Software: It Is All In The Details

January 6, 2019 by 22 Comments

Who’s the better programmer? The guy that knows 10 different languages, or someone who knows just one? It depends. Programming is akin to math, or perhaps it is that we treat some topics differently than others which leads to misconceptions about what makes a good programmer, mathematician, or engineer. We submit that to be a great programmer is less about the languages you know and more about the algorithms and data structures you understand. If you know how to solve the problem, mapping it to a particular computer language should be almost an afterthought. While there are many places that you can learn those things, there is a lot more focus on how to write the languages,  C++ or Java or Python or whatever. We were excited, then, to see [Jeff Erickson] is publishing his algorithms book distilled from teaching at the University of Illinois, Urbana-Champaign for a number of years. The best part? You can read the preprint version online now and it will remain online even after the book goes to print.

When you were in school, you probably learned math in two ways: there was the mechanics (4×4=16) and then there were the word problems (Johnny has 10 candy bars and eats 4, how many are left?). Word problems are usually the bane of the student’s existence, yet they are much more realistic. Your boss has (probably) never come in your office and asked you what 147 divided by 12 is. If she did, you could hand her a calculator. The real value comes in being able to synthesize the right math for the right problem and — if you are lucky — gaining intuition about it (doubling the price will only increase profit by 10%). Software is pretty much the same, for example no one rushes into your cubicle and says “Quick! We need a for loop written!” You get a hazy set of requirements if you are lucky, and you then need to map that into something that computers can do. For that reason, we’ve always been more of a fan of learning about algorithms and data structures rather than specific language features.

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The Jookbox Is A Post-Modern Jukebox

January 6, 2019 by 21 Comments

The family of [Chris Patty] decided that their holiday gifts would have to be handmade. So, he decided to make something new for his father: a jukebox with a twist. Instead of a touchscreen or web interface, his jukebox uses swipe cards. To play a track, you find the card for the song you want to hear, swipe it, and the jukebox plays the requested track. The whole thing is built into a wooden box that hides its digital nature, which is built using a Raspberry Pi and a credit card stripe reader.

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Raspberry Pi Powers This Retro Chess Computer

January 6, 2019 by 15 Comments

If you imagine somebody playing chess against the computer, you’ll likely be visualizing them staring at their monitor in deep thought, mouse in hand, ready to drag their digital pawn into play. That might be accurate for the folks who dabble in the occasional match during their break, but for the real chess aficionados nothing beats playing on a real board with real pieces. Of course, the tricky part is explaining the whole corporeal thing to a piece of software on your computer.

Enter the “Chess Challenger” by [slash/byte]. Modeled after a commercial gadget of the same name from 1978, his retro-themed open hardware design utilizes the Raspberry Pi Zero and modern chess software to bring the vintage concept into the 21st century. With the Chess Challenger and a standard board, the player can face off in an epic battle of wits against the computer without risk of developing carpal tunnel. We can’t guarantee though that a few boards might not get flipped over in frustration.

The pocket sized chess computer uses a “sandwich” style construction which shows off the internals while still keeping things reasonably protected. All of the electronics are housed on the center custom PCB which features a HT16K33 driver for the dual LTP-3784E “starburst” LED displays, a MCP1642B voltage regulator, 16 TL3305 tactile switches for the keyboard, and a MCP73871 battery management chip for the 3.7 volt lithium-ion battery that powers the whole show. The Pi Zero itself connects to the board by way of the GPIO header, and is mechanically supported by the standoffs used to hold the device together.

On the software side of things, the Pi is running the mature Stockfish open source chess engine. In development now for over a decade, this GPL licensed package aims to deliver a world-class chess gameplay on everything from smartphones to desktop computers, and we’ve seen it pop up in a number of projects over the years. [slash/byte] has provided a ready to flash SD card image for the Raspberry Pi, and even provides detailed installation and setup instructions which guide you through some of the more thorny aspects of the setup such as getting the Pi running from a read-only operating system so that abrupt power cuts don’t clobber the filesystem.

Over the years, some of the most impressive projects we’ve seen revolved around playing chess, and this latest entry by [slash/byte] is no exception. Another example of the lengths the chess community will go to perfect the Game of Kings.

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A Quartet Of Drills Put The Spurs To This Electric Utility Vehicle

January 6, 2019 by 2 Comments

Low-slung body style. Four-wheel drive. All electric drivetrain. Turns on a dime. Neck-snapping acceleration. Leather seating surface. Is it the latest offering from Tesla? Nope; it’s a drill-powered electric utility vehicle, and it looks like a blast to drive.

Surprisingly, this isn’t a just-for-kicks kind of build. There’s actually a practical reason for the low form factor and long range of [Axel Borg]’s little vehicle. We’ll leave the back story to the second video below, but suffice it to say that this will be a smaller version of the crawler NASA used to roll rockets out to the launch pad, used instead to transport his insanely dangerous looking manned-multicopter. The running gear on this vehicle is the interesting bit: four hefty electric drills, one for each of the mobility cart wheels. The drills are powered by a large series-connected battery pack putting out 260V at full charge. The universal motors of the drills are fine with DC, and the speed of each is controlled via the PWM signals from a pair of cordless drills. The first video below shows [Axel] putting it through its paces; he didn’t hold back at all, but the vehicle kept coming back for more.

We know this cart is in service to another project, but we’d have a hard time concentrating on anything if we had the potential for that much fun sitting in the shop. Still, we hope that multirotor gets a good test flight soon, and that all goes well with it.

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Modular Feeders For SMD Component Tape

January 6, 2019 by 12 Comments

Making one of something is pretty easy, and making ten ain’t too bad. But what if you find yourself trying to make a couple of hundred of something on your home workbench? Suddenly, small timesavers start to pay dividends. For just such a situation, you may find these modular SMD tape feeders remarkably useful.

The tape feeders come in a variety of widths, to suit different size tapes. You’ve probably seen if you’ve ever ordered SMD components in quantity from Mouser, Digikey, et al. SMD components typically ship on large tape reels, which are machine fed into automated pick and place machines. However, if you’re doing it yourself in smaller quantities, having these manual tape feeders on your desk can be a huge help. Rather than having scraps of tapes scattered across the working surface, you can instead have them neatly managed at the edge of your bench, providing components as required.

The feeders are modular, so you can stack up as many as you need for a given job. Rails are provided to affix them to the relevant work surface. We’ve seen similar work before – like this 3D-printed bowl feeder for SMD parts.

 

Making Your Breadboard Projects A Little More Permanent

January 6, 2019 by 30 Comments

Many a budding electronics maker got their start not with a soldering iron, but with the humble breadboard. With its push connections, the breadboard enables electronics experimentation without requiring the specialised skill of soldering or any dangerous hot tools. What it lacks is a certain robustness that can make all but the simplest projects rather difficult to execute. [Runtime Micro] have shared a few tips on making things just a little more robust, however.

Applied correctly, these techniques have the added bonus of making a project neat, tidy, and easy to troubleshoot.

The fundamental principle behind this process is replacing point-to-point jumper wires with custom cables, made using 0.1″ pitch headers and wire-wrapping techniques. Other techniques include pinning down components with Blu-tack, and selecting components with the appropriate wire diameter to avoid them falling out of the breadboard’s spring clip contacts. There are also useful tips on using foam tape for appropriate strain relief.

While breadboards aren’t really suitable for projects dealing with high frequencies and can rapidly become unmanageable, these basic techniques should improve a project’s chance of success. These simple ways of improving connection quality and reducing the likelihood of things falling apart are likely to reduce frustration immensely.

However, once a maker has a taste for corralling electrons to do their bidding, soldering should be the first lesson on the agenda.

[Thanks to stockvu for the tip!]

This Machine Teaches Sign Language

January 6, 2019 by 5 Comments

Sign language can like any language be difficult to learn if you’re not immersed in it, or at least learning from someone who is fluent. It’s not easy to know when you’re making minor mistakes or missing nuances. It’s a medium with its own unique issues when learning, so if you want to learn and don’t have access to someone who knows the language you might want to reach for the next best thing: a machine that can teach you.

This project comes from three of [Bruce Land]’s senior electrical and computer engineering students, [Alicia], [Raul], and [Kerry], as part of their final design class at Cornell University. Someone who wishes to learn the sign language alphabet slips on a glove outfitted with position sensors for each finger. A computer inside the device shows each letter’s proper sign on a screen, and then checks the sensors from the glove to ensure that the hand is in the proper position. Two letters include making a gesture as well, and the device is able to track this by use of a gyroscope and compass to ensure that the letter has been properly signed. It appears to only cover the alphabet and not a wider vocabulary, but as a proof of concept it is very effective.

The students show that it is entirely possible to learn the alphabet reliably using the machine as a teaching tool. This type of technology could be useful for other applications as well, such as gesture recognition for a human interface device. If you want to see more of these interesting and well-referenced senior design builds we’ve featured quite a few, from polygraph machines to a sonar system for a bicycle.

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