What Makes A Hacker

October 23, 2017 by 114 Comments

I think I can sum up the difference between those of us who regularly visit Hackaday and the world of non-hackers. As a case study, here is a story about how necessity is the mother of invention and the people who invent.

Hackaday has overlap with sites like Pinterest and Instructables but there is one vital difference, we choose to create something new and beautiful with the materials at hand. Often these tools and techniques are very simple. We look to make things elegant by reducing the unnecessary clutter, not adding glitter. If something could be built with a 555 timer we will let you know. If there is a better choice for a processor, we will tell you.

My first real work commute was a forty-minute eastward drive every morning and a forty-minute westward drive every evening. This route pointed my car directly into the sun twice a day. Staring into a miasma of incandescent plasma for an hour and a half a day isn’t fun, and probably isn’t safe, but we can fix that.

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Solving Mazes With Graphics Cards

October 23, 2017 by 16 Comments

What if we told you that you are likely to have more computers than you think? And we are not talking about things that are computers while not looking like one, like most modern cars or certain lightbulbs. We are talking about the powerful machines hiding in your desktop computer called ‘graphics card’. In the ordinary gaming rig graphics cards that are much more powerful than the machine they’re built into are a common occurrence. In his tutorial [Viktor Chlumský] demonstrates how to harness your GPU’s power to solve a maze.

Software that runs on a GPU is called a shader. In this example a shader is shown that finds the way through a maze. We also get to catch a glimpse at the limitations that make this field of software special: [Viktor]’s solution has to work with only four variables, because all information is stored in the red, green, blue and alpha channels of an image. The alpha channel represents the boundaries of the maze. Red and green channels are used to broadcast waves from the beginning and end points of the maze. Where these two waves meet is the shortest solution, a value which is captured through the blue channel.

Despite having tons of cores and large memory, programming shaders feels a lot like working on microcontrollers. See for yourself in the maze solving walk through below.

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MakerBot Really Wants You To Like Them Again

October 23, 2017 by 76 Comments

For the last couple years, a MakerBot press release has generally signaled that more pink slips were going to be heading out to the already shell-shocked employees at their NYC factory. But just last week something that could almost pass as good news came out of the once mighty 3D printer manufacturer, the unveiling of “MakerBot Labs”. A number of mainstream tech sites heralded this as MakerBot’s first steps back into the open source community that launched it nearly a decade ago; signs of a newer and more thoughtful MakerBot.

Reading the announcement for “MakerBot Labs”, you can almost believe it. All the buzz words are there, at least. In fact, if this announcement came from anyone else, in any other field, I’d probably be on board. Sharing knowledge and listening to the community is essential if you want to connect with hackers and makers. But this is MakerBot, and they’ve dug themselves into a very deep hole over the years.

The spectacular fall from grace that MakerBot has experienced, from industry leader to afterthought, makes this hat-in-hand peace offering hard to take seriously. It reads like a company making a last ditch effort to win back the users they were so sure they didn’t need just a few years ago. There is now a whole new generation of 3D printer owners who likely have never even seen a MakerBot printer, and it’s hard to imagine there’s still enough innovation and life in the company to turn that around before they completely fade into obscurity.

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The Grafofon: An Optomechanical Sequencer

October 23, 2017 by 4 Comments
There are quick hacks, there are weekend projects and then there are years long journeys towards completion.  [Boris Vitazek]’s grafofon falls into the latter category. His creation can best be described as electromechanical sequencer synthesizer with a multiplayer mode.
The storage medium and interface for this sequencer is a thirteen-meter loop of paper that is mounted like a conveyor belt. Music is composed by drawing on the paper or placing objects on it. This is usually done by the audience and the fact that the marker isn’t erased make the result collaborative and incremental.
 These ‘scores’ are read by a camera and interpreted by software.This is a very vague description of this device, for a reason: the build went on over six years and both hard- and software went through several revisions in that time. It started as a trigger for MIDI notes and evolved from there.
In his write up [Boris] explains the technical aspects of each iteration. He also tells the stories of the people he met while working on the grafofon and how they influenced the build. If this look into the art world reminds you of your local hackerspace, it is because these worlds aren’t that far apart.

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Lithium Ion Versus LiPoly In An Aeronautical Context

October 23, 2017 by 32 Comments

When it comes to lithium batteries, you basically have two types. LiPoly batteries usually come in pouches wrapped in heat shrink, whereas lithium ion cells are best represented by the ubiquitous cylindrical 18650 cells. Are there exceptions? Yes. Is that nomenclature technically correct? No, LiPoly cells are technically, ‘lithium ion polymer cells’, but we’ll just ignore the ‘ion’ in that name for now.

Lithium ion cells are found in millions of ground-based modes of transportation, and LiPoly cells are the standard for drones and RC aircraft. [Tom Stanton] wondered why that was, so he decided to test the energy density per mass of these battery chemistries, and what he found was very interesting.

The goal of [Tom]’s experiment was to test LiPoly against lithium ion batteries in the context of a remote-controlled aircraft. Since weight is what determines flight time, cutting even a few grams from an airframe can vastly extend the capabilities of an aircraft. The test articles for this experiment come in the form of a standard 1800 mAh LiPoly battery and four 18650 cells wired together as a 3000 mAh battery. Here’s where things get interesting: the LiPoly battery weighs 216 grams for an energy density of 0.14 Watt-hours per gram. The lithium ion battery weighs 202 grams for an energy density of 0.25 Watt-hours per gram. If you just look at the math, all drones are doing it wrong. 18650 cells appear to have a much higher energy density per mass than the usual LiPoly cells. How does that hold up in a real-world test, though?

Using his neat plane with 3D printed wing ribs as the testbed, [Tom] plugged in the batteries and flew around a field for the better part of an afternoon. The LiPo flew for 41.5 minutes, whereas the much more energy dense lithium ion battery flew for 36.5 minutes. What’s going on here?

While the lithium ion battery has a much higher capacity, the problem here is the internal resistance of each battery chemistry. The end voltage for the LiPo was a bit lower than the lithium ion battery, suggesting the 18650 cells can be run down a bit further than [Tom]’s test protocol allowed. After recharging each of these batteries and doing a bit of math, [Tom] found the lithium ion batteries can fly for about twice as long as their LiPo counterparts. That means an incredibly long test of flying a plane in a circle over a field; not fun, but we are looking forward to other people replicating this experiment.

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Dual Direction Gaming/Dining Room Beam Lights

October 22, 2017 by 21 Comments

Sometimes, you just can’t find something you want, and that’s when you break out the tools and get dirty with a bit of DIY. Reddit user [JaredBanyard] wanted a nice beam light for the dining room/gaming room. He ended up building one that shone both downward, on the table, and upward, adding some light to the room.

Warm white LED strip lighting was chosen, and two aluminum channels were glued together to hold them. After wiring the four LED strips together a diffuser was placed over them and then they were wired up and turned on to check the amount of light. With two strips per channel, even with the diffuser, there was plenty.

Each pair of channels were set into the main housing, which is made from Sirari hardwood. Two long outside side pieces make for a great looking final product, and the end pieces are sandwiched between the two outside pieces. After a bit of sanding and an application of matte polyacrylic, transformers were screwed inside and then the channels were placed on top. The circuitry was wired to a Z-Wave dimmer to control the lights remotely.

[JaredBanyard]’s put together a bill of materials and there are plenty of pictures. It’s a great, unique, light for the room, which includes a Duchess gaming table from boardgametables.com. For more lighting articles, check out this 2017 Hackaday Prize entry article on modular rail lighting, or this article about adding intelligence to your lighting solution.

[via Reddit]

Using An Arduino To Re-Create A Computer’s Keyboard Decoder

October 22, 2017 by 19 Comments

[Max Breedon] found an old Apple IIe clone twenty years ago. He recently dug this Epson AP-200 out of the salvage heap and quickly discovered that the keyboard decoder chip was fried. The old chip was way too obscure to source a replacement — and soon this post will be the top Google result for the string, ‘C35224E’ — so he busted out his trusty UNO and created a replacement keyboard decoder.

Unlike the Apple II, where all the keyboard decoding happens on the keyboard, this clone used a dedicated chip on the main board. Although it’s a rare part that’s virtually ungoogleable, this chip’s architecture and pinout can be figured out by testing out every trace for continuity. After locating what looked like four data pins, he had the Arduino send signals onto the clone to see what characters popped up. That didn’t work, but it led him to idea that two of the wires were clock and data, and after a bit of experimenting figured out that the third pin was a latch enable of some sort that sent the character.

So, [Max] created an Arduino rig to do the same thing. The Arduino uses a shift register to interact with the keyboard’s 8×10 matrix, and the sketch translates any serial data it receives into the keypresses the clone is expecting. After prototyping with the UNO, [Max] hardwired an Arduino Nano (as well as the shift register) into a daughter board with pins extending into the old chip’s sockets. A permanent solution!

In addition to a weird keyboard controller that has been lost to the sands of time, this Apple IIe clone features a few more parts that are downright weird. There are two chips that are found in a few other Apple clones labeled STK 65301 and STK 65371, used as ASICs, MMUs, or a 20-IC expression of Wozzian brilliance condensed into custom silicon. There’s another weird chip in this clone, a 27c32 ROM loaded up with repetitive bits. There is no obvious 6502 code or strings in this ROM, so if anyone has an idea what this chip does, send [Max] a note.