LED Matrix Hack Chat

Join us on Wednesday, June 9 at noon Pacific for the LED Matrix Hack Chat with Garrett Mace!

It’s pretty amazing how quickly light-emitting diodes went from physics lab curiosity to a mainstream commodity product made in the millions, if not billions. Everything about LEDs has gotten better, smaller, and cheaper over the years, going from an “any color you want as long as it’s red” phase to all the colors of the rainbow and beyond in a relatively short time. LEDs have worked their way into applications that just didn’t seem likely not that long ago, like architectural lighting, automotive applications, and even immense displays covering billboards, buildings, and sporting venues with multicolor, high-resolution displays.

It’s that latter application that seems to have provided a boon to electronics hobbyists, in the form of cheap and plentiful LED matrix modules. These are easily sourced at the usual places, and with their tightly packed pinpoints that can show any color at any intensity, they have a ton of fun and useful applications for the hacker. But how exactly do you put them to use? Usually the electronics end is pretty straightforward, but some of the math involved in figuring out how to address all these LEDs can be a little mind-bending.

To help us sort all this out, Garrett Mace will drop by the Hack Chat. You’ve probably seen Garrett’s cool LED matrix shades, which have gone through a ton of revisions and are a much-copied fashion accessory among the cool hackers. They look simple, but there are tricks to making them work right, and Garrett will share his secrets. Come with your questions on putting LED matrix modules to work, especially those odd-size modules and strange arrangements that defy simple Cartesian coordinates.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, June 9 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

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Hackaday Links: June 6, 2021

There are a bunch of newly minted millionaires this week, after it was announced that Stack OverFlow would be acquired for $1.8 billion by European tech investment firm Prosus. While not exactly a household name, Prosus is a big player in the Chinese tech scene, where it has about a 30% stake in Chinese internet company Tencent. They trimmed their holdings in the company a bit recently, raising $15 billion in cash, which we assume will be used to fund the SO purchase. As with all such changes, there’s considerable angst out in the community about how this could impact everyone’s favorite coding help site. The SO leadership are all adamant that nothing will change, but only time will tell.

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Wreck Your Mail Before You Check Your Mail

Every five years or so, I think it’s time to review my e-mail flow. (Oh no!) I run my own mail server, and you should too, but this means that I get to figure out managing and searching and archiving and indexing it all by myself. (Yippee!)

And I’ll be honest — sometimes I’m a bit of a luddite. I actually, literally have been using Mutt, or its derivative NeoMutt for maybe fifteen years, after a decade or so of mouse-intensive graphical mail readers. If e-mail is about typing words, and maybe attaching the occasional image, nothing beats a straight-up text interface. But what a lot of these simple mail clients lack is good search. So I decided to take that seriously.

Notmuch is essentially an e-mail database. It’s an e-mail searcher, tagger, and indexer, but it’s not much else. The nice thing is that it’s brutally fast. Searches and extraction of tagged subsets are faster than sending the same data back and forth to the Big G, and I have a ton more flexibility. It’s awesome. Of course good ol’ Mutt can work with Notmuch. Everything can. It’s Linux/UNIX. Continue reading “Wreck Your Mail Before You Check Your Mail”

Hackaday Podcast 121: Crazy Bikes, DIY Flip Dots, EV Mountain Climbing, And Trippy Tripterons

Hackaday editors Mike Szczys and Elliot Williams discuss a great week of hardware hacks. Two delightful mechanical hacks focus on bicycles: one that puts a differential on the front fork, and the other a flywheel between the knees. Elliot was finally impressed by something involving AI — a machine-learning guitar pedal. You’ve heard of a delta bot? The tripteron is similar but with a single rail for the three arms. After a look at flip dots, tiny robots, and solar air planes we close the show geeking out about racing electric vehicles up a hill and stories of the hardware that has made closed captions possible.

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (55 MB or so.)

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This Week In Security: Ransomware, WeLock, And Amazon Arbitration

Another week of ransomware, and this time it’s the beef market that’s been shut down, due to a crippling infrastructure attack out of Russia — but hold up, it’s not that simple. Let’s cover the facts. Some time on Sunday, May 30, JBS USA discovered a ransomware attack against their systems. It seems that their response team did exceptionally well, pulling the plug on affected machines, and starting recovery right away. By Wednesday, it was reported that most of their operations were back in action.
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How To Get Into Cars: Ice Racing Mods

Typically, when it comes to inclement weather, ice is the worst of the worst of driving conditions. Regular tyres have little to no grip in such situations, and accidents are common. However, some choose to laugh at such challenges, and take to racing out on frozen lakes and rivers. The sport of ice racing can be a demanding one, though, so you’ll need to prep your car appropriately. Here’s how.

Ice, Ice, Baby

The highest tier of ice racing is the Andros Trophy, conducted in France each year. Competitors in the top class compete in mid-engined V6-powered cars with AWD and four-wheel steering.

Ice racing is largely limited to colder climates where lakes, rivers, or even actual racetracks freeze over in the winter. While some limited ice racing does occur indoors on skating rinks, it’s largely limited to motorcycles and ATVs because such facilities are just too small for cars.

The weather-dependent and esoteric nature of ice racing means that it exists at the fringes of organised motorsport, with most events being community-run at the grassroots level. Often, new competitors will start in a “run-what-you-brung” class, with unmodified street cars competing in limited or no-contact events, such as time trials or drag races. Higher tiers then generally necessitate more serious preparation and safety equipment, such as rollcages and fire extinguishers, and competitive door-to-door racing on larger tracks. However, some professional competitions do exist, running bespoke tube-framed cars built for purpose. The most notable of these is the Andros Trophy, held in the French Alps and run by the namesake jam company. Continue reading “How To Get Into Cars: Ice Racing Mods”

Anti-Gravity, Time Travel, And Teleportation: Dr. Hamming Gives Advice

You may not know the name [Richard Hamming], but you definitely use some of his work. While working for Bell Labs, he developed Hamming codes — the parent of a class of codes that detect, and sometimes correct, errors in everything from error-correcting memory to hard drives. He also worked on the Manhattan Project and was a lecturer at the Naval Postgraduate school.

Turns out [Hamming] has an entire class from the 1990s on YouTube and if you are interested in coding theory or several other topics, you could do worse than watch some of them. However, those videos aren’t what attracted me to the lectures. As the last lecture of his course, [Hamming] used to give a talk called “You and Your Research” and you can see one of the times he delivered it in the video below. You might think that it won’t apply to you because you aren’t a professional academic or researcher, but don’t be too quick to judge.

Turns out, [Hamming’s] advice — even by his own admission — is pretty general purpose for your career or even your life. His premise: As far as we know, you have one life to live, so why shouldn’t it be a worthwhile one by your definition of worthwhile.

Along the way, he has an odd combination of personal philosophy, advice for approaching technical problems, and survival skills for working with others. If you are in the field, you’ll probably recognize at least some of the names he drops and you’ll find some of this technical advice useful. But even if you aren’t, you’ll come away with something. Some of it seems like common sense, but it is different, somehow, to hear it spoken out loud. For example:

If you don’t work on important problems, it’s not likely that you’ll do important work.

One piece of technical advice? Don’t waste time working on problems you have no way to attack. He points out that anti-gravity, time travel, and teleportation would be very lucrative. But why work on them when there appears to be no way to even remotely accomplish them today. Well, at least when he said that. There has been a little progress on a form of teleportation, but that wasn’t what he was talking about anyway.

While not a hack in the traditional sense, examining your life, career, and technical research to improve your own effectiveness is something to take seriously. We were hoping he would throw in a joke about error-correcting your career, but unless we blinked, no such luck.

Hamming’s work on block codes was followed about ten years later by the Reed-Solomon code which is found nearly everywhere now. Hamming is also associated with the term “hamming distance,” something we talked about when discussing Gray code.

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