Virtual Pinball Cabinet Provides Real Thrills

Being a fan of pinball is bittersweet these days. In the go-go 1990s, you could still find pins in places like coffeehouses and the odd gas station here and there as the commercial arcade began to fade into the past. Things were looking up once booze-fueled b-arcades became a thing, but the pandemic economy may come for them soon enough.

Poor [smithsa3] doesn’t have a table around for hundreds of miles. Instead of settling for an older table or agonizing over the average price of newer tables, [smithsa3] found a happy medium and built a full-size virtual pinball cabinet to play pretty much any table there is. The only non-negotiable game was Addams Family, which you can see in the demo after the break.

Inside is a PC running PinballX, along with a 37″ TV for the playfield and two 17″ monitors that make up the backboard. Between the physical inputs and the faithful recreations of current and classic pinball games that are out there, this really is the best of both worlds.

We love that [smithsa3] combined stock and DIY hardware to pull this together. The cabinet uses standard legs and arcade buttons, but [smithsa3] built the plunger, interfaced it with an old keyboard controller, and made a coin slot mechanism that rejects everything but 10p coins.

Spend enough time playing pinball, and you’ll no doubt begin to fantasize about building your own. We’ve seen one or two of those, but not too many that can play themselves.

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Plot And Visualise Brain Data In An Artwork

One of the most interesting streams through which we receive new projects to write about here at Hackaday comes from the intersection between technologists and artists. Those artists who straddle both disciplines bring creativity that those of us without their backgrounds can only dream of. The artist [Rosa Francesca] produced a piece called Cinematica, in which she monitored her brain waves with an EEG and from them produced on-paper visualizations with a pen plotter.

The hardware in use is an Interaxon Muse EEG headband read through the Muse Monitor app, and some code to drive an Evil Mad Scientist AxiDraw V3 plotter via its serial port. The write-up goes in some depth into the different types of brain waves, explaining her choice of monitoring gamma and theta waves for her source data. The result is a series of repeating shapes that vary with the brain waves of the wearer, creating drawings that are both pleasing and unique.

If you’re interested by the Muse headset used in this artwork, you might find a teardown we covered a few years ago to be of interest. And if you’re tempted by the plotter, you can always try making your own.

Thanks, @tanurai for the tip!

Making Custom Gradient Markers At Home

When doing high-end industrial illustration work, smooth gradients add a lot of production value to the final product. However, markers designed to do this well can be difficult to lay your hands on. [Eric] decided to create his own set of custom gradient markers, using commonly available supplies.

Starting with some existing markers that have dried out, the fabric ink reservoir inside is removed. A new one is created using tampons wrapped in heat-shrink, to replicate the construction of the original. Alcohol-based ink is required for smooth gradients, and [Eric] suggests using a heat gun to harvest the ink from a ballpoint pen, if store-bought is not available. The ink is then mixed with denatured alcohol to dilute it and injected into the fabric reservoir using a syringe. Each marker gets a slightly different ink mix to hit a range of lightness values for making smooth gradients.

It’s a tidy way of creating your own gradient markers in whatever color you may find useful. As a plus, the materials to do so are cheap and easy to obtain. We could even imagine 3D-printed marker bodies being an option, though nibs might prove a touch more difficult. We’ve seen [Eric]’s work before too, like this well-illustrated guide to using cardboard in product design. Video after the break.

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Hackaday Links: June 14, 2020

You say you want to go to Mars, but the vanishingly thin atmosphere, the toxic and corrosive soil, the bitter cold, the deadly radiation that sleets down constantly, and the long, perilous journey that you probably won’t return from has turned you off a little. Fear not, because there’s still a way for you to get at least part of you to Mars: your intelligence. Curiosity, the Mars rover that’s on the eighth year of its 90-day mission, is completely remote-controlled, and NASA would like to add some self-driving capabilities to it. Which is why they’re asking for human help in classifying thousands of images of the Martian surface. By annotating images and pointing out what looks like soil and what looks like rock, you’ll be training an algorithm that one day might be sent up to the rover. If you’ve got the time, give it a shot — it seems a better use of time than training our eventual AI overlords.

We got a tip this week that ASTM, the international standards organization, has made its collection of standards for testing PPE available to the public. With titles like “Standard Test Method for Resistance of Medical Face Masks to Penetration by Synthetic Blood (Horizontal Projection of Fixed Volume at a Known Velocity)”, it seems like the standards body wants to make sure that that homebrew PPE gets tested properly before being put into service. The timing of this release is fortuitous since this week’s Hack Chat features Hiram Gay and Lex Kravitz, colleagues from the Washington University School of Medicine who will talk about what they did to test a respirator made from a full-face snorkel mask.

There’s little doubt that Lego played a huge part in the development of many engineers, and many of us never really put them away for good. We still pull them out occasionally, for fun or even for work, especially the Technic parts, which make a great prototyping system. But what if you need a Technic piece that you don’t have, or one that never existed in the first place? Easy — design and print your own custom Technic pieces. Lego Part Designer is a web app that breaks Technic parts down into five possible blocks, and lets you combine them as you see fit. We doubt that most FDM printers can deal with the fine tolerances needed for that satisfying Lego fit, but good enough might be all you need to get a design working.

Chances are pretty good that you’ve participated in more than a few video conferencing sessions lately, and if you’re anything like us you’ve found the experience somewhat lacking. The standard UI, with everyone in the conference organized in orderly rows and columns, reminds us of either a police line-up or the opening of The Brady Bunch, neither of which is particularly appealing. The paradigm could use a little rethinking, which is what Laptops in Space aims to do. By putting each participant’s video feed in a virtual laptop and letting them float in space, you’re supposed to have a more organic meeting experience. There’s a tweet with a short clip, or you can try it yourself. We’re not sure how we feel about it yet, but we’re glad someone is at least trying something new in this space.

And finally, if you’re in need of a primer on charlieplexing, or perhaps just need to brush up on the topic, [pileofstuff] has just released a video that might be just what you need. He explains the tri-state logic LED multiplexing method in detail, and even goes into some alternate uses, like using optocouplers to drive higher loads. We like his style — informal, but with a good level of detail that serves as a jumping-off point for further exploration.

Notification Wearable Helps Get Child’s Attention

Getting a child’s attention can be difficult at the best of times. Add deafness into the picture, and it’s harder again. [Jake]’s daughter recently had to go without her cochlear implants, raising this issue. Naturally, he whipped up some hardware to solve the problem.

[Jake]’s solution was to devise a vibrating wristband that could be used to get his daughter’s attention. An Adafruit Trinket M0 is used to vibrate a pager motor, using a DRV2605 motor driver. This is paired with a Tile Bluetooth device, allowing the unit to interface with Google Assistant. This allows [Jake] to get his daughter’s attention with a simple voice command to a smartphone, tablet or smart speaker.

While [Jake]’s daughter will regain her cochlear implants soon, they do have limitations as far as hearing distant sounds and working in high-noise environments. It’s likely that this little gadget will prove useful well into the future, and could serve others well, too. Wearable notification devices are growing more popular; this OLED ring is a particularly good example. Video after the break.

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OmniBallot, Another Flawed Attempt At Online Voting

Although online voting in elections has been a contentious topic for decades already, it is during the current pandemic that it has seen significant more attention. Along with mail-based voting, it can be a crucial tool in keeping the world’s democratic nations running smoothly. This is where the OmniBallot software, produced by Democracy Live, comes into play, and its unfortunate unsuitability for this goal.

Despite already being used by multiple US jurisdictions for online voting, a study by MIT’s [Michael Specter] and University of Michigan researchers points out the flaws in this web-based platform. Their recommendations are to either avoid using OmniBallot completely, or to only use it for printing out a blank ballot that one then marks by hands and sends in by mail.

One of the issues with the software is that it by default creates the marked ballot PDF on the Democracy Live servers, instead of just on the user’s device. Another is that as a web-based platform it is hosted on Amazon Web Services (AWS), with JavaScript sources pulled from both CloudFlare and Google servers. Considering that the concern with electronic voting machines was that of unauthorized access at a polling station, it shouldn’t require a lengthy explanation to see this lack of end-to-end security with OmniBallot offers many potential attack surfaces.

When Ars Technica contacted Democracy Live for commentary on these findings, Democracy Live CEO [Bryan Finney] responded that “The report did not find any technical vulnerabilities in OmniBallot”. Since the researchers did not examine the OmniBallot code itself that is technically true, but misses the larger point of the lack of guarantee of every single voter’s device being secured, as well as every AWS, CloudFlare and Google instance involved in the voting process.

As a result, the recommended use of OmniBallot is to use it for the aforementioned printing out of blank ballots, to save half of the trip time of the usual mail-in voting.

Dial In Your Multi-Headed 3D Printer With 2020 Machine Vision

Most folks that have been poking around at multi-tool 3D printing know that lining up nozzles can be a gnarly, but necessary pain point. Existing methods either have us measure offsets with a vernier scale or with a series of pictures taken with an upwards-facing camera. And this step is not to be ignored! Any mismatch between nozzles, and your multicolor prints end up looking like Scotty really screwed up those sliders on that transporter beam console. Fear not, however! [Danal] took this problem as an opportunity to write something that’s completely automated and brought to you by some machine vision.

Dubbed TAMV, for Tool Align Machine Vision, [Danal] added a Raspberry Pi alongside his existing 3D printing motion controller in addition to an upwards facing camera. A few lines of code (and a few hours of compiling OpenCV) later, and he had himself a circle-detecting script that automatically cycles through each tool, detects the nozzle center, and calculates an offset for each tool that’s stored into the machine’s configuration file. If that’s not nifty enough, he’s made the entire setup open-source, and he included both an installation script for compiling OpenCV and a well-written set of step-by-step instructions.

In a world where most hobbyists approaches still solve this problem manually, this is leaps and bounds ahead of what we know, and it’s a great application of machine vision built on top of a stack of recognizable hardware and software. While this project was outfitted for a Jubilee running a Duet3 controller with a Raspberry Pi connected in “single-board computer” mode, the core features are readily adaptable to any other multi-tool machine with a similar control board stack. And for folks willing to poke under the hood, the project could even be extended to a standalone script that you can run on your PC locally to simply print the tool offsets separately.

Alongside TAMV, it’s refreshing that even a decade after 3D printers have been with us, we’re still finding ways to make these machines more capable. For more fresh hacks in this category, check out a new spin on using sharpie ink as a support material release agent.

Sadly, [Danal] has recently passed away in the last week, but we are grateful to capture a snapshot in the history of this person’s life.

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