Hack Your File Hierarchy With Johnny Decimal System (Dewey’s Older Brother)

February 2, 2019 by 24 Comments

Most of us have our fair share of digital debris. After all, with drives measured in one-million-million byte increments it’s tempting to never delete anything. The downside is you may never be able to find anything either. [Johnny Noble] must have gotten pretty fed up with clutter when he decided to formalize and publish his own numeric system for organizing everything he comes in contact with. It’s called Johnny Decimal and it’s actually pretty simple!

This is of course a play on words for the Dewey Decimal system. Dewey is one of a variety of information organization systems used by libraries to sort the books on their shelves. It’s based on moving books into sets of fixed, predefined categories which are uniform across all users of the Dewey. To locate a volume the user composes categories of increasing specificity to build a number which specifies the approximate space a particular book should live in. Each individual volume has a slightly more verbose assigned number which includes the author’s name to reduce confusion in cases where there are multiple works. Wikipedia has an instructive example which you can see here.

Johnny Decimal

Johnny Decimal works similarly but [Johnny] has a specific method he’s devised for the user to create their own categories with somewhat less specificity than Dewey. This makes it less onerous for the user to adapt to their needs, and if it’s easier to use it’s more likely to be used. I won’t spoil the process here, go read his site for instructions.

Ok so why bother? [Johnny] hints at it, but part of the point is to force the user to think about organization in the first place. With no system and an endless torrent of incoming files it’s easy to end up with the giant “~/Downloads” of doom and never improve from there. But with a clearly defined system (which is easy to execute!) the bar to improve things gets much lower. Certainly the thought of a well-organized file system gives us the shivers!

If you’re interested in implementing it in your own systems, the Johnny Decimal site has many pages devoted to explaining how to put together areas and categories, how to handle running out of buckets, the process for developing your own system, and more. If you try it and have luck, send us a note! We’d love to hear about anything you discover. If you’ll excuse us, we’re off to go fix up our parts bins with a marker and some sticky notes.

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Never Mind The Sheet Music, Here’s Spreadsheet Music

February 2, 2019 by 7 Comments

Nothing says Rockstar Musician Lifestyle like spreadsheet software. Okay, we might have mixed up the word order a bit in that sentence, but there’s always Python to add some truth to it. After all, if we look at the basic concept of MIDI sequencers, we essentially have a row of time-interval steps, and depending on the user interface, either virtual or actual columns of pitches or individual instruments. From a purely technical point of view, spreadsheets and the like would do just fine here.

Amused by that idea, [Maxime] wrote a Python sequencer that processes CSV files that works with both hardware and software MIDI synthesizers. Being Python, most of the details are implemented in external modules, which makes the code rather compact and easy to follow, considering it supports both drums and melody tracks in the most common scales. If you want to give it a try, all you need is the python-rtmidi and mido module, and you should be good to go.

However, if spreadsheets aren’t your thing, [Maxime] has also a browser-based sequencer project with integrated synthesizer ongoing, with a previous version of it also available on GitHub. And in case software simply doesn’t work out for you here, and you prefer a more hands-on experience, don’t worry, MIDI sequencers seem like an unfailing resource for inspiration — whether they’re built into an ancient cash register, are made entirely out of wood, or are built from just everything.

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Cheap ESP32 Webcam

February 2, 2019 by 49 Comments

Looking for a cheap way to keep an eye on something? [Kevin Hester] pointed us to a way to make a WiFi webcam for under $10. This uses one of the many cheap ESP32 dev boards available, along with the Internet of Things platform PlatformIO and a bit of code that creates an RTSP server. This can be accessed by any software that supports this streaming protocol, and a bit of smart routing could put it on the interwebs. [Kevin] claims that the ESP32 camera dev boards he uses can be found for less than $10, but we found that most of them cost about $15. Either way, that’s cheaper than most commercial streaming cameras.

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Create An Aurora Of Your Own

February 2, 2019 by 14 Comments

Throughout our day-to-day experiences, we come across or make use of many scientific principles which we might not be aware of, even if we immediately recognize them when they’re described. One such curiosity is that of caustics, which refers not only to corrosive substances, but can also refer to a behavior of light that can be observed when it passes through transparent objects. Holding up a glass to a light source will produce the effect, for example, and while this is certainly interesting, there are also ways of manipulating these patterns using lasers, which makes an aurora-like effect.

The first part of this project is finding a light source. LEDs proved to be too broad for good resolution, so [Neuromodulator] pulled the lasers out of some DVD drives for point sources. From there, the surface of the water he was using to generate the caustic patterns needed to be agitated, as the patterns don’t form when passing through a smooth surface. For this he used a small speaker and driver circuit which allows precise control of the ripples on the water.

The final part of the project was fixing the lasers to a special lens scavenged from a projector, and hooking everything up to the driver circuit for the lasers. From there, the caustic patterns can be produced and controlled, although [Neuromodulator] notes that the effects that this device has on film are quite different from the way the human eye and brain perceive them in real life. If you’re fascinated by the effect, even through the lens of the camera, there are other light-based art installations that might catch your eye as well.

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Custom Jig Makes Short Work Of Product Testing

February 2, 2019 by 19 Comments

When you build one-off projects for yourself, if it doesn’t work right the first time, it’s a nuisance. You go back to the bench, rework it, and move on with life. The equation changes considerably when you’re building things to sell to someone. Once you take money for your thing, you have to support it, and anything that goes out the door busted is money out of your pocket.

[Brian Lough] ran into this fact of life recently when the widget he sells on Tindie became popular enough that he landed an order for 100 units. Not willing to cut corners on testing but also not interested in spending days on the task, he built this automated test jig to handle the job for him. The widget in question is the “Power BLough-R”, a USB pass-through device that strips the 5-volt from the line while letting the data come through; it’s useful for preventing 3D-printers from being backfed when connected to Octoprint. The tester is very much a tactical build, with a Nano in a breakout board wired to a couple of USB connectors. When the widget is connected to the tester, a complete series of checks make sure that there are no wiring errors, and the results are logged to the serial console. [Brian] now has complete confidence that each unit works before going out the door, and what’s more, the tester shaved almost a minute off each manual test. Check in out in action in the video below.

We’ve featured quite a few of [Brian]’s projects before. You may remember his Tetris-themed YouTube subscriber counter, or his seven-segment shoelace display.

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This Creepy Skull Shows Time With Its Eyes

February 1, 2019 by 1 Comment

Sometimes you have an idea, and despite it not being the “right” time of year you put a creepy skull whose eyes tell the time and whose jaw clacks on the hour into a nice wooden box for your wife as a Christmas present. At least, if you’re reddit user [flyingalbatross1], you do!

The eyes are rotated using 360 degree servos, which makes rotating the eyes based on the time pretty easy. The servos are connected to rods that are epoxied to the spheres used as eyes. Some water slide iris decals are put on the eyes offset from center in order to point in the direction of the minutes/hours. An arduino with a real time clock module keeps track of the time and powers the servos.

Check out the video after the break:

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Portable Ham Antenna Gets A Workout

February 1, 2019 by 13 Comments

Ham radio isn’t just one hobby. It is a bunch of hobbies ranging from chatting to building things, bouncing signals off the moon, and lots of things in between. Some of these specialties, such as supporting disaster relief or putting odd locations “on the air”, require portable operation. To encourage disaster readiness, hams participate in Field Days which is a type of contest that encourages simulated emergency conditions. So how do you erect an antenna when you just have a few hours to set up a temporary station? [KB9VBR] shows how he and his friend used a Chameleon Emcomm III portable HF antenna for Winter Field Day. You can see the video review, below.

Unlike some portable antennas, this one is almost 100 feet of wire (73 feet of radiator and a 25 foot counterpoise). The entire affair is meant to be put up and taken down repeatedly.

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