Author: Jenny List

3247 Articles

A Flip Digit Clock, Binary Style

October 8, 2024 by 7 Comments

Flip digit clocks are a prized piece of consumer electrical ephemera, providing as they do a digital display without significant electronics. Making your own flip digit display involves some drudgery in the production of all those flip cards, but how would it seem if the complexity was reduced? Go from base 10 to base 2 for example, and a binary flip digit display can be made from flip dot display parts. [Marcin Saj] has done just that, resulting in a timepiece that’s a few bits out of the ordinary.

Under the hood though it’s slightly more conventional, with the trusty ATmega328 and Arduino bootloader, whose software drives the dot electromagnets via a set of MOSFET drivers. It’s a nice project which if you want there’s a Kickstarter to buy one, but the files are also available from a GitHub repository if you’d like to have a go for yourself. Meanwhile you can see it in action in the video below the break.

We like this clock, as it’s different from the norm in Arduino clocks. It’s not however the first flip dot clock we’ve seen, this one has a full dot matrix display.

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Barbie’s Video Has Never Looked So Good

October 8, 2024 by 8 Comments

For those who missed it, there’s been something of a quiet revolution in the world of analogue video over the last year, due to the arrival of inexpensive “MiniDVR” devices. These little modules are a complete video recorder including battery, recording PAL or NTSC composite video and audio to SD card. They’ve become the box of choice for camcorder enthusiasts, but that’s not where the fun ends. [Max Vega] has taken a Barbie video camera toy from 2001 and added a MiniDVR to make it into a fully self-contained novelty camcorder. But this isn’t a simple case of duct-taping the DVR to the toy, instead it’s a comprehensive upgrade resulting in a device which could almost have been a real product.

The original toy had a small transmitter which could send over a short distance to a receiver that connected to a domestic VCR, so all that circuitry had to go. The camera itself is a small enough module in the fake lens assembly, with an easily identifiable output cable with the required composite signal. The video below the break steps through the proces of making the space for the MiniDVR module, and putting in extensions for all its buttons, and the SD card. Finally it has a new power supply module with an associated USB-C input, providing juice to both DVR and camera.

The result has what we can only describe as a pleasingly retro feel, in that it’s not of high quality and the colour is, well, Never The Same. But when a smartphone can record HD video that’s not the point, instead it’s there to be a retro toy, and in that it succeeds completely.

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The Piezoelectric Glitching Attack

October 7, 2024 by 18 Comments

Many readers will be familiar with the idea of a glitching attack, introducing electrical noise into a computer circuit in the hope of disrupting program flow and causing unexpected behaviour which might lead to hitherto unavailable access to memory or other system resources. [David Buchanan] has written a piece investigating glitching attacks on PC memory, and the tool he’s used is the ubiquitous piezoelectric lighter.

Attaching a short piece of wire to one of the lines on a SODIMM memory module, he can glitch a laptop at will with the lighter through the electromagnetic noise its discharge creates. It’s a cool trick, but the real meat of the write-up lies in his comprehensive description of how virtual memory works, and how a glitch can be used to break out of the “sandbox” of memory allocated to a particular process. He demonstrates it in a video which we’ve placed below the break, in which he gains root access and runs an arbitrary piece of code on a Linux laptop. It’s probable that not many of us have the inclination to do this for ourselves, but even so it’s fascinating to know how such an attack works.

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The Turing Machine Made Real, In LEGO

October 7, 2024 by 20 Comments

The British mathematician and pioneer of computing Alan Turing published a paper in 1936 which described a Universal Machine, a theoretical model of a computer processor that would later become known as a Turing Machine. Practical computers don’t quite follow the design of a Turing Machine, but if we are prepared to sacrifice its need for an infinitely long paper tape it’s quite possible to build one. This is what [The Bananaman] has done using LEGO as a medium, and if you’d like one for yourself you can even vote for it on the LEGO ideas website.

There’s a video for the project which we’ve placed below, and it goes into quite some detail on the various mechanisms required. Indeed for someone used to physical machinery it’s a better explanation through seeing the various parts than many paper explanations. Not for the first time we’re bowled over by what is possible through the use of the LEGO precision mouldings, this is a machine which would have been difficult and expensive to build in the 1930s by individually machining all its parts.

With just shy of six thousand supporters and a hefty 763 days left at time of writing, there’s plenty of time for it to garner support. But if you want one don’t delay, boost the project by voting for it early.

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Why Electric Trains Sound The Way They Do

October 5, 2024 by 20 Comments

If you’re a seasoned international rail traveler you will no doubt have become used to the various sounds of electric locomotives and multiple units as they start up. If you know anything about electronics you’ll probably have made the connection between the sounds and their associated motor control schemes, but unless you’re a railway engineer the chances are you’ll still be in the dark about just what’s going on. To throw light on the matter, [Z&F Railways] have a video explaining the various control schemes and the technologies behind them.

It’s made in Scotland, so the featured trains are largely British or in particular Scottish ones, but since the same systems can be found internationally it’s the sounds which matter rather than the trains themselves. Particularly interesting is the explanation of PWM versus pattern mode, the latter being a series of symmetrical pulses at different frequencies to create the same effect as PWM, but without relying on a single switching frequency as PWM does. This allows the controller to more efficiently match its drive to the AC frequency demanded by the motor at a particular speed, and is responsible for the “gear change” sound of many electric trains. We’re particularly taken by the sound of some German and Austrian locomotives (made by our corporate overlords Siemens, by coincidence) that step through the patterns in a musical scale.

Not for the first time we’re left wondering why electric vehicle manufacturers have considered fake internal combustion noises to make their cars sound sporty, when the sound of true electrical power is right there. The video is below the break.

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An Open Source Mirrorless Camera You’d Want To Use

October 5, 2024 by 18 Comments

Making a digital camera is a project that appears easy enough, but it’s one whose complexity increases depending on the level to which a designer is prepared to go. At the simplest a Raspberry Pi and camera module can be stuck in a 3D printed case, but in that case, the difficult work of getting the drivers and electronics sorted out has already been done for you.

At the other end of the scale there’s [Wenting Zhang]’s open source mirrorless digital camera project, in which the design and construction of a full-frame CCD digital camera has been taken back to first principles. To understand the scale of this task, this process employs large teams of engineers when a camera company does it, and while it’s taken a few years and the software isn’t perhaps as polished as your Sony or Canon, the fact it’s been done at all is extremely impressive.

Inside is a Kodak full-frame sensor behind the Sony E-mount lens, for which all the complex CCD timing and acquisition circuitry has been implemented. The brains of the show lie in a Xilinx Zynq ARM-and-FPGA in a stack of boards with a power board and the CCD board. The controls and battery are in a grip, and a large display is on the back of the unit.

We featured an earlier version of this project last year, and this version is a much better development with something like the ergonomics, control, and interface you would expect from a modern consumer camera. The screen update is still a little slow and there are doubtless many tweaks to come, but this really feels close to being a camera you’d want to try. There’s an assembly video which we’ve placed below the break, feast your eyes on it.

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HackFest Enschede: The Type Of Indoor Event We Wanted All Along

October 4, 2024 by 6 Comments

I’m sitting at a table writing this in the centre of a long and cavernous industrial building, the former print works of a local newspaper, I’m surrounded by hardware and software hackers working at their laptops, around me is a bustling crowd admiring a series of large projects on tables along the walls, and the ambient sound is one of the demoscene, chiptunes, 3D-printed guitars, and improbably hurdy-gurdy music. Laser light is playing on the walls, and even though it’s quite a journey from England to get here, I’m home. This is Hackfest Enschede, a two-day event in the Eastern Dutch city which by my estimation has managed the near-impossible feat of combining the flavour of both a hacker event and a maker faire all in one, causing the two distinct crowds to come together.

The Best Of Both Worlds, In One Place

To give an idea of what’s here it’s time for a virtual trip round the hall. I’ll start with the music, aside from the demosceners there’s Printstruments with a range of 3D-printedmusical instruments, and Nerdy Gurdy, as you may have guessed, that hacker hurdy-gurdy I mentioned. This is perhaps one of few places I could have seen a spontaneous jam session featuring a 3D-printed bass and a laser-cut hurdy-gurdy. Alongside them were the Eurorack synthesisers of Sound Force, providing analogue electronic sounds aplenty. Continue reading “HackFest Enschede: The Type Of Indoor Event We Wanted All Along” →