Curated

76 Articles

Hackaday’s finest original content articles curated by the Hackaday editors

Samsung’s Leap Month Bug Teaches Not To Skimp On Testing

June 15, 2020 by 23 Comments

Date and time handling is hard, that’s an ugly truth about software development we’ll all learn the hard way one day. Sure, it might seem like some trivial everyday thing that you can easily implement yourself without relying on a third-party library. I mean, it’s basically just adding seconds on top of one another, roll them over to minutes, and from there keep rolling to hours, days, months, up until you hit the years. Throw in the occasional extra day every fourth February, and you’re good to go, right?

Well, obviously not. Assuming you thought about leap years in the first place — which sadly isn’t a given — there are a few exceptions that for instance cause the years 1900 and 2100 to be regular years, while the year 2000 was still a leap year. And then there’s leap seconds, which occur irregularly. But there are still more gotchas lying in wait. Case in point: back in May, a faulty lunar leap month handling in the Chinese calendar turned Samsung phones all over China into bricks. And while you may not plan to ever add support for non-Gregorian calendars to your own project, it’s just one more example of unanticipated peculiarities gone wild. Except, Samsung did everything right here.

So what happened?

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Engineers Develop A Brain On A Chip

June 13, 2020 by 21 Comments

Our abilities to multitask, to quickly learn complex maneuvers, and to instantly recognize objects even as infants are just some of the ways that human brains make use of our billions of synapses. Biologically, our brain requires fluid-filled cavities, nerve fibers, and numerous other cells and connections in order to function. This isn’t the case with a new kind of brain recently announced by a team of MIT engineers in Nature Nanotechnology. Compared to the size of a typical human brain, this new “brain-on-a-chip” is able to fit on a piece of confetti.

When you take a look at the chip, it is more similar to tiny metal carving than to any neurological organ. The technology used to design the chip is based on memristors – silicon-based components that mimic the transmissions of synapses. A concatenation of “memory” and “resistor”, they exist as passive circuit elements that retain a relationship between the time integrals of current and voltage across an element. As resistance varies, tiny read charges are able to access a history of applied voltage. This can be accomplished by hysteresis and other non-linear properties of passive circuitry.

These properties can be best observed at nanoscale levels, where they aren’t dwarfed by other electronic and field effects. A tiny positive and negative electrode are separated by a “switching medium”, or space between the two electrodes. Voltage applied to one end causes ions to flow through the medium, forming a conduction channel to the other end. These ions make up the electrical signal transmitted through the circuit.

In order to fabricate these memristors, the researchers used alloys of silver for the positive electrode, and copper alongside silicon for the negative electrode. They sandwiched the two electrodes along an amorphous medium and patterned this on a silicon chip tens of thousands of times to create an array of memristors. To train the memristors, they ran the chips through visual tasks to store images and reproduce them until cleaner versions were produced. These new devices join a new category of research into neuromorphic computing – electronics that function similar to the way the brain’s neural architecture operates.

The opportunity for electronics that are capable of making instantaneous decisions without consulting other devices or the Internet spell the possibility of portable artificial intelligence systems. Though we already have software systems capable of simulating synaptic behavior, developing neuromorphic computing devices could vastly increase the capability of devices to do tasks once thought to belong solely to the human brain.

How CERN Made High Quality Electronics In The 1970s

June 12, 2020 by 37 Comments

We’re suckers for some retro electronics here at Hackaday, so we were fascinated when Daniel Valuch wrote to us with some pictures of his findings in his CERN lab’s archive. He works on Linear Accelerator 3, which has had an extended downtime after many decades of continuous operation, for major upgrades and overhauls. Part of the upgrade involves the removal of electronic assemblies dating back as far as the 1970s, and he’s shared his fascination with them as he trawls through dusty filing cabinets in the lab basement.

What it reveals is a world before the CAD and microcontrollers we know, instead here are circuits using the electronic building blocks of logic gates, discretes, and op-amps. PCBs are laid out not with the KiCad that CERN are famous in our community for today, but on acetate, with transfers and tape. A ground plane is even hand-carved from a red sheet. Oddly though it isn’t a world without CNC, because in the pouch with a design from 1974 is a roll of punched paper tape. If you have ever pondered the “Numerical” in “Computer Numerical Control”, here are the numbers in physical form.

For those of us who were trained in this type of electronic design, the convenience of a PCB CAD package and a professionally-made PCB at the click of a mouse is nothing short of miraculous. But seeing personally laid boards of this quality reminds us that seeing the hand of the designer in them is something few engineers today (with the possible exception of Boldport) manage to recreate.

Binary Math Tricks: Shifting To Divide By Ten Ain’t Easy

June 12, 2020 by 52 Comments

On small CPUs, you often don’t have a multiply or divide instruction. Of course, good programmers know that shifting right and left will multiply or divide by a power of two. But there are always cases where you need to use something that isn’t a power of two. Sometimes you can work it out for multiplication.

For example, multiplying by 10 is common when dealing with conversion between binary and decimal. But since 10n is equal to 8n+2n, you can express that as a bunch of left shift three times to multiply by eight, adding that value to your original value shifted left once to multiply by two.

But division is a different problem. n/10 does not equal n/8-n/2 or anything else simple like that. The other day a friend showed me a very convoluted snippet of code on Stack Overflow by user [realtime] that divides a number by 10 and wanted to know how it worked. It is pretty straightforward if you just stick with the math and I’ll show you what I mean in this post. Turns out the post referenced the venerable Hacker’s Delight book, which has a wealth of little tricks like this.

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A Beginner’s Guide To Lithium Rechargeable Batteries

June 11, 2020 by 42 Comments

Batteries were once heavy, awkward things, delivering only a limp amount of current for their size and weight. Thankfully, over time, technology has improved, and in 2020, we’re blessed with capable, high-power lithium polymer batteries that can provide all the power your mobile project could possibly need. There are some considerations one must make in their use however, so read on for a primer on how to properly use LiPos in your project!

So Many Types!

With the first commercial lithium-ion battery entering the market in 1991, the (nearly) 30 years since have seen rapid development. This has led to a proliferation of different technologies and types of battery, depending on construction and materials used. In order to treat your batteries properly, it’s important to know what you’ve got, so paying attention to this is critical. Continue reading “A Beginner’s Guide To Lithium Rechargeable Batteries” →

Quantum Computing And The End Of Encryption

June 11, 2020 by 58 Comments

Quantum computers stand a good chance of changing the face computing, and that goes double for encryption. For encryption methods that rely on the fact that brute-forcing the key takes too long with classical computers, quantum computing seems like its logical nemesis.

For instance, the mathematical problem that lies at the heart of RSA and other public-key encryption schemes is factoring a product of two prime numbers. Searching for the right pair using classical methods takes approximately forever, but Shor’s algorithm can be used on a suitable quantum computer to do the required factorization of integers in almost no time.

When quantum computers become capable enough, the threat to a lot of our encrypted communication is a real one. If one can no longer rely on simply making the brute-forcing of a decryption computationally heavy, all of today’s public-key encryption algorithms are essentially useless. This is the doomsday scenario, but how close are we to this actually happening, and what can be done?

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Surviving The Pandemic As A Hacker: Making A Mask Of Your Very Own

June 10, 2020 by 25 Comments

As the COVID-19 pandemic has continued along its way through the world, our community has responded as it always does, by designing and making things intended to solve the problems thrown up by the situation we find ourselves in. Much of this effort has gone into the production of PPE to plug the gap and many essential staff have been protected by maker-provided equipment, while the remainder of the effort has produced a wide array of clever designs for COVID-related items.

With curves flattened in many areas, Governments around the world are now encouraging the wearing of face masks in everyday social interactions. The purpose of mask for the general public is for droplet catching rather than virus filtering, and home made masks easily accomplish this. So let’s take a look at what you need to know about making a mast of your very own.

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