3D Print Your Very Own Mechanical Computer

November 10, 2019 by Bryan Cockfield 30 Comments

Most Hackaday readers are familiar with computers from the 70s and 80s, but what about ones even older than that? The Digi Comp 1 was a commercially available computer from the 1960s that actually cost less than a modern-day microcontroller. The catch? It was mechanical rather than electrical. Thanks to retro-wizard [Mike Gardi], now anyone can build a replica of one.

Admittedly the Digi Comp 1 was more of a toy than a tool, but it was still a working computer. It contained three flip-flops (memory) and had a lever that acted as a clock, allowing the user to perform boolean operations and some addition and subtraction. Certainly not advanced, but interesting nonetheless. [Mike]’s version of the Digi Comp 1 has an extra bit when compared to the original and includes some other upgrades, but largely remains faithful to the original design.

If you want to print one of these on your own, [Mike] has made all of the files available on Thingiverse. He has also experimented with other mechanical computers as well, including the sequel Digi Comp 2. We’ve seen some recent interest in that mechanical computer lately as well.

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This Radio Control Sailboat Uses 2X4s

November 8, 2019 by Al Williams 5 Comments

When [PeterSripol] was a kid, he made a simple sailboat from a scrap piece of 2×4 and some napkin sails. He’s not 8 years old anymore, but he decided he wanted to make another 2X4 sailboat using the skills he’s learned since he was a kid.

You’ll have to get past storytime and mice, but the build skill is evident. There’s a RC rudder, a keel with lead shot and overall it is a good looking boat for such a simple build.

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Why Buy Toys When You Can Build Them Instead?

November 8, 2019 by Tom Nardi 10 Comments

Like many creative individuals who suddenly find themselves parents, [Marta] wanted to make something special for his children to play with. Anybody can just purchase an off-the-shelf electronic toy, but if you’ve got the ability to design one on your own terms, why not do it? But even compared to the fairly high standards set by hacker parents, we have to admit that the amount of time, thought, and effort that was put into the “Marta Musik Maschine” is absolutely phenomenal.

[Marta] was inspired by the various commercial offerings which use RFID and other technologies to identify which characters the child is playing with and respond accordingly. But since he didn’t want to get locked into one particular company’s ecosystem and tinkering with the toys seemed frowned upon by their creators, he decided to just come up with his own version.

Over the course of many posts on the Musik Maschine’s dedicated website, [Marta] explains his thought process for every design consideration of the toy in absolutely exquisite detail. Each of the writeups, which have helpfully been broken down for each sub-system of the final toy, are arguably detailed and complete enough to stand as their own individual projects. Even if you’re not looking to get into the world of DIY electronic toys, there’s almost certainly an individual post here which you’ll find fascinating. From the finer points of interfacing your Python code with arcade buttons to tips for designing 3D printed enclosures, there’s really something for everyone here.

The children of hackers are often the envy of the neighborhood thanks to the one-of-a-kind playthings provided by their parents, and considering the level of commitment [Marta] has put into a toddler toy, we can’t wait to see what he comes up with next.

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LEGO And Minecraft Team Up For Custom Gaming PC Case

October 26, 2019 by Dan Maloney 4 Comments

There are probably few parents who haven’t watched their kids sitting on the floor, afloat on a sea of LEGO pieces and busily creating, and thought, “If only they could make a living at that.” But time goes on and kids grow up, and parents soon sing the same refrain as the kids sit transfixed by the virtual equivalent of LEGO: Minecraft.

Finding a way to monetize either LEGO or Minecraft is a bit difficult for the young enthusiast; combining both obsessions into a paying proposition would be a dream come true. [Mike Schropp] did it, and this Minecraft-themed LEGO computer case was the result. Intel wanted a LEGO case for their new NUC mini-PC motherboard, and as a sponsor of the Minefaire event, the case needed to be Minecraft themed.

[Mike] chose the block that any Enderman would choose: the basic grass block. Each of the ten cases he made for the show had about 1000 of the smallest LEGO pieces available, to recreate the texture of the grass block in all its faux 8-bit glory. The 4″ x 4″ (10cm x 10cm) 8th Gen NUC board was a great fit for the case, which included slots for ventilation and SD card access, plus pop-out covers to access the board’s ports. It’s not exactly a screamer, but playing Minecraft on a grass block made from LEGO bricks is probably worth the performance hit.

We’ve seen [Mike]’s work a time or two here, most recently with a full-scale LEGO rack-mount server. Our hats off to him for another fun and creative build, and for proving that you’re never too old to LEGO. Or Minecraft.

Lane Keeping RC Car Uses OpenCV

October 16, 2019 by Lewin Day 1 Comment

Automakers continue to promise that fully autonomous cars are around the corner, but we’re still not quite there yet. However, there are a broad range of driver assist technologies that have come to market in recent years, with lane keeping assist being one of them. [raja_961] decided to implement this technology on an RC car, using a Raspberry Pi.

A regular off-the-shelf RC car is used as the base of the platform, outfitted with two drive motors and a third motor used for the steering. Unfortunately, the car can only turn either full-left or full-right only, limiting the finesse of the steering. Despite this, the work continued. A Raspberry Pi 3 was fitted out with a motor controller and camera, and hooked up to the chassis. With everything laced up, a Python script is used along with OpenCV to run the lane-keeping algorithm.

[raja_961] does a great job of explaining the lane keeping methodology. Rather than simply invoking a library and calling it good, instead the Instructable breaks down each stage of how the algorithm works. Incoming images are converted to the HSL color system, before a series of operations is used to pick out the apparent slope of the lane lines. This is then used with a PID algorithm to guide the steering of the car.

It’s a comprehensive explanation of a basic lane-keeping algorithm, and a great place to start if you’re interested in learning about the technology. There’s plenty going on in the world of self-driving RC cars, you just need to know where to look! Video after the break.

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Repurposing A Toy Computer From The 1990s

October 14, 2019 by Tom Nardi 23 Comments

Our more youthful readers are fairly likely to have owned some incarnation of a VTech educational computer. From the mid-1980s and right up to the present day, VTech has been producing vaguely laptop shaped gadgets aimed at teaching everything from basic reading skills all the way up to world history. Hallmarks of these devices include a miserable monochrome LCD, and unpleasant membrane keyboard, and as [HotKey] found, occasionally a proper Z80 processor.

It started, as such things often do, with eBay. [HotKey] found that the second hand market is flooded with these decades-old educational gadgets, often selling for just a few bucks. As it turns out, children of the smartphone and tablet era don’t seem terribly interested in a “laptop” from 1991. At any rate, he ordered about a dozen different models and started tearing into them to see what made them tick.

He found that the VTech machines of around 20+ years old were using the Z80 processor, and what’s more, they shared a fairly standardized external cartridge interface for adding additional software or saving data. Upon attempting to dump some data from the cartridge port, [HotKey] discovered that it was actually connected to the computer’s main bus. He realized that with a custom designed cartridge, it should be able to take over the system and have it run his own code.

After more than a year of tinkering and talking to other hackers in the Z80 scene, [HotKey] has made some impressive headway. He’s not only created a custom cartridge that lets him load new code and connect to external devices, but he’s also added support for a few VTech machines to z88dk so that others can start writing their own C code for these machines. So far he’s created some very promising proof of concept programs such as a MIDI controller and serial terminal, but ultimately he hopes to create a DOS or CP/M like operating system that will elevate these vintage machines from simple toys to legitimate multi-purpose computers.

We’ve seen VTech hardware hacked in the past, but it’s generally been focused on the company’s more recent hardware such as the Linux-powered InnoTab. It will be interesting to see if these educational toys can fulfill some hacker’s dreams of having a cheap and portable box for Z80 tinkering.

This Hurricane Uses A Novel Technique

October 5, 2019 by Jenny List 16 Comments

You’ve probably heard of the brave pilots, the so-called ‘few’, that took to the air in their Supermarine Spitfires and saved the day during the Battle of Britain. It’s a story that contains a lot of truth, but as is so often the case, it masks a story with a bit more complexity. Those pilots did scramble across the airfields of Southern England back in the summer of 1940, but more of them went into battle behind the controls of a Hawker Hurricane than its more glamorous stablemate.

The Hurricane might have been eclipsed by the Spitfire in the public’s eye, but not for [Marius Taciuc], who’s made a fully-functional RC model of one. Normally that wouldn’t be worthy of our attention, but in this case he’s employed a rather fascinating construction technique. He’s recreated the doped-fabric skin of the original by 3D-printing the frame of the aircraft and covering it in heat-shrink film, making this a very rare bird indeed.

The video below takes us through the steps including the development of the frame in a CAD package based on a tracing of a 2D aircraft picture, fitting the film, and finally attempts at flight that are unfortunately foiled by inappropriate wheel choice. But the short flight and crash does demonstrate that this construction method is durable, which leads on to our interest in it. While it evidently makes a functional aircraft, there are other applications that could benefit from such a lightweight and strong combination of materials.

[Marius] actually created a model of the somewhat more photogenic Spitfire using a similar technique, though as far as we can tell, that one has remained grounded. Incidentally, these pages have been previously graced by Hurricanes of the non-PLA variety. Continue reading “This Hurricane Uses A Novel Technique” →