal site, [Baz] has been maintaining a build log for the fictional spacecraft since 2017 that covers everything from the electronics that power the cockpit displays to the surprisingly intricate woodworking that went into the lathe-turned 30 mm cannons. He’s even documented interviews he conducted with members of the show’s special effects team in his quest to get his version of the Viper to be as screen-accurate as possible.

Plywood bulkheads are mounted to an internal metal frame.

No matter how you look at this build, it’s impressive. But one thing we especially appreciated was the skill with which [Baz] manages to repurpose what would otherwise be junk. For example, the main cockpit display is actually an in-dash navigation system pulled from a car, and the engine’s turbine blades are cut out of aluminum road signs. He’s even managed to outfit the Viper with an array of real aircraft instruments by collecting broken or uncalibrated units from local pilots.

While the Viper might look like it’s ready to leap into action at a moment’s notice, there’s still quite a bit of work to be done. The craft’s fuselage, made of metal, wood, and foam, needs to be coated with fiberglass, sanded, and then painted to match its televised counterpart. [Baz] says that process will take at least another year, but also mentions off-hand that he’s thinking of adding a functional reaction-control system with cold gas thrusters — so we’re going to go out on a limb and say this is probably one of those projects that’s never quite finished. Not that we’re complaining, mind you. Especially when you consider the shaky track record the Battlestar Galactica franchise has when it comes to neatly wrapping things up in the finale. Continue reading “Life-Sized Colonial Viper Touches Down In Australia” →

Have You Heard Of MCGA?

June 2, 2022 by 21 Comments

In the world of PC graphics, the early standards followed the various video cards of the day. There was MDA, familiar through the original text-based DOS prompt, CGA, then EGA, and the non-IBM Hercules along the way. Finally in 1987 IBM produced the VGA, or Video Graphics Array standard for their PS/2 line of computers, which became the bedrock on which all subsequent PC graphics cards, even those with digital outputs, have been built. It’s interesting then to read an account from [Dave Farquhar] of the other now-forgotten video standard that made its debut with the PS/2, MCGA, or Multicolor Graphics Array. This was intended as an entry-level graphics system to compete with the more multimedia-oriented home computers of the day such as the Commodore Amiga and Atari ST.

Offering 320×200 graphics at 256 colors but only two colors at 640×480 it’s difficult to see how it could have been a viable competitor to the Amiga’s 4096-color HAM mode, but it did offer the ability to drive an RGB monitor through its VGA-like socket. The story goes that IBM intended it to provide an upgrade incentive for PS/2 customers to buy a more powerful model with VGA, but in the event a host of third-party VGA-compatible cards emerged and allowed more traditional ISA computers from third parties to retain a competitive edge and eventually sideline the PS/2 line entirely.

We called time on VGA back in 2016, and it’s fair to say that it’s disappeared from PC hardware since then even if much of its technologies still lurk within. It’s pleasing to see though that it remains a stalwart of hacked-together display interfaces, with efforts such as this 7400-based VGA card continuing to impress us.