Fire Extinguisher Ball Mill Destined to Grind Kitty Litter

Nothing says hack like a tool quickly assembled from a few scrap-heap parts. For [Turbo Conquering Mega Eagle], his junkyard finds were a fire extinguisher, an old office fan, and a few scraps of plywood; the result was a quick and easy ball mill.

There’s very little mention of what said ball mill will be for — [TCME] said something about milling bentonite clay, AKA kitty litter — but that’s hardly the point. Having previously fabricated a much smaller version of this ball mill that could chuck up in his lathe, he scaled this one up considerably. The spent fire extinguisher was relieved of the valve and some external bits to create the mill’s drum. Plywood was used for a quick frame to support rollers and to turn a couple of pulleys for the running gear. The fan motor proved barely capable of performing, though, even with the mechanical advantage of the pulleys and an improvised drive belt. The motor just didn’t have the oomph to turn the drum when loaded with ceramic balls, but a quick adjustment to the drive train did the trick. The video below shows the whole build process, which couldn’t have taken much more than a couple of hours.

It looks like a sand casting project may be on deck for [TCME]’s milled bentonite, so we’ll look forward to that. Perhaps his other recent fire extinguisher build will make an appearance in that video too.

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What is Twitter Without the Numbers?

How many people liked your last tweet? Oh yeah? Didja get any retweets? Was it enough to satisfy your need for acceptance, or were you disappointed by the Twitterverse’s reaction?

If you couldn’t see the number of likes, retweets, or followers you had, would you still even use Twitter?

[Ben Grosser] wants to know. He’s trying to see if people will look their relationship with social media squarely in the eye and think honestly about how it affects them. After all, social media itself isn’t the bad guy here—we are all responsible for our own actions and reactions. He’s created a browser extension that demetricates Twitter by removing any bluebird-generated quantifier on the page. It works for tweets, retweets, and the number of tweets playing the trending tag game. Numbers inside of tweets and on user profiles aren’t hidden, however, so you’ll still be able to see, for example, tweets containing Prince lyrics.

The Twitter Demetricator is available as a Chrome extension, and as a userscript for Tampermonkey for the other browsers people actually use (read: no IE support). Here’s what we want to know: Can he gamify it? Can he make a game out of weaning ourselves off of these meaningless metrics and inflated sense of self and FOMO and whatever marketing guff they come up with next to describe the modern human condition? We’re getting low on dopamine over here.

This isn’t [Ben]’s first foray into the social aspects of social media. We covered his Facebook demetricator way back in ’12.

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Tiny Function Generator on the ATtiny85, Complete with OLED

It’s easy to have a soft spot for “mini” yet perfectly functional versions of electronic workbench tools, like [David Johnson-Davies]’s Tiny Function Generator which uses an ATtiny85 to generate different waveforms at up to 5 kHz. It’s complete with a small OLED display to show the waveform and frequency selected. One of the reasons projects like this are great is not only because they tend to show off some software, but because they are great examples of the kind of fantastic possibilities that are open to anyone who wants to develop an idea. For example, it wasn’t all that long ago that OLEDs were exotic beasts. Today, they’re available off the shelf with simple interfaces and sample code.

The Tiny Function Generator uses a method called DDS (Direct Digital Synthesis) on an ATtiny85 microcontroller, which [David] wrote up in an earlier post of his about waveform generation on an ATtiny85. With a few extra components like a rotary encoder and OLED display, the Tiny Function Generator fits on a small breadboard. He goes into detail regarding the waveform generation as well as making big text on the small OLED and reading the rotary encoder reliably. His schematic and source code are both available from his site.

Small but functional microcontroller-based electronic equipment are nifty projects, and other examples include the xprotolab and the AVR-based Transistor Tester (which as a project has evolved into a general purpose part identifier.)

Solar Power In A Can!

When spending time camping, people often bring lanterns, flashlights, and the like — you might even bring along a solar charger. Instructables user [bennelson] is combining all your electrical powered needs by cramming solar power into a can.

Already designed to resist the elements, [bennelson] is using a 50cal. ammo can for a portable enclosure. Inside, he’s siliconed a 15AH, 12V lead-acid battery in the centre to maintain balance and to leave room for the wiring and storage. One cardboard mockup later, he laser-cut the top panel from 1/8″ plywood and secured a 20A solar charge controller, a four-in-one socket panel, and two banana plugs on its top face.

[bennelson] is using 12 AWG wire to match the 20A rating of the solar charge controller — including a fuse for safety — and lever lock-nut connectors to resolve some wiring complications. Industrial velcro keeps the top panel in place and easily removed should the need arise. When he’s out camping, he uses an 18V, 1A solar panel to charge, but can still use a DC power adapter to charge from the grid. Check out the full build video after the break!

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Microchip Acquires Microsemi For $8.35B

Microchip has acquired Microsemi for $8.35 Billion dollars. Rumors of this acquisition were floating around earlier this week, but now the deal is done.

This acquisition is the latest in a years-long process of consolidation in the silicon industry. Previously, Broadcom attempted a hostile takeover of Qualcomm for One… Hundred… Billion dollarsLattice would have been bought if the deal wasn’t shut down for national security concerns. Of course, Microchip bought Atmel in a deal likened to the fall of Constantinople, NXP and Freescale merged, Intel bought Altera, Linear and Analog are one, and On Semiconductor acquired Fairchild.

With the acquisition of Microsemi, Microchip will be looking to add a few interesting components and capabilities to their portfolio. In contrast to Microchip’s portfolio, you won’t find many Microsemi parts on a hacker’s workbench; they’re dealing with stuff like optical networking and avionics. Closer to home, they have a large line of FPGAs and some nice frequency synthesizers.

Of course, there are slightly cooler components in Microsemi’s portfolio. If you’ve ever wanted a rad-tolerant telemetry controller for reaction wheels and thruster assemblies, they’ve got your back. Just connect that to Microchip’s rad-hard Arduino and you have a complete satellite built from Microchip parts.

Unionize Your Variables – An Introduction to Advanced Data Types in C

Programming C without variables is like, well, programming C without variables. They are so essential to the language that it doesn’t even require an analogy here. We can declare and use them as wildly as we please, but it often makes sense to have a little bit more structure, and combine data that belongs together in a common collection. Arrays are a good start to bundle data of the same type, especially when there is no specific meaning of the array’s index other than the value’s position, but as soon as you want a more meaningful association of each value, arrays will become limiting. And they’re useless if you want to combine different data types together. Luckily, C provides us with proper alternatives out of the box.

This write-up will introduce structures and unions in C, how to declare and use them, and how unions can be (ab)used as an alternative approach for pointer and bitwise operations.

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Basic Sequencer for your Synth Rack

Sequencers are useful for bringing regular structure to your music, particularly if you enjoy noodling around with rackmount synthesizers. [little-scale] is here to share an ADC Binary Gate sequencer for your setup.

In a quest for ever greater minimalism, the build relies on a barebones ATMega328p without an external oscillator. Instead, the chip’s internal RC oscillator is used instead. It’s possible to still use this with the Arduino IDE, as [little-scale] shares here.

The music production begins with a clock input signal, which is patched in from elsewhere in the rack synth. The sequencing is controlled with potentiometers. There are four potentiometers, and four corresponding output channels.  The pots are all read with the onboard analog to digital converters, and the position transformed into an 8-bit value, from 0 to 255. Our best understanding is that the 8-bit number is then used as the sequence to follow. For example, if the potentiometer is set to 255, which is 11111111 in binary, the sequencer will trigger on every beat. If instead the potentiometer was turned to around 2/3rds of the maximum, and the ADC reads a value of 170, in binary this is 10101010 which would trigger on every second beat.

It’s an interesting way to sequence several channels with the bare minimum of input devices. While it may not be the most intuitive system, it really suits the knob-and-dial noodling so relished by rackmount fanatics. Be sure to check out the video below for [little-scale]’s rackmount sounds and impressively pretty videography.  Never before did breadboards look so good.

New to rack mount synths? Check this one out.