Hackaday Prize 2023: An Anti-Tremor Handle, With No Electronics

Many of us will have seen the various active assistive devices which have appeared over the last few years to help people with a hand tremor. Probably the best known was a fork with a set of servos and an accelerometer, that kept the end of the utensil steady despite the owner’s hand movements. It’s a field which has the potential to help many people, but it’s undeniable that such technology comes with a cost.

What if the same effect could be achieved passively, without all those electronics? It’s something [Jacob] is investigating with his mechanical anti-tremor cup handle. It’s a university project completed as part of his studies so it’s very much a work-in-progress which if we’re being fair isn’t quite there yet, but we think the potential in this idea of bringing a useful assistive device at least bears further attention.

The write-up is available as a Norwegian PDF file so takes a little bit of Google Translate cut and pasting for an Anglophone. Sadly due to what must be report format requirements set by the university it’s long on procedure and shorter on engineering calculations than we’d like, but there’s an attempt to calculate the properties of the helical springs in each of the joints to match the likely forces. Our intuition is that the design as shown would require significantly more mass on the end of it than that of the mug and beverage alone to achieve some form of stability, but despite that as we said it’s an interesting enough idea that it deserves more thought.

Hand tremor assistive devices have appeared more than once on these pages before, here’s one for soldering that enlists the aid of a camera gimbal.

A handheld computer made on a piece of prototyping board running a Tetris clone

Tetris Clone Uses 1000 Lines Of Code, And Nothing Else

If you’re programming on a modern computer, you typically make use of lots of work done by other people. There’s operating systems to abstract away the complexities of modern hardware, standard libraries to implement common tasks, and tons of third-party libraries that prevent you from having to reinvent the wheel all the time: you’re definitely not the first one trying to draw graphics onto a screen or store data in a file.

But if it’s the wheels you’re most interested in, then there’s nothing wrong with inventing new ones now and then. [Michal Zalewski], for instance, has made a beautiful Tetris clone in just 1000 lines of C, without using anyone else’s code.

The purpose of this exercise is to show that it’s possible to make a game with graphics comparable to modern, complex computing systems, without relying on operating systems or third-party libraries. The hardware consists of not much more than an ARM Cortex-M7 MCU, a 240×320 LCD screen and a few buttons soldered onto a piece of prototyping board, all powered by a set of AAA batteries.

The software is similarly spartan: just pure C code running directly on the CPU core. Graphic elements, some generated by AI and others hand-drawn, are stored in memory as plain bitmaps. They are manipulated by 150 lines of code that shuffles sprites around the display at a speed high enough to generate smooth motion. Game mechanics take up about 250 lines, while sound consists of simple square-wave chiptunes written in just 50 lines of code.

[Michal]’s code is very well documented, and his blog post gives even more details about all the problems he had to solve. One example is the length of keypresses: when do you interpret a keypress as a single “press”, and when does it become “press and hold”? Apparently, waiting 250 ms after the first press and 100 ms after subsequent ones does the trick. [Michal] is a bit of an expert on bare-bones game programming by now: he has previously pushed several 8-bit micros to their very limits. Third-party libraries can make your programming life a lot easier, but it’s good to reflect on the dangers of relying too much on other people’s code.

Continue reading Tetris Clone Uses 1000 Lines Of Code, And Nothing Else”

Squid-Con Brings Joy To All

While we’re always happy to see accessibility aids come into fruition, most of them focus on daily tasks, not that there’s anything wrong with that. But what about having some fun? That’s the idea behind [Akaki Kuumeri]’s accessibly-awesome Joy-Con controller, the Squid-Con, which provides access to every button with just one hand. It even has tripod and AMPS mounts.

The joysticks themselves are controlled with the thumb and pinky, although some of [Akaki]’s beta testers changed it up a bit. That’s okay, because it’s designed to be comfortable in a variety of positions for either hand. As for the ABXY buttons, those are actuated using 3D-printed arms that connect to a central piece which [Akaki] calls the turbine.

But perhaps the coolest part of this project is the flexures that actuate the shoulder buttons (L, R, zL, and zR) on the controllers. It’s a series of four arms that are actuated by bringing the fingers back toward the palm. If all of this sounds confusing, just check out the video after the break.

We love flexures around here, and we’ve seen them in everything from cat feeding calendars to 6-DOF positioners to completely new kinds of joysticks.

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A Guide To Field Stripping Your Voyager Tricorder

For the last few years, [Mangy_Dog] has been working on what is easily the most technically and aesthetically impressive Star Trek tricorder prop the world has ever seen. With each new version of the hardware we’ve gotten the occasional peek under the hood or source code walk-through, but these limited presentations have made it somewhat difficult to really appreciate the scale of this undertaking.

But now thanks to this epic hour-long tour of the hardware and software that makes up version 2.5 of his Voyager tricorder, we can finally see just how incredible the engineering that’s gone into this project really is. Every detail has been meticulously considered to deliver a final product that’s not only as visually accurate as possible, but reliable enough to actually carry around. Continue reading “A Guide To Field Stripping Your Voyager Tricorder”

Opening A Curta — With Great Care

We’ve always admired Curta mechanical calculators, and would be very hesitant to dismantle one. But [Janus Cycle] did just that — and succeeded. A friend sent him a Curta Model 2 calculator that was frozen up. Just opening the case involved percussive force to remove a retaining pin, and once inside he discovered the main shaft had been slightly bent. No doubt this calculator had suffered a drop at some point in the past.

I’m sticking to the rule of doing no harm — I’d rather not be able to fix this than do something that causes more problems.

Inside the Curta

But surprisingly, he was able to get it substantially back in working order without completely taking apart all 600+ parts. Most of the issues were shafts whose lubrication had become gummy, and one carry lever was slightly bent. There is still a little more work, but soon this calculator will once again be cranking out results.

Has anyone dismantled a mechanical contraption this complicated before, for example a teletype machine? Let us know in the comments. If you want to brush up on your Curta knowledge, check out the Curta Calculator Page. We also wrote a Retrotechtacular about the Curta before. Thanks to [mister35mm] for sending in this tip.

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Blackberry Pi Puts Desktop Linux In Your Pocket

Let’s face it — Android wasn’t what most of us had in mind when we imagined having Linux running on our phones. While there’s a (relatively) familiar kernel hiding at the core of Google’s mobile operating system, the rest of the environment is alien enough that you can’t run Linux software on it without jumping through some hoops. While that’s fine for most folks, there remains a sizable group of users who still dream of a mobile device that can run a full Linux operating system without any compromises.

Judging by the work put into the Blackberry Pi, we’re willing to bet that [IMBalENce] falls into that camp. The custom handheld combines the Raspberry Pi Zero, a 320×240 LCD, and the BBQ20KBD keyboard from Solder Party with a 2500 mAh LiPo pouch cell and associated charging circuitry. Optionally, it also supports modules such as the Raspberry Pi Camera, a Real-Time-Clock, a ADS1015 ADC to read the battery voltage, and even a USB hub — although you can’t have all the goodies installed at once as it draws too much current.

Everything is packed into a 3D printed case that looks roughly like an original DMG-01 Game Boy if somebody replaced the bottom half with a tiny keyboard. We appreciate the ZX Spectrum theme, even if it’s not immediately clear how it relates to the project other than being an excuse to play around with multi-color printing. [IMBalENce] says the final product works quite well, though the relatively limited keys on the BlackBerry keyboard does make it tricky to use the device for writing code.

Interested in mobile Linux, but not trying to build the hardware yourself? We recently took a look at the SQFMI Beepy, which is fairly similar in terms of hardware, but very much in need of some talented penguin wranglers who are willing to come in and work on the software and documentation. Think you’re up for the challenge?

Review: Beepy, A Palm-sized Linux Hacking Playground

In the long ago times, when phones still flipped and modems sang proudly the songs of their people, I sent away for a set of Slackware CDs and embarked on a most remarkable journey. Back then, running Linux (especially on the desktop) was not a task to be taken lightly. The kernel itself was still in considerable flux — instead of changing some obscure subsystem or adding support for a niche gadget you don’t even own, new releases were unlocking critical capabilities and whole categories of peripherals. I still remember deciding if I wanted to play it safe and stick with my current kernel, or take a chance on compiling the latest version to check out this new “USB Mass Storage” thing everyone on the forums was talking about…

But modern desktop Linux has reached an incredible level of majority, and is now a viable choice for a great number of computer users. In fact, if you add Android and Chrome OS into the mix, there are millions and millions of people who are using Linux on daily basis and don’t even realize it. These days, the only way to experience that sense of adventure and wonderment that once came pre-loaded with a Linux box is to go out and seek it.

Which is precisely how it feels using using the Beepy from SQFMI. The handheld device, which was formerly known as the Beepberry before its creators received an all-too-predicable formal complaint, is unabashedly designed for Linux nerds. Over the last couple of weeks playing with this first-run hardware, I’ve been compiling kernel drivers, writing custom scripts, and trying (though not always successfully) to get new software installed on it. If you’re into hacking around on Linux, it’s an absolute blast.

There’s a good chance that you already know if the Beepy is for you or not, but if you’re still on the fence, hopefully this in-depth look at the hardware and current state of the overall project can help you decide before SQFMI officially starts taking new orders for the $79 gadget.

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