Pit Your Wits Against British Spooks

December 13, 2021 by Jenny List 13 Comments

The festive season is upon us, and for Brits of a technical bent that means it’s time for the GCHQ Christmas Challenge. Sent out annually as part of the Christmas card from the UK’s intelligence centre, this is a chance for would-be spooks to pit their wits against some of the nation’s cleverest cryptologists whose work you’ll never have heard of.

This year the puzzle is aimed at those with a secondary school education, in the hope of fostering an interest in maths and science in younger people. It’s a series of puzzles of ascending difficulty, but don’t be lulled into a false sense of security by the earlier ones being easy, to complete the set will still require some brain power.

We’re guessing that as in previous years, this puzzle will garner a significant quantity of entries. It’s a successful public relations exercise from the agency which like all such organisations has felt its fair share of controversy in its time. There may thus be readers who regard it with some suspicion, but it’s fair to say it’s not the only such popular exercise from a govenment agency. If meanwhile you fancy a bit of GCHQ history, we caught their Science Museum exhibition back in 2019.

Never Lose A Piece With 3D Printed Sliding Puzzles

August 28, 2021 by Jim Heaney 6 Comments

Have you ever been about to finish a puzzle, when suddenly you realize there are more holes left than you have pieces? With [Nikolaos’s] 3D printed sliding puzzles, this will be a problem of the past!

An image showing the sliding dovetails of the puzzle — The dovetails, integrated into each piece, keep the puzzle together but still allows pieces to move.

The secret of the puzzle is in the tongue and groove system that captures the pieces while allowing them to slide past each other and along the puzzle’s bezel. The tongues are along the top and right sides of the pieces shown here, with the grooves along the left and bottom. There is only one empty spot on the board, so the player must be methodical in how they move pieces to their final destinations. See this in action in the video after the break.

[Nikolaos] designed the puzzle in Fusion 360, and used this as an opportunity to practice with parameters. He designed the model in such a way that any size puzzle could be generated by changing just 2 variables. Once the puzzle is the proper size, the image is added by importing and extruding an SVG.

Another cool aspect of these puzzles is that they are print-in-place, meaning that when the part is removed from the 3D printer, it is ready to use and fully assembled. No need to remove support material or bolt and glue together multiple components. Print-in-place is useful for more than just puzzles, you could also use this technique to 3D print wire connectors!

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Jigsaw Puzzle Lights Up With Each Piece

July 1, 2021 by Bryan Cockfield 5 Comments

Putting the last piece of a project together and finally finishing it up is a satisfying feeling. When the last piece of a puzzle like that is a literal puzzle, though, it’s even better. [Nadieh] has been working on this jigsaw puzzle that displays a fireworks-like effect whenever a piece is placed correctly, using a lot of familiar electronics and some unique, well-polished design.

The puzzle is a hexagonal shape and based on a hexagonally symmetric spirograph, with the puzzle board placed into an enclosure which houses all of the electronics. Each puzzle piece has a piece of copper embedded in a unique location so when it is placed on the board, the device can tell if it was placed properly or not. If it was, an array of color LEDs mounted beneath a translucent diffuser creates a lighting effect that branches across the entire board like an explosion. The large number of pieces requires a multiplexer for the microcontroller, an ATtiny3216.

This project came out of a FabAcademy, so the documentation is incredibly thorough. In fact, everything on this project is open sourced and available on the project page from the code to the files required for cutting out the puzzle pieces and the enclosure. It’s an impressive build with a polish we would expect from a commercial product, and reminds us of an electrified jigsaw puzzle we saw in a previous build.

Thanks to [henk] for the tip!

Planetary Escape (-Room In A Box)

March 19, 2021 by Brian McEvoy 10 Comments

The trick to a fun escape room is layers. For [doktorinjh]’s Spacecase, you start with an enigmatic aluminum briefcase and a NASA drawstring backpack. A gamemaster reads the intro speech to set the mood, and you’re ready to start your escape from the planet. The first layer is the backpack with puzzles you need to solve to get into the briefcase. In there, you discover a hidden compartment and enough sci-fi references to put goofy smiles on our faces. We love to see tools reused as they are in one early puzzle, you use a UV LED to reveal a hidden message, but that light also illuminates puzzle clues later.

All the tech in Spacecase makes it a wonder of mixed media. The physical layer has laser engraved wood featuring the font from the 1975 NASA logo, buttons, knobs, LEDs, toggle switches, and a servo. Beneath the visible faceplate is an RGB sensor, audio player, speaker, and at the center is an Arduino MEGA. We’d love to get our hands on Spacecase for a game, and we’re inspired to pull out all the stops and build games with our personal touches. Maybe something with a mousetrap.

This isn’t the first escape room hardware we’ve seen and [doktorinjh] similarly made a bomb ~~diffusing~~ defusing game.

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Automation With A New Twist

August 29, 2020 by Brian McEvoy 4 Comments

Turning on a lightbulb has never been easier. You can do it from your mobile. Voice activation through home assistants is robust. Wall switches even play nicely with the above methods. It was only a matter of time before someone decided to make it fun, if you consider a Rubik’s cube enjoyable. [Alastair Aitchison] at Playful Technology demonstrated that it is possible to trigger a relay when you match all the colors. Video also after the break.

The cube does little to obfuscate game data, so in this scope, it sends unencrypted transmissions. An ESP32 with [Alastair]’s Arduino code, can track each movement, and recognize a solved state. In the video, he solves the puzzle, and an actuator releases a balloon. He talks about some other cool things this could do, like home automation or a puzzle room, which is in his wheelhouse judging by the rest of his YouTube channel.

We would love to see different actions perform remote tasks. Twisting the top could set a timer for 1-2-3-4-5 minutes, while the bottom would change the bedroom lights from red-orange-yellow-green-blue-violet. Solving the puzzle should result in a barrage of NERF darts or maybe keep housemates from cranking the A/C on a whim.

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Passing The Time By Reading The Time

May 14, 2020 by Sven Gregori 4 Comments

Binary clocks are a great way to confuse your non-technical peers when they ask the time from you — not that knowing about the binary system would magically give you quick reading skills of one yourself. In that case, they’re quite a nice little puzzle, and even a good alternative to the quarantine clocks we’ve come across a lot recently, since you can simply choose not to bother trying to figure out the exact time. But with enough training, you’ll eventually get the hang of it, and you might be in need for a new temporal challenge. Well, time to level up then, and the Cryptic Wall Clock built by [tomatoskins] will definitely keep you busy with that.

Example of the clock showing 08:44:47 — Diagram of the clock showing 08:44:47

If you happen to be familiar with the Mengenlehreuhr in Berlin, this one here uses the same concept, but is built in a circular shape, giving it more of a natural clock look. And if you’re not familiar with the Mengenlehreuhr (a word so nice, we had to write it twice), the way [tomatoskins]’ clock works is to construct the time in 24-hour format by lighting up several sections in the five LED rings surrounding a center dot.

Starting from the innermost ring, each section of the rings represent intervals of 5h, 1h, 5m, 1m, and 2s, with 4, 4, 11, 4, and 29 sections per ring respectively. The center dot simply adds an additional second. The idea is to multiply each lit up section by the interval it represents, and add the time together that way. So if each ring has exactly one section lit up, the time is 06:06:02 without the dot, and 06:06:03 with the dot — but you will find some more elaborate examples in his detailed write-up.

This straightforward and yet delightfully unintuitive concept will definitely keep you scratching your head a bit, though you can always go weirder with the Roman numerals palm tree clock for example. But don’t worry, [tomatoskins] has also a more classic, nonetheless fascinating approach in his repertoire.

Hackaday Links: October 27, 2019

October 27, 2019 by Dan Maloney 13 Comments

A year ago, we wrote about the discovery of treasure trove of original documentation from the development of the MOS 6502 by Jennifer Holdt-Winograd, daughter of ~~the late~~ Terry Holdt, the original program manager on the project. Now, Ms. Winograd has created a website to celebrate the 6502 and the team that built it. There’s an excellent introductory video with a few faces you might recognize, nostalgia galore with period photographs that show the improbable styles of the time, and of course the complete collection of lab notes, memos, and even resumes of the team members. If there were a microchip hall of fame – and there is – the 6502 would be a first-round pick, and it’s great to see the history from this time so lovingly preserved.

Speaking of the 6502, did you ever wonder what the pin labeled SO was for? Sure, the data sheets all say pin 38 of the original 40-pin DIP was the “Set Overflow” pin, an active low that set the overflow bit in the Processor Status Register. But Rod Orgill, one of the original design engineers on the 6502, told a different story: that “SO” was the initials of his beloved dog Sam Orgill. The story may be apocryphal, but it’s a Good Doggo story, so we don’t care.

You may recall a story we ran not too long ago about the shortage of plutonium-238 to power the radioisotope thermoelectric generators (RTGs) for deep-space missions. The Cold War-era stockpiles of Pu-238 were running out, but Oak Ridge National Laboratory scientists and engineers came up with a way to improve production. Now there’s a video showing off the new automated process from the Periodic Videos series, hosted by the improbably coiffed Sir Martyn Poliakoff. It’s fascinating stuff, especially seeing workers separated from the plutonium by hot-cells with windows that are 4-1/2 feet (1.4 meters) thick.

Dave Murray, better known as YouTube’s “The 8-Bit Guy”, can neither confirm nor deny the degree to which he participated in the golden age of phone phreaking. But this video of his phreaking presentation at the Portland Retro Gaming Expo reveals a lot of suspiciously detailed knowledge about the topic. The talk starts at 4:15 or so and is a nice summary of blue boxes, DTMF hacks, war dialing, and all the ways we curious kids may or may not have kept our idle hands busy before the Interwebz came along.

Do you enjoy a puzzle? We sure do, and one was just laid before us by a tipster who prefers to stay anonymous, but for whom we can vouch as a solid member of the hacker community. So no malfeasance will befall you by checking out the first clue, a somewhat creepy found footage-esque video with freaky sound effects, whirling clocks, and a masked figure reading off strings of numbers in a synthesized voice. Apparently, these clues will let you into a companion website. We worked on it for a bit and have a few ideas about how to crack this code, but we don’t want to give anything away. Or more likely, mislead anyone.

And finally, if there’s a better way to celebrate the Spooky Season than to model predictions on how humanity would fare against a vampire uprising, we can’t think of one. Dominik Czernia developed the Vampire Apocalypse Calculator to help you decide when and if to panic in the face of an uprising of the ~~undead~~ metabolically ambiguous. It supports several models of vampiric transmission, taken from the canons of popular genres from literature, film, and television. The Stoker-King model makes it highly likely that vampires would replace humans in short order, while the Harris-Meyer-Kostova model of sexy, young vampires is humanity’s best bet except for having to live alongside sparkly, lovesick vampires. Sadly, the calculator is silent on the Whedon model, but you can set up your own parameters to model a world with Buffy-type slayers at your leisure. Or even model the universe of The Walking Dead to see if it’s plausible that humans are still alive 3599 days into the zombie outbreak.