Year: 2017

Stealing Joules From An Aluminium-Air Battery

July 28, 2017 by 36 Comments

While batteries are cheap and readily obtainable today, sometimes it’s still fun to mess around with their less-common manifestations. Experimenting with a few configurations, Hackaday.io user [will.stevens] has assembled an aluminium-air battery and combined it with a joule thief to light an LED.

To build the air battery, soak an activated charcoal puck — from a water filter, for example — in salt-saturated water while you cut the base off an aluminium can. A circle of tissue paper — also saturated with the salt water — is pressed between the bare charcoal disk and the can, taking care not to rip the paper, and topped off with a penny and a bit of wire. Once clamped together, the reaction is able to power an LED via a simple joule thief.

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Where A Wood Shop Goes, A Hackerspace Follows

July 28, 2017 by 18 Comments

The 2×4 Contest at my local hackerspace captured my interest. The challenge was to build something cool out of a single eight-foot 2×4 with the winner getting free wood storage in the space. I had half an idea for a project, but I ran out of time and never even started it. My idea was to cut the board into half-thickness strips and glue them edge-to-edge with some biscuits holding them together — to basically make wider, thinner boards to do… something cool with it.

One of the entries is pictured above. [Jon Alt] designed this clock and phone charger that includes a capacitive charger for his smart watch. He makes use of the 2×4’s grain to make a gorgeous enclosure, carving away the rear of the front panel so only a credit-card’s thickness of wood remained, allowing the 7-segments to shine through. The other entries were great as well and I especially liked the 2×4 guitar.

Mostly what interested me about the contest was what it showed about the wood shop: thanks to the volunteers and board, that is a wood shop doing well. Stuff is going on! A sad wood shop doesn’t hold contests. By extension, when the shop is doing well, that means the hackerspace is also doing well.

A wood shop is one of those areas of a hackerspace that is tool-driven. It’s not just a gathering place for like-minded folks; people go to use a specific tool or tools they can’t afford, and let’s face it, there’s always tools to buy that costs a bunch of money.

I’ve seen this particular shop begin as an empty concrete room with a cheap drill press and someone’s old bandsaw. Pretty soon worktables, shelving, and storage were built. More tools arrived, some donated, some loaned, some purchased with dues. So how can other spaces replicate this wood shop success story?

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OpenEMS Makes Electromagnetic Field Solving… Merely Difficult

July 28, 2017 by 21 Comments

To ordinary people electronics is electronics. However, we know that the guy you want wiring your industrial furnace isn’t the guy you want designing a CPU. Neither of those guys are likely to be the ones you want building an instrumentation amplifier. However, one of the darkest arts of the electronic sects is dealing with electromagnetic fields. Not only is it a rare specialty, but it requires a lot of high-powered math. Enter OpenEMS, a free and open electromagnetic field solver.

We would like to tell you that OpenEMS makes doing things like antenna analysis easy. But that’s like saying Microsoft Word makes it easy to write a novel. In one sense, yes, but you still need to know what you are doing. In fairness, though, the project does provide a good set of tutorials, ranging from a simple wave guide to a sophisticated phased array of patch antennas. Our advice? Start with the waveguide and work your way up from there.

The software uses Octave or MATLAB for scripting, plotting, and support. You can download it for Windows or Linux.

If you want to start with something more intuitive for electromagnetic field visualization, this might help. If you prefer your models more concrete and less abstract, perhaps you should work at Lincoln Lab.

North Carolina Hackerspace Destroyed By Fire, Members Vow To Rebuild

July 28, 2017 by 66 Comments

There’s something about old industrial buildings that just seems to attract hackerspaces. It could be the open floor plans typical in buildings that used to house big manufacturing operations, or it could be a desire to reinvigorate places where machines once hummed and skilled hands plied their trades. Whatever the attraction, the relationship is not without risk; old buildings with wood floors and frames can be tinderboxes, and tragedy can strike at any moment.

Such a fate befell The Foothills Community Workshop in Granite Falls, North Carolina, this past Friday. Details are still sketchy as the remnants of the 75,000-square foot former Shuford Mills textile factory are still smoldering, and the Fire Marshal’s investigation is not yet complete. Thankfully, no lives were lost, and injuries were limited to heat exhaustion of several of the firefighters from 16 counties who battled the blaze in the hot and humid North Carolina Piedmont.

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Four Chords Should Be Enough For Anyone

July 28, 2017 by 32 Comments

You might be surprised at how many pop songs are exactly the same. Cat Scratch Fever is the exact same song as Smoke on the Water. Even one of Yeezy’s songs is strikingly similar to a weird 90s French electronic group. Musically, though, there are an incredible number of songs that follow a I-V-vi-IV progression. Let it Be is one of them, as is Beast of Burden. Lady Gaga’s Poker Face is another. Now, finally, we have automated most of the pop songs you know and love. [Sven] has created a small MIDI device that only plays a I-V-vi-IV progression, and it’s everything you could ever imagine.

The idea for this build comes from an Axis of Awesome routine demonstrating the fact that hundreds of pop songs follow the same progression. After the idea, the implementation, like the music all those millennials are listening to, is simple.

The 4chord MIDI is a small board with an old Nokia display, buttons, a single USB port, and an ATMega328 microcontroller. Using MIDI over USB, it plays the I-V-vi-IV progression in any key. It plays in chord mode, arpeggiated mode, or mixed mode at any sensible tempo.

You can check out a video of the 4chord playing several hundred songs simultaneously below.

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Give Your Bench Power Supply A Helping Hand

July 28, 2017 by 12 Comments

[Sverd Industries] have created a pretty cool bench power supply integrating soldering helping hands into the build. This helps free up some much-needed bench space along with adding that wow factor and having something that looks unique.

The build is made from a custom 3D printed enclosure (Thingiverse files here), however if you have no access to a 3D printer  you could always just re-purpose or roll your own instrument enclosure. Once the enclosure is taken care of, they go on to install the electronics. These are pretty basic, using a laptop PSU with its output attached to the input of a boost/buck module. They did have to change the potentiometers from those small PCB mounted pots to full size ones of the same value though. From there they attach 4 mm banana sockets to the output along with a cheap voltmeter/ammeter LCD module. Another buck converter is attached to the laptop PSU’s output to provide 5 V for a USB socket, along with a power switch for the whole system.

Where this project really shines is the integrated helping hands. These are made from CNC cooling tubes with alligator clips super glued to the end, then heat shrink tubing is placed over the jaws to stop any accidental short circuiting while using them.

This isn’t a life changing hack but it is quite a clever idea if space is a hot commodity where you do your tinkering, plus a DIY bench power supply is almost a rite of passage for the budding hacker.

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Edit Hex In The Browser

July 27, 2017 by 28 Comments

If you can’t stand the thought of using an application in your browser, you might as well jump ahead to the comments and start flaming.

Still with us? Imagine this scenario. You are at the office, at a client’s site, at a school, or visiting your mom. Suddenly, for some strange reason, you need to edit a hex file. We don’t know why, but if you are reading Hackaday, it isn’t that big of a stretch to imagine it. What do you do? Download and install a hex editor? Maybe you can’t. Or, if it is mom’s computer, maybe you just don’t want to. Your next option is to navigate to HexEd.it.

The application, by [Jens Duttke], uses HTML5 and JavaScript and is actually a nicely capable editor. It shows the data in hex and ASCII as you’d expect. It also shows the current cursor location in a number of formats like 8-bit integer, 32-bit integer, date and time, and more. It even shows all the representations as big endian and little endian.

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