Curated

76 Articles

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

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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The Seedy World Of Message Serialization

June 10, 2020 by 26 Comments

Look, I’ve been there too. First the project just prints debug information for a human in nice descriptive strings that are easy to understand. Then some tool needs to log a sensor value so the simple debug messages gain structure. Now your debug messages {{look like : this}}. This is great until a second sensor is added that uses floats instead of ints. Now there are sprinklings of even more magic characters between the curly braces. A couple days later and things are starting to look Turing complete. At some point you look up and realize, “I need a messaging serialization strategy”. Well you’ve come to the right place! Continue reading “The Seedy World Of Message Serialization” →

Bertha Benz Pushed The Automobile Toward Production

June 9, 2020 by 25 Comments

Who invented the automobile? The answer depends a little bit on your definition of the word. The first practical gas-powered carriage was built by Karl Benz, who later merged his company with Daimler Motor Group to form Mercedez-Benz.

Karl Benz was a design visionary whose first fascinations were with locomotives and bicycles. His 1886 Benz Patent Motorwagen was the first automobile to generate its own power, which was made with a two-stroke engine and transmitted to the rear axle by a pair of chains. He didn’t think it was ready for the road, and he was mostly right.

Bertha Benz, Karl’s wife and business partner, believed in her husband’s invention. She had been there since the beginning, and provided much of the funding for it along the way. If she hadn’t taken it out for a secret, illegal joyride, the Motorwagen may have never left the garage.

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3D Printing Nuclear Reactors For Fun And Profit

June 8, 2020 by 18 Comments

Over the past decades, additive manufacturing (AM, also known as 3D printing) has become increasingly common in manufacturing processes. While immensely helpful in the prototyping of new products by allowing for rapid turn-around times between design and testing, these days additive manufacturing is used more and more often in the production of everything from small production runs of custom enclosures to hard to machine components for rocket engines.

The obvious advantage of additive manufacturing is that they use generic equipment and common materials as input, without requiring expensive molds as in the case of injection molding, or extensive, wasteful machining of raw materials on a lathe, mill, and similar equipment. All of the manufacturing gets reduced to a 3D model as input, one or more input materials, and the actual device that converts the 3D model into a physical component with very limited waste.

In the nuclear power industry, these benefits haven’t gone unnoticed, which has led to 3D printed parts being developed for everything from keeping existing plants running to streamlining spent fuel reprocessing and even the printing of entire nuclear reactors.

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