Hackaday Links: March 17, 2019

There’s now an official Raspberry Pi keyboard and mouse. The mouse is a mouse clad in pink and white plastic, but the Pi keyboard has some stuff going for it. It’s small, which is what you want for a Pi keyboard, and it has a built-in USB hub. Even Apple got that idea right with the first iMac keyboard. The keyboard and mouse combo are available for £22.00

A new Raspberry Pi keyboard and a commemorative 50p coin from the Royal Mint featuring the works of Stephen Hawking? Wow, Britain is tearing up the headlines recently.

Just because, here’s a Power Wheels Barbie Jeep with a 55 HP motor. Interesting things to note here is how simple this build actually is. If you look at some of the Power Wheels Racing cars, they have actual diffs on the rear axle. This build gets a ton of points for the suspension, though. Somewhere out there on the Internet, there is the concept of the perfect Power Wheels conversion. There might be a drive shaft instead of a drive chain, there might be an electrical system, and someone might have figured out how someone over the age of 12 can fit comfortably in a Power Wheels Jeep. No one has done it yet.

AI is taking away our free speech! Free speech, as you’re all aware, applies to all speech in all forms, in all venues. Except you specifically can’t yell fire in a movie theater, that’s the one exception. Now AI researchers are treading on your right to free speech, an affront to the Gadsden flag flying over our compound and the ‘no step on snek’ patch on our tactical balaclava, with a Chrome plugin. This plugin filter’s ‘toxic’ comments with AI, but there’s an unintended consequence: people want need to read what I have to say, and this will filter it out! The good news is that it doesn’t work on Hackaday because our commenting system is terrible.

This week was the 30th anniversary of the World Wide Web, first proposed on March 11, 1989 by Tim Berners-Lee. The web, and to a greater extent, the Internet, is the single most impactful invention of the last five hundred years; your overly simplistic view of world history can trace modern western hegemony and the reconnaissance to Gutenberg’s invention of the printing press, and so it will be true with the Internet. Tim’s NeXT cube, in a case behind glass at CERN, will be viewed with the same reverence as Gutenberg’s first printing press (if it had survived, but you get where I’m going with this). Five hundred years from now, the major historical artifact from the 20th century will be a NeXT cube, that was, coincidentally, made by Steve Jobs. If you want to get your hands on a NEXT cube, be prepared to pony up, but Adafruit has a great authorial for running Openstep on a virtual machine. If you want the real experience, you can pick up a NeXT keyboard and mouse relatively cheaply.

Sometimes you need an RCL box, so here’s one on Kickstarter. Yeah, it’s kind of expensive. Have you ever bought every value of inductor?

Posted in ai, Hackaday Columns, Hackaday links, NeXT, Power Wheels, Raspberry Pi, RCL | Leave a comment

Vintage Atari Becomes Modern Keyboard

The modern keyboard enthusiast is blessed with innumerable choices when it comes to typing hardware. There are keyboards designed specifically for gaming, fast typing, ergonomics, and all manner of other criteria. [iot4c] undertook their own build for no other reason than nostalgia – which sounds plenty fun to us.

An Arduino Leonardo is pressed into service for this hack. With its USB HID capabilities, it’s perfectly suited for custom keyboard builds. It’s built into a working Atari 65XE computer, and connected to the keyboard matrix. The Keypad and Keyboard libraries are pressed into service to turn keypresses on the 80s keyboard into easily digseted USB data.

There’s plenty of room inside the computer for the added hardware, with the USB cable neatly sneaked out the rear. [iot4c] notes that everything still works and the added hardware does not cause any problems, as long as it’s not used as a computer and a keyboard at the same time.

It’s possible to do a similar hack on the Commodore 64, too. If you’re doing tricky keyboard builds yourself, you know where to send ’em.

Posted in arduino, Arduino Hacks, Arduino Leonardo, atari, keyboard, retrocomputing, usb hid | Leave a comment

Custom Calculator Rolls D20 So You Don’t Have To

There are a number of sticking points that can keep new players away from complex tabletop games such as Dungeons & Dragons. Some people are intimidated by the math involved, and of course others just can’t find enough friends who are willing to sit down and play D&D with them in 2019. While this gadget created by [Caleb Everett] won’t help you get more open minded friends, it will take some of the mental gymnastics out of adding up dice rolls.

In its current form the device saves you from the hassle of not only having to roll various combinations of physical dice, but adding up all the faces after the fact as well. In the future [Caleb] plans on adding more advanced software features which will allow for tricks not possible with real dice, such as increasing the likelihood of rolling numbers which haven’t been seen in awhile. Now that the hardware is put together, he’s free to dig into the software side of things and really get creative.

Inside the 3D printed case of his calculator there’s a Adafruit Feather M0 Express, a 128 x 32 OLED display, and a 2200 mAh lithium ion battery that lets him go mobile. The keys, which are Cherry MX clones, are wired directly to the digital pins of the Feather board as [Caleb] found that easier to wrap his head around than doing a matrix. This ended up working out as he had enough pins, but does stifle future expansion a bit.

Even if you aren’t into the sort of tabletop gaming which would benefit from an automatic dice roller and tabulator, we think [Caleb] has come up with a very neat form factor for similar pocket sized gadgets. It reminds us of the Handlink from Quantum Leap; before the prop department swapped it out for a jumble of gummy bears later on in the series, anyway. Since he’s shared the link to the OnShape project, you can even tweak the design a bit without having to suffer through modifying the STLs.

Many of the electronic dice we’ve seen in the past have tried to emulate the size and appearance of traditional dice, so it’s interesting to see this approach which goes in the opposite direction entirely. Critics might say that at some point you’d be better off just using a software application for your smartphone, but we’re not in the business of complaining when people produce interesting pieces of hardware.

Posted in calculator, cherry mx, Feather M0, Games, Microcontrollers, oled, OnShape | Leave a comment

Making A 1940s Radio Digital With Nixies

Classix Philly One Oh Seven Nine is your home for Philly soul right at the top of the dial, and now you know why this writer isn’t allowed on the Hackaday podcast. That phrase, ‘top of the dial’ doesn’t mean much these days because we all have radios with a digital display and seek buttons. There was a time when radios actually had dials, but [glasslinger] is in a class all by himself. He’s adding a digital display to a 1940s radio, and he’s doing it with Nixie tubes.

The circuitry for the digital display for this AM radio requires getting the frequency the radio is tuned to. This is done by counting the oscillator frequency, then subtracting the IF. [glasslinger] is doing this with an Arduino (hey, it’s a legitimate engineering choice) and a 4040 12-bit binary counter as a pre-scaler. The Arduino does the math and then drives a few 74141 Nixie drivers, which then display the frequency of the receiver in beautiful glass tubes. Add in a single neon bulb for the thousands digit, and you have a four-digit display that will tell you the frequency you’re tuned to on an old AM radio.

The rest of the build consists of fixing up an old radio and gluing the veneer down again with modern glues that will last another seventy years. The finished cabinet was sanded, a bezel for the display was added, and since [glasslinger] has the equipment, he made a new, long neon tube to light up with the volume of the radio. And you thought a cat’s eye detector was cool.

This build is a tour de force, and something that is so incredibly modern but at the same time built on vintage technology. If you’ve got an hour and a half, we highly recommend checking out the build video below.

Posted in Glasslinger, nixie, radio, radio hacks | Leave a comment

Building A Magnetic Loop Antenna

Antennas come in many shapes and sizes, with a variety of characteristics making them more or less suitable for various applications. The average hacker with only a middling exposure to RF may be familiar with trace antennas, yagis and dipoles, but there’s a whole load more out there. [Eric Sorensen] is going down the path less travelled, undertaking the build of a self-tuning magnetic loop antenna. 

[Eric]’s build is designed to operate at 100W on the 20 meter band, and this influences the specifications of the antenna. Particularly critical in the magnetic loop design is the voltage across the tuning capacitor; in this design, it comes out at approximately 4 kilovolts. This necessitates the careful choice of parts that can handle these voltages. In this case, a vacuum variable capacitor is used, rated to a peak current of 57 amps and a peak voltage of 5 kilovolts.

The magnetic loop design leads to antenna which is tuned to a very narrow frequency range, giving good selectivity. However, it also requires retuning quite often in order to stay on-band. [Eric] is implementing a self-tuning system to solve this, with a controller using a motor to actuate the tuning capacitor to maintain the antenna at its proper operating point.

If you’re unfamiliar with magnetic loop builds, [Eric]’s project serves as a great introduction to both the electrical and mechanical considerations inherent in such a design. We’ve seen even more obscure designs though – like these antennas applied with advanced spray techniques.

Posted in antenna, antenna build, ham radio, magnetic loop antenna, radio, radio hacks | Leave a comment

The Enlightenment Turns Light And Noise Into Sound

We’re all familiar with the subtle sounds of electrical equipment present in daily life. There’s the high-pitched whine of a CRT, the mains hum of a poorly isolated audio amplifier, and the wailing screams of inductors. Typically these sounds go unnoticed unless something is malfunctioning or otherwise wrong. However, Quiet Ensemble decided to capture these noises and turned them into a performance they call The Enlightenment.

The basic setup consists of a series of lights, most of which are theatrical in nature. There are spotlights, a series of neons, and even a few bright strobes. Copper coils are used to pick up the stray electrical noises generated by these lights in operation. These noises are then fed to mixers, amplifiers, and other audio equipment to allow the performers to control the audio as they wish.

The end result is a mechanical, and at times, brutal soundscape that wouldn’t sound out of place on the Homeworld soundtrack. Flashing strobes contribute rhythm while the rest of the lights lend their droning and whining to fill out the ensemble.

If it’s a little too niche for your tastes, the Triforium may be more to your liking. Video after the break.

Posted in art, emf, sound and light | Leave a comment

Printable Filament Spool Hub Skips the Bearings

When you really start fine-tuning your 3D printer, you might start to notice that even the smallest things can have a noticeable impact on your prints. An open window can cause enough of a draft to make your print peel up from the bed, and the slightly askew diameter of that bargain basement filament can mess up your extrusion rate. It can be a deep rabbit hole to fall down if you’re not careful.

One element that’s often overlooked is the filament spool; if it’s not rotating smoothly, the drag it puts on both the extruder and movement of the print head can cause difficult to diagnose issues. For his custom built printer, [Marius Taciuc] developed a very clever printable gadget that helps the filament roll spin using nothing but the properties of the PLA itself. While the design might need a bit of tweaking to work on your own printer, the files he’s shared should get you most of the way there.

All you need to do is print out the hubs which fit your particular filament spools (naturally, they aren’t all a standard size), and snap them on. The four “claws” of the hub lightly contact a piece of 8 mm rod enough to support the spool while limiting the surface area as much as possible. The natural elasticity of PLA helps dampen the moment that would result if you just hung the hub-less spool on the rod.

The STL files [Marius] has provided for his low-friction hubs should work fine for anyone who’s interested in trying out his design, but you’ll need to come up with your own method of mounting the 8 mm rod in a convenient place. The arms he’s included are specifically designed for his customized Prusa Mendel, which is pretty far removed from contemporary desktop 3D printer design. Something to consider might be a piece of 8 mm rod suspended over the printer, with enough space that you could put a couple spools on for quick access to different colors or materials.

Hackers have been trying to solve the spool friction issue for years, and as you might expect we’ve seen some very clever designs in the past. But we especially like how simple [Marius] has made this design, and the fact that you don’t need to source bearings to build it. If you’re thinking of giving this new design a shot, be sure to leave a comment so we know how it worked out for you.

Posted in 3d Printer hacks, bearing, filament spool, hub, PLA, smooth rod | Leave a comment

Tweetbot Expresses Twitter Emotions

When reading textual communications, it can be difficult to accurately acertain emotional intent. Individual humans can be better or worse at this, with sometimes hilarious results when it goes wrong. Regardless, there’s nothing a human can do that a machine won’t eventually do better. For just this purpose, Tweetbot is here to emotionally react to Twitter so you don’t have to.

The ‘bot receives tweets over a bluetooth link, handled by a PIC32, which also displays them on a small TFT screen. The PIC then analyses the tweet for emotional content before sending the result to a second PIC32, which displays emotes on a second TFT screen, creating the robot’s face. Varying LEDs are also flashed depending on the emotion detected – green for positive emotions, yellow for sadness, and red for anger.

The final bot is capable of demonstrating 8 unique emotional states, far exceeding the typical Facebook commenter who can only express unbridled outrage. With the ‘bot packing displays, multiple microcontrollers, and even motor drives, we imagine the team learned a great deal in the development of the project.

The project was the product of [Bruce Land]’s ECE 4760 course, which has shown us plenty of great hacks in the past – Bike Sonar being one of our favorites. Video after the break.

Posted in bruce land, ece 4760, ece4760, pic32, robot, robots hacks, twitter | Leave a comment

A Soap Film Photography How-To

Blowing bubbles is a pastime enjoyed by young and old alike. The pleasant motion and swirling colors of the bubbles can be remarkably relaxing. With the right tools and techniques, it’s possible to take striking photos of these soap film phenomena, and that’s exactly what [Eric] and [Travis] did.

Adding sugar to the soap solution increases the resilience of the film significantly. With enough added, the film no longer pops, but instead breaks and fails in interesting ways.

After beginning with a robotic arm and a computer fan blowing bubbles, the project moved towards a simple stepper motor setup. A thin frame is lowered into a solution of soapy water, then brought back up by the stepper motor. The resulting soap film is held in front of a black background and carefully lit with a softbox light.

Lens selection is critical for this sort of work – in this case, a TS-E 50mm Macro f/2.8 lens was the order of the day. [Eric] shares other tips for taking great shots, such as adding sugar to the solution to make the soap film last longer, and using a modified speaker to help “paint” the surface of the films.

The resulting images are beautiful examples of the art, showing vibrant colors from the interference patterns created by the light. [Eric] has done a great job of clearly documenting the development process and the final results, making it possible for others to recreate the project elsewhere.

We’ve seen other soapy projects before, like this automatic bubble blowing machine. Video after the break.

Posted in digital cameras hacks, macro, macro lens, macro photography, photo, photography, soap, soap film | Leave a comment

An Airbag Charge To Launch A Projectile

It’s not particularly easy to buy small explosive charges. At least, it’s not in the UK, from where [Turbo Conquering Mega Eagle] hails. But it is surprisingly easy to get your hands on one because most people drive around with one right in front of them in the form of their car airbag. In a burst of either genius or madness, we can’t decide which, he decided to use an airbag charge to launch a projectile.

As you can see in the video below, he launches straight into dismantling the centre of a Renault steering wheel before seemingly abandoning caution and taking a grinder to the charge inside. It’s a fascinating deconstruction though, because it reveals not one but two differently sized charges separated by a space which appears to contain some kind of wadding.

His projectile is a piece of steel tube with a turned steel point, spigot launched over a tube placed in front of a breech in which he places the charge. The launch tube has a piece of metal welded within it, he tells us to render it legal by being unable to launch a projectile from within it. Upon firing at a scrap jerry can it has enough energy to easily pass through both its steel walls, so it’s quite a formidable weapon.

He assures the viewer that with the spigot-launched design he’s not breaking the law, but we’re not sure we’d like to have to explain that one to a British policeman. He does make the point though that while it’s an impressive spectacle it’s also quite a dangerous device, so maybe don’t do this at home.

If ripping airbags to pieces isn’t your thing, how about making one from scratch?

Posted in airbag, arrow launcher, spigot launched, weapons hacks | Leave a comment