Beverly-Crusher, The Greatest Name For An Audio Effect

October 10, 2014 by 44 Comments

Image is © aliceazzo [http://aliceazzo.deviantart.com/].
Image © aliceazzo [http://aliceazzo.deviantart.com/].
When it comes to audio effects, you have your delay, reverb, chorus, phasing, and the rest that were derived from strictly analog processes. Compared to the traditional way of doing things, digital audio is relatively new, and there is still untapped potential for new processes and effects. One of those is the bit crusher, an effect that turns 8- or 16-bit audio into mush. [Electronoob] wanted to experiment with bitcrushing, and couldn’t find what he wanted. Undeterred, he built his own.

There are two major effects that are purely in the digital domain. The first is the sample rate reducer. This has a few interesting applications. Because [Shannon] and [Nyquist] say we can only reproduce audio signals less than half of the sample rate; if you run some audio through a sample rate reducer set to 1kHz, it’ll sound like crap, but you’ll also only get bass.

The bitcrusher is a little different. Instead of recording samples of 256 values for 8-bit audio or ~65000 values for 16-bit audio, a one-bit bitcrusher only records one value – on or off. Play it through a speaker at a decent sample rate, and you can still hear it. It sounds like a robotic nightmare, but it’s still there.

[Electronoob] created his bitcrusher purely in software, sending the resulting bitcrushed and much smaller file to an Arduino for playback. Interestingly, he’s also included the ability to downsample audio, giving is project both pure digital effects for the price of one. 1-bit audio is a bit rough on the ears, but 2, 3, and 4-bit audio starts to sound pretty cool, and something that would feel at home in some genres of music.

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A PC Engine To TurboGrafx-16 Converter

October 10, 2014 by 23 Comments

The PC Engine was pretty popular in Japan, but only the coolest kids in America had the US edition, the TurboGrafx16. These two systems weren’t exactly the same; the TurboGrafx-16’s data bus was flipped so the games were made to be incompatible, and the US games have a region lockout. [Kaz] looked at the existing hacks for running Japanese games on US systems, and every single one of them required modding a console. Thinking he could do better, he came up with the PC-Henshin, an adapter and CPLD that allows Japanese game to run on US consoles.

To take care of the mixed up lines on the PC card connector between the US and Japanese variants, a few adapter cards are available. That’s great, but they only solve one part of the compatibility problem. The region lockout routine found on nearly every American title mean PC Engine consoles can’t run TurboGrafx-16 games. [Kaz] used a small, cheap CPLD to read the data bus, patch everything as it is read out, and turns a Japanese console into something that can play American games.

Video below.

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The Cassette MP3 Player

October 9, 2014 by 34 Comments

1994 was twenty years ago. There are people eligible to vote who vaguely remember only one Bush presidency. You can have a conversation with someone born after the millennium, and they think a 3.5 inch disk is called a save icon. Starting to feel old? Don’t worry, all the trinkets of your youth have now become shells for MP3 players, the cassette tape included.

[Britt] is aware you can pick up one of these cassette tape MP3 players through the usual channels, but she wanted her build to be a little different. She’s using ar real, vintage cassette tape for starters, and from the outside, looks pretty much like any other cassette tape: there’s a thin strip of tape at the bottom, and the clear plastic window shows the tape is at the beginning of side A.

Outside appearances are just that; inside, there is a small, repurposed MP3 player, with tact switches wired up to the old buttons, actuated by moving the spools back and forth. Yes, you actually play, pause, rewind and fast forward by sticking a pencil in the spool and moving it back and forth. Amazing.

It’s a great build, and considering both cassette tapes and cheap MP3 players can be found in the trash these days, it’s something that should be hard to replicate.

Toddler Jukebox Requires No Quarters Or Button Mashing

October 9, 2014 by 18 Comments

Ahh, toddlers. They’re as ham-fisted as they are curious. It’s difficult to have to say no when they want to touch and engage with the things that we love and want them to play with. [Shawn] feels this way about his son’s interest in the family Sonos system and engineered an elegant solution he calls Song Blocks.

The Sonos sits on a dresser that hides a RasPi B+. Using bare walnut blocks numbered 1-12, his son can use the Sonos without actually touching it. Each block has a magnet and an NFC tag. When his son sticks a block on the face of the right drawer containing embedded magnets and an NFC controller board, the B+ reads the tag and plays the song. It also tweets the song selection and artist.

The blocks themselves are quite beautiful. [Shawn] numbered them with what look like Courier New stamps and then burned the numbers in with a soldering iron. His Python script is on the git, and he has links to the libraries used on his build page. The Song Blocks demo video is waiting for you after the jump.

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The Triple Delta Robot Arm (and Leg)

October 9, 2014 by 17 Comments

delta By now you’d think we’ve seen just about every means of robotic actuator possible. We have Cartesian bots, Stewart platforms, SCARA bots, Delta bots, and even some exceedingly bizarre linkages from [Nicholas Seward]. We’re not done with odd robotic arms, it seems, and now we have Delta-ish robots that can move outside their minimum enclosed volume. They’re fresh from the workshop of [Aad van der Geest], and he’s calling them double and triple Deltas.

Previous Delta robots have used three universal joints to move the end effector up and down, and side to side. They’re extremely fast and are a great design for 3D printers and pick and place machines, but they do have a limitation: the tip of a single Delta can not move much further than the base of the robot.

By adding more parallelograms to a Delta, [Aad] greatly increases working volume of a his robots. One of the suggested uses for this style of bot is for palletizers, demonstrated in the video below by stacking Jenga blocks. There is another very interesting application: legs. There’s footage of a small, simple triple Delta scooting around the floor, supported by wire training wheels below. It makes a good cat toy, but we’d love to see a bipedal robot with this style of legs.

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Paper Plane Machine Gun

Paper Plane Folding Machine Gun Is A Mechanical Marvel

October 9, 2014 by 44 Comments

A German man has just finished a very impressive Paper Airplane Machine Gun, or a Papierflieger-Maschinenpistole, which just sounds so much cooler. It actually takes a stack of paper, folds it into paper air planes and shoots them.

The device takes a stack of what looks like post-card size paper in the “clip”, forms them into paper air planes by a series of rollers and folding edges and then launches them out of the end. A cheap electric screwdriver powers the entire drive train, which allows him to shoot around 20 planes per minute (PPM?).

Sadly there’s really not too much information on how it works, nor the files to reproduce it. [Papierfliegerei], as he goes by on YouTube, decided to build this awesome contraption to show off just what 3D printers are capable of these days. He designed the whole thing in 3D CAD and had many of the parts printed off at a 3D printing company called fabberhouse.de, while the rest of the components are off the shelf.

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Hackaday 10th Anniversary: Hacking Your Way To NASA

October 9, 2014 by 2 Comments

[Steve] drives spacecraft for a living. As an engineer at the Jet Propulsion Laboratory, he’s guided probes to comets, asteroids, Mars, and Jupiter, figured out what happens when telemetry from these probes starts looking weird, and fills the role of the Space Hippy whenever NASA needs some unofficial PR.

Like most people who are impossibly cool, [Steve]’s career isn’t something he actively pursued since childhood. Rather, it’s something that fell in his lap. With qualifications like building a robotic computer to typewriter interface, a custom in-car navigation system in the late 80s, and a lot of work with an Amiga, we can see where [Steve] got his skills.

The earliest ‘hack’ [Steve] can remember was just that – an ugly, poorly welded sidecar for his bicycle made in his early teens. From there, he graduated to Lasertag landmines, Tesla coils, and building camera rigs, including a little bit of work on Octopussy, and a rig for a Miata. It helps when your dad is a cinematographer, it seems.

In college, [Steve] used his experience with 6502 assembler to create one of the first computerized lighting controllers (pre-DMX). After reading a biography on [Buzz Aldrin], [Steve] realized doing his thesis on orbital rendezvous would at least be interesting, if not an exceptionally good way to get the attention of NASA.

Around this time, [Steve] ran into an engineering firm that was developing, ‘something like Mathematica’ for the Apple II, and knowing 6502 assembly got him in the door. This company was also working to get the GPS constellation up and running, and [Steve]’s thesis on orbital mechanics eventually got him a job at JPL.

There’s several lifetimes worth of hacks and builds [Steve] went over at the end of his talk. The highlights include a C64 navigation system for a VW bug, a water drop high voltage machine, and a video editing system built from a few optical encoders. This experience with hacking and modding has served him well at work, too: when the star sensor for Deep Space 1 failed, [Steve] and his coworkers used the science camera as a stand in navigation aid.

One final note: Yes, I asked [Steve] if he played Kerbal Space Program. He’s heard of it, but hasn’t spent much time in it. He was impressed with it, though, and we’ll get a video of him flying around the Jool system eventually.