Author: Sven Gregori

143 Articles

Rock Out With Toilet Paper Rolls

April 21, 2020 by 16 Comments

Singing in the shower is such a common phenomenon, rarely anyone ever bats an eye about it. Singing in the toilet on the other hand is probably going to raise an eyebrow or two, and it’s not for nothing that the Germans euphemistically call it “stilles Örtchen”, i.e. the little silent place. But who are we to judge what you do in the privacy of your home? So if you ever felt a lack of instrumental accompaniment, or forgot to bring your guitar, [Max Björverud] has just the perfect installation for you. (Video, embedded below.)

Inspired by the way bicycle computers determine your speed, [Max] took a set of toilet paper holders, extended each roll holding part with a 3D-printed attachment housing a magnet, and installed a Hall-effect sensor to determine the rolling activity. The rolls’ sensor data is then collected with an Arduino Mega and passed on to a Raspberry Pi Zero running Pure Data, creating the actual sounds. The sensor setup is briefly shown in another video.

Before you grab your pitchforks, [Max] started this project a little while back already, long before toilet paper became an object of abysmal desire. Being an artist in the field of interactive media, this also isn’t his first project of this kind, and you can find some more of his work on his website. So why of all things did we pick this one? Well, what can we say, we definitely have a weakness for strange and unusual musical instruments. And maybe there’s potential for some collaboration here?
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COBOL Isn’t The Issue: A Misinterpreted Crisis

April 20, 2020 by 142 Comments

Is history doomed to repeat itself? Or rather, is there really any doubt that it isn’t, considering recent events that made the news? I am of course talking about New Jersey’s call for COBOL programmers to fix their ancient unemployment system, collapsing under the application spikes caused by the COVID-19 lockdown. Soon after, other states joined in, and it becomes painfully apparent that we have learned absolutely nothing from Y2K: we still rely on the same old antiques running our infrastructure, and we still think people want to voluntarily write COBOL.

Or maybe they do? Following the calls for aid, things went strangely intense. IBM announced to offer free COBOL trainings and launched a forum where programmers can plug their skills and availability. The Open Mainframe Project’s COBOL programming course suddenly tops the list of trending GitHub projects, and Google Trends shows a massive peak for COBOL as well. COBOL is seemingly on its way to be one of the hottest languages of 2020, and it feels like it’s only a matter of time until we see some MicroCOBOL running on a Teensy.

However, the unemployment systems in question are unfortunately only a tiny selection of systems relying on decades old software, written in a language that went out of fashion a long time ago, which makes it difficult to find programmers in today’s times. Why is that?

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Quarantine Clock Focuses On The Essential

April 12, 2020 by 21 Comments

In these dire times of self quarantining, social distancing, and life as know it coming to a halt, time itself can become rather blurry, and even word clocks may seem unnecessarily precise — especially if you happen to have a more peculiar circadian rhythm. And let’s face it, chances are your usual schedule has become somwehat irrelevant by now, so why bother yourself with dates or an exact time anyway? If you can relate to this, then [mwfisher3] has the perfect clock for you, displaying only the day of the week and a rough estimate of how far that day has progressed.

Using a Raspberry Pi and a spare touch screen, [mwfisher3] had an easy game to begin with, so the clock itself is just Chrome running in Kiosk mode, displaying a local web site with the hours of the day mapped to an array of their textual representation. A few lines of JavaScript are then updating the web site content with the current day and “time”, and a Python script is handling the screen’s back light based on the readings from a Philips Hue motion sensor, using the phue library.

While this is definitely one of the simpler clock projects we’ve seen, this simplicity offers actually a great introduction to some easy JavaScript-based web displays on a Raspberry Pi without much fuzz and distraction. But if that’s not your thing, and you like things more mechanical, we’ve recently covered this day clock that follows the same idea, and then there’s also this light box for an artistic approach of getting a rough estimate of the time.

BCD To I2C: Turning A Nixie Counter Into Whatever You Want It To Be

March 28, 2020 by 3 Comments

Whenever a project calls for displaying numbers, a 7-segment display is the classic and straightforward choice. However, if you’re more into a rustic, retro, almost mystical, and steampunky look and feel, it’s hard to beat the warm, orange glow of a Nixie tube. Once doomed as obsolete technology of yesteryear, they have since reclaimed their significance in the hobbyist space, and have become such a frequent and deliberate design choice, that it’s easy to forget that older devices actually used them out of necessity for lack of alternatives. Exhibit A: the impulse counter [soldeerridder] found in the attic that he turned into a general-purpose, I2C controlled display.

Instead of just salvaging the Nixie tubes, [soldeerridder] kept and re-used the original device, with the goal to embed an Intel Edison module and connect it via I2C. Naturally, as the counter is a standalone device containing mainly just a handful of SN74141 drivers and SN7490 BCD counters, there was no I2C connectivity available out of the box. At the same time, the Edison would anyway replace the 7490s functionality, so the solution is simple yet genius: remove the BCD counter ICs and design a custom PCB containing a PCF8574 GPIO expander as drop-in replacement for them, hence allowing to send arbitrary values to the driver ICs via I2C, while keeping everything else in its original shape.

Containing six Nixie tubes, the obvious choice is of course to use it as a clock, but [soldeerridder] wanted more than that. Okay, it does display the time, along with the date, but also some sensor values and even the likes on his project blog. If you want to experiment with Nixie tubes yourself, but lack a matching device, Arduino has you obviously covered. Although, you might as well go the other direction then.

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Wind Farms In The Night: On-Demand Warning Lights Are Coming

March 24, 2020 by 117 Comments

There appears to be no shortage of reasons to hate on wind farms. That’s especially the case if you live close by one, and as studies have shown, their general acceptance indeed grows with their distance. Whatever your favorite flavor of renewable energy might be, that’s at least something it has in common with nuclear or fossil power plants: not in my back yard. The difference is of course that it requires a lot more wind turbines to achieve the same output, therefore affecting a lot more back yards in total — in constantly increasing numbers globally.

Personally, as someone who encounters them occasionally from the distance, I find wind turbines mostly to be an eyesore, particularly in scenic mountainous landscapes. They can add a futuristic vibe to some otherwise boring flatlands. In other words, I can not judge the claims actual residents have on their impact on humans or the environment. So let’s leave opinions and emotions out of it and look at the facts and tech of one issue in particular: light pollution.

This might not be the first issue that comes to mind when thinking about wind farms. But wind turbines are tall enough to require warning lights for air traffic safety, and can be seen for miles, blinking away in the night sky. From a pure efficiency standpoint, this doesn’t seem reasonable, considering how often an aircraft is actually passing by on average. Most of the time, those lights simply blink for nothing, lighting up the countryside. Can we change this?

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Eavesdropping Assistant Disturbs The Sound Of Silence

March 22, 2020 by 12 Comments

Unless you happen to be from Finland, this is just an all too familiar situation: you’re stuck in an inescapable situation with this one person who is really more of an acquaintance than a friend, and neither of you knows who should say something in hopes of keeping a conversation going. Awkward silence is inevitable, and the longer it lasts, the more excruciating the thought of opening your mouth becomes. Well, consider those days over, thanks to [Jasper Choi] and his friends, who blessed us with the System for Awkward Silence Solution and Interaction Enhancer, or SASSIE.

Built as a laser-cut rotating cylinder, and equipped with a pair of microphones, SASSIE detects and counts the duration of any ongoing silence in the room. Once a pre-defined time limit is reached, it rotates itself to a random direction, symbolically pointing a finger to one of the people present in the room to indicate its their turn to speak now. To break the silence right off the bat, the finger pointing is accompanied by some pre-recorded messages. Unfortunately the audio files exceeded the storage of the Arduino Uno used here, so the responsibilities had to be divided between two Arduinos, arranged with the help of some simple serial communication.

While this is obviously a tongue-in-cheek project, it might just be a welcoming relieve for people with social anxiety, and there is definitely potential to take the idea further. Maybe with some inspiration from this happy robot fellow, a future version might ease the conversation even further by suggesting a topic along the way.

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Sweet Streams Are Made Of These: Creating Music On The Command Line

March 19, 2020 by 3 Comments

There are countless ways to create music. In the simplest form, it won’t even require any equipment, as evidenced by beatboxing or a capella. If we move to the computer, it’s pretty much the same situation: audio programming languages have been around for as long as general-purpose high-level languages, and sound synthesis software along with them. And just as with physical equipment, none of that is particularly necessary thanks to sed. Yes, the sed, the good old stream editor, as [laserbat] shows in her music generating script.

Providing both a minified and fully commented version of Bach’s Prelude 1 in C major as example, [laserbat] uses a string representation of the sheet music as the script’s starting point, along with a look-up table of each transformed note’s wavelength. From here, she generates fixed length PCM square wave signals of each of the notes, to be piped as-is to the sound card via ALSA’s aplay or SoX’s play. To keep things simple enough, she stays within the region of printable characters here, using space and tilde as low and high values respectively, providing highest possible volume at the same time this way.

The concept itself is of course nothing new, it’s how .au and .wav files work, as well as these little C lines. And while the fixed note duration takes away some of the smoothness in [laserbat]’s version, adding variable duration might just be a hint too much for a sed implementation, although we’ve certainly seen some more complex scripts in the past.

[via r/programming]