PiSound, The Audio Card For The Raspberry Pi

Kids today are being loud with their ‘drum machines’ and ‘EDM’. Throw some Raspberry Pis at them, and there’s a need for a low-latency sound card with MIDI and all the other accouterments of the modern, Skrillex-haired rocker. That’s where PiSound comes in.

Of course, the Pi already comes with audio out, but that’s not enough if you want to do some real audio processing. You need audio in as well, and while you’re messing around with that, adding some high-quality opamps, ADCs, DACs, and some MIDI would be a good idea. This is what the PiSound is all about.

[Pranciskus], the guy who has been working on the PiSound for a while now, developed this multitool for audio on a tiny Linux system. One of the killer features on the PiSound is ‘The Button’, a simple tact switch that runs a script if the button is pressed, another script if the button is held down, and two more if the button is pressed two or three times. This is actually a pretty nifty UI, and we wouldn’t mind seeing this on a few more Pi accessories.

If you’d like to see some example projects using the PiSound, there example MIDI controllers, networked audio players, and some goofing around with LV2 plugins over here.

A Wordsearch Twist on the Word Clock

We love seeing new takes on existing ideas, and [Danny] certainly took the word clock concept in an unusual direction with his Wordsearch Clock. Instead of lighting up words to spell out the time, [Danny] decided to embrace the fact that the apparent jumble of letters on the clock face resembles a word search puzzle.

In a word search puzzle, words can be found spelled forward or backward with letters lined up horizontally, diagonally, or vertically. All that matters is that the correct letters are in a line and sequentially adjacent to one another. [Danny]’s clock lights up the correct letters and words one after the other, just as if it were solving a word search puzzle for words that just happen to tell the correct time. You can see it in action in the video, embedded below.

[Danny] went the extra mile in the planning phase. After using a word search puzzle generator tool to assist in designing the layout, he wrote a Processing sketch to simulate the clock’s operation. Visually simulating the clock allowed him to make tweaks to the layout, identify edge cases to address, and gain insight into the whole process. If you’re interested in making your own, there is a GitHub repository for the project.

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Toy Car Pumps the Wheels with Balloon Power

We’ve had our eye on [Greg Zumwalt]. He’s been working on some very clever 3D-printed mechanisms and his latest prototype is an air engine for a toy car. You can supply the air for the single cylinder with a compressor, or by blowing into it, but attaching an inflated balloon makes the system self-contained.

Last week we saw the prototype of the engine by itself, and wondered if this had enough power to drive a little train engine. We were almost right as here it is powering the front wheels of a little car.

This isn’t [Greg’s] first rodeo. He’s been working on self-contained locomotion for a while now. Shown here is his spring-driven car which you pull backwards to load the spring. It’s a common feature in toys, and very neat to see with the included 3D-printed spring hidden inside of the widest gear.

That print looks spectacular, but the balloon-powered prototype tickles our fancy quite a bit more. Make sure you have your sound on when you watch the video after the break. It’s the chuga-chuga that puts this one over the top. [Greg] hasn’t yet posted files so you can print your own (it’s still a prototype) but browse the rest of his designs as you wait — they’re numerous and will bring an even bigger smile to your face. Remember that domino-laying LEGO bot [Matthias Wandel] built a few years back? [Greg] has a printable model for it!

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Old Batteries Yield Thermite and Manganese

Some people collect stamps, some collect coins, some even collect barbed wire. But the aptly named [Plutonium Bunny] is an element collector, as in one who seeks a sample of as many elements on the periodic table as possible. Whatever, we don’t judge – after all, there are more than a few Hackaday readers who collect lots of silicon, right?

So what’s a collector to do when he gets to the 25th place on the periodic table? Easy – harvest manganese from alkaline batteries with a thermite reaction. There’s a surprising amount of manganese in depleted alkaline batteries, which of course are easy to come by in bulk. The chemistry of [Plutonium Bunny]’s process is pretty straightforward and easy to reproduce with common ingredients, but you’ll want to be careful with a few steps – chlorine gas is not something to trifle with. The basic idea is to solubilize and purify the manganese dioxide from the other materials in the battery cathodes, recrystallize it, and mix it with aluminum powder. The aluminum acts as the fuel, the manganese dioxide is the oxidizer, and once the satisfyingly exothermic reaction shown in the video below is over, the collector-grade elemental manganese can be chipped away from the aluminum oxide slag.

So once you’ve got a few manganese nuggets, what can you do with them? Not much really – it turns out the oxides recovered from the battery are far more useful for things like supercapacitors. But it’s still a neat trick.

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NASA’s 2017-2018 Software Catalog is Out

Need some help sizing your beyond-low-Earth-orbit vehicle? Request NASA’s BLAST software. Need to forecast the weather on Venus? That would be Venus-GRAM (global reference atmospheric model). Or maybe you just want to play around with the NASA Tensegrity Robotics Toolkit. (We do!) Then it’s a good thing that part of NASA’s public mandate is making their software available. And the 2017-2018 Software Catalog (PDF) has just been released.

Unfortunately, not everything that NASA does is open source, and a substantial fraction of the software suites are only available for code “to be used on behalf of the U.S. Government”. But still, it’s very cool that NASA is opening up as much of their libraries as they are. Where else are you going to get access to orbital debris engineering models or cutting-edge fluid dynamics modelers and solvers, for free?

We already mentioned this in the Links column, but we think it’s worth repeating because we could use your help. The catalog is 154 pages long, and we haven’t quite finished leaf through every page. If you see anything awesome inside, let us know in the comments. Do any of you already use NASA’s open-source software?

Retrotechtacular: How Old is the Remote?

A few weeks ago we covered a (probably) bogus post about controlling a TV with the IR from a flame. That got us thinking about what the real origin of the remote control was. We knew a story about the 38 kHz frequency commonly used to modulate the IR. We’ve heard that it was from sonar crystals used in earlier sonic versions of remotes. Was that true? Or just an urban myth? We set out to find out.

Surprise! Remotes are Old!

If you are a younger reader, you might assume TVs have always had remotes. But for many of us, remotes seem like a new invention. If you grew up in the middle part of the last century it is a good bet you were your dad’s idea of a remote control: “Get up and turn the channel!” Turns out remotes have been around for a long time, though. They just weren’t common for a long time.

If you really want to stretch back, [Oliver Lodge] used a radio to move a beam of light in 1894. In 1896, [Marconi] and some others made a bell ring by remote control. [Tesla] famously showed a radio-controlled boat in 1898. But none of these were really remote controls like we think of for a television.

mysteryOf course, TV wouldn’t be around for a while, but by the 1930’s many radio manufacturers had wired remotes for radios. People didn’t like the wires, so Philco introduced the Mystery Control in 1939. This used digital pulse coding and a radio transmitter. That’s a fancy way of saying it had a dial like an old telephone. As far as we can tell, this was the first wireless remote for a piece of consumer equipment.

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Super Computing with Mini ITX Cluster

[Colin Alston] was able to snag a handful of Mini ITX motherboards for cheap and built a mini super computer he calls TinyJaguar. Named partly after the AMD Sempron 2650 APU, the TinyJaguar boasts four, yes that’s four MSI AM1I Mini-ITX motherboards, each with 4GB of DDR memory.

A Raspberry Pi with custom software manages the cluster, and along with some TTL and relays, controls the power to the four nodes. The mini super computer resides in a custom acrylic case held together by an array of 3D printed parts and fasteners.There’s even a rack-like faceplate near the bottom to host the RPi, an Ethernet switch, an array of status LEDs, and the two buttons.

With 16 total cores of computing power (including GPU), the TinyJaguar is quite capable of doing some pretty cool stuff such as running Jupyter notebook with IPyParallel. [Colin] ran into some issues getting the GPU to behave with PyOpenCL. It took a bit of pain and time, but in the end he was able to get the GPUs up, and wrote a small message passing program to show two of the cores were up and working together.

Be sure to check out [Colin’s] super computer project page, specifically the ten project logs that walk through everything that went into this build. He also posted his code if you want to take a look under the hood.