Brachiograph: A Simple And Cheap Pen-Plotter

October 30, 2019 by Maya Posch 7 Comments

The BrachiGraph project consists out of two parts, the hardware design for a servo-driven drawing arm (pen plotter) and software utilities (written in Python) that allow the drawing arm’s servos to be controlled in order to convert a bitmap image into a collection of lines that can be used to draw an image resembling the original, in a variety of styles. All of the software and designs needed to make your own version can be found on the Github page for the project.

Considering an estimated €14 worth of materials for the project, the produced results are nothing short of amazing, even if the principles behind the project go back to the Ancient Greek , of course. The basic hardware is that of a pantograph, which provides the basic clues for how the servos on the plotter arm are being driven.

The main achievement here is definitely that of minimalism, with three dirt-cheap SG-90 microservos along with some bits of wood, a clothes-peg or equivalent, and of course a pen providing a functional plotter that anyone can assemble on a slow Sunday afternoon from random bits lying around the workshop.

Turntable Spins Color And Sound Together

October 27, 2019 by Erin Pinheiro 5 Comments

If you can’t grow your own synesthesia, buying electronics to do it for you is fine. Such is the case with the CHROMATIC by [Xavier Gazon], an artist who turns all kinds of electronics into circuit-bent musical art pieces. His project turns an old Philips Music 5120 turntable into a colorful MIDI sequencer, inspired by older 20th century instruments such as the Optophonic Piano and the Luminaphone.

The CHROMATIC uses colored pucks placed on a converted turntable to perform a looping sequence of chords in a given musical scale, generating MIDI data as output. Where its inspirations used primitive optics as their medium, this project employs a Teensy microcontroller and two modern optical sensors to do the work. One of these is a simple infrared sensor which tracks a white spot on the edge of the turntable, generating a MIDI clock signal to keep everything quantized and in sync. The other is a color sensor mounted on the tone arm, which can tell what color it sees and the height of the arm from the turntable.

While the instrument is still in beta testing phase details on how notes are generated aren’t yet given, though the general idea is that they are dictated by the color the tone arm sees and its position above the platter. Moving the tone arm changes which pucks it tracks, and the speed of the turntable can also be adjusted, changing how the melody sounds.

The CHROMATIC is a very interesting project, but it’s not the first optical-based turntable hack we’ve seen here. We’ve also seen a much weirder use for a color sensor, too. Check out the video of this one in action after the break.

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Faux Cow Munches Faux Grass On A Faux Roomba

October 24, 2019 by Anool Mahidharia 13 Comments

Out in the countryside, having a cow or to two wouldn’t be a big deal. You can have a cattle shed full of them, and no one will bat an eyelid. But what if you’re living in the big city and have no need of pet dogs or cats, but a pet cow. It wouldn’t be easy getting it to ride in the elevator, and you’d have a high chance of being very, very unpopular in the neighbourhood. [Dane & Nicole], aka [8 Bits and a Byte] were undaunted though, and built the Moomba – the Cow Roomba to keep them company in their small city apartment.

The main platform is built from a few pieces of lumber and since it needs to look like a Roomba, cut in a circular shape. Locomotion comes from two DC geared motors, and a third swivel free wheel, all attached directly to the wooden frame. The motors get their 12V juice from eight “AA” batteries. The free range bovine also needs some smarts to allow it to roam at will. For this, it uses a Raspberry Pi powered by a power bank. The Pi drives a 2-channel relay board which controls the voltage applied to the two motors. Unfortunately, this prevents the Moomba from backing out if it gets stuck at a dead end. For anyone else trying to build this it should be easy enough to fix with an electronic speed controller or even by adding a second 2-channel relay board which can reverse the voltage applied to the motors. The Moomba needs to “Moo” when it feels like, so the Raspberry Pi streams a prerecorded mp3 audio clip to a pair of USB speakers.

If you see the video after the break, you’ll notice that making the Moomba sentient is a simple matter of doing “ctrl+C” and “ctrl+V” and you’re good to go. The python code is straight forward, doing one of four actions – move forward, turn left, turn right or play audio. The code picks a random number from 0 to 3, and then performs the action associated with that number. Finally, as an added bonus, the Moomba gets a lush carpet of artificial green grass and it’s free to roam the range.

At first sight, many may quip “where’s the hack” ? But simple, easy to execute projects like these are ideal for getting younglings started down the path to hacking, with adult supervision. The final result may appear frivolous, but it’ll excite young minds as they learn from watching.

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Daisy Chained Seven Segment Art Display

October 23, 2019 by Sharon Lin 8 Comments

This seven segment art display makes use of a 81 seven segment red common cathode LED displays. The LEDs are arranged onto 100x100mm boards that each contain an Arduino Nano and 9 seven segment displays, daisy chained through three-pin headers located on the sides of the boards. The pins (power, ground, and serial) provide the signals necessary for propagating a program across each of the connected boards.

The first board – with two Arduino Nanos – sends instructions for which digits to light and drives the display, sending the instructions over to the next board on the chain.

In a multiplexed arrangement, a single Arduino Nano is able to drive up to 12 seven segment displays, but only 9 needed to be driven for the program, keeping D13’s built in LED and the serial pins free. Since no resistors are featured on the boards, current limiting is done through software. This was inspired by the Bubble LED displays on the Sinclair Scientific Calculator, and was done in order to achieve a greater brightness by controlling the current through the duty cycle.

The time between digits lighting up is 2ms, giving them some time to cool down. The animations in the demos featured falling and incrementing digits, as well as a random number generator using a linear feedback shift register.

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Portrait Painter Turns G-Code Into Artworks

October 11, 2019 by Lewin Day 5 Comments

Portrait painting is, by and large, a human endeavour. But, like any and all skills, there are machines ready and willing to take a crack at it. [Jose Salatino] has built just such a machine, and the results are impressive.

Samples of the artwork created by [Jose’s] portrait painter.

[Jose’s] portrait painter relies on a Cartesian CNC setup, with an X-Y gantry fitted with a retractable brush carrier. The carrier holds four brushes, allowing the device to paint with different sized strokes as per the artistic requirements. An algorithm is used to turn images into a series of brushstrokes, which are then turned into G-code to drive the system. Colors are mixed just like a human painter would, with the brush dipping into a series of paint pots. Using the hue-saturation-brightness (HSB) color system makes this easy.

While it’s much slower than your average printer, the goal here isn’t to create photorealistic images, but to create something with artistic appeal. The artworks painted by the ‘bot have a remarkable likeness to oil paintings by human artists, thanks to using similar techniques. We’re sure [Jose’s] experience as an oil painter helped out here, too.

We’ve seen other ‘bots produce custom artworks before, too. Video after the break.

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Designing Sci-Fi Hack Chat

October 7, 2019 by Dan Maloney 9 Comments

Join us on Wednesday, October 9 at noon Pacific for the Designing Sci-Fi Hack Chat with Seth Molson!

We all know the feeling of watching a movie set in a galaxy far, far away and seeing something that makes us say, “That’s not realistic at all!” The irony of watching human actors dressed up as alien creatures prancing across a fantasy landscape and expecting realism is lost on us as we willingly suspend disbelief in order to get into the story; seeing something in that artificial world that looks cheesy or goofy can shock you out of that state and ruin the compact between filmmaker and audience.

Perhaps nowhere do things get riskier for filmmakers than the design of the user interfaces of sci-fi and fantasy sets. Be they the control panels of spacecraft, consoles for futuristic computers, or even simply the screens of phones that are yet to be, sci-fi UI design can make or break a movie. The job of designing a sci-fi set used to be as simple as wiring up strings of blinkenlights; now, the job falls to a dedicated artist called a Playback Designer who can create something that looks fresh and new but still plausible to audiences used to interacting with technology that earlier generations couldn’t have dreamed of.

Seth Molson is one such artist, and you’ve probably seen some of his work on shows such as Timeless, Stargate Universe, and recently Netflix’s reboot of Lost in Space. When tasked to deliver control panels for spacecraft and systems that exist only in a writer’s mind, Seth sits down with graphics and animation software to make it happen.

Join us as we take a look behind the scenes with Seth and find out exactly what it’s like to be a Playback Designer. Find out what Seth’s toolchain looks like, how he interacts with the rest of the production design crew to come up with a consistent and believable look and feel for interfaces, and what it’s like to design futures that only exist — for now — in someone’s imagination.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, October 9 at 12:00 PM Pacific time. If time zones have got you down, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

When Engineering, Fine Art, And ASMR Collide

October 3, 2019 by Tom Nardi 8 Comments

The success that [Julian Baumgartner] has found on YouTube is a perfect example of all that’s weird and wonderful about the platform. His videos, which show in utterly engrossing detail the painstaking work that goes into restoring and conserving pieces of fine art, have been boosted in popularity by YouTube’s Autonomous Sensory Meridian Response (ASMR) subculture thanks to his soft spoken narration. But his latest video came as something of a surprise to lovers of oil paintings and “tingles” alike, as it revealed that he’s also more than capable of scratch building his own equipment.

Anyone who’s been following his incredible restorations will be familiar with his heated suction table, which is used to treat various maladies a canvas may be suffering from. For example, by holding it at a sufficiently high temperature for days on end, moisture can be driven out as the piece is simultaneously smoothed and flattened by the force of the vacuum. But as [Julian] explains in the video after the break, the heated suction table he’s been using up to this point had been built years ago by his late father and was starting to show its age. After a recent failure had left him temporarily without this important tool, he decided to design and build his own fault-tolerant replacement.

The table itself is built with a material well known to the readers of Hackaday: aluminum extrusion. As [Julian] constructs the twelve legged behemoth, he extols the many virtues of working with 4040 extrusion compared to something like wood. He then moves on to plotting out and creating the control panel for the table with the sort of zeal and attention to detail that you’d expect from a literal artist. With the skeleton of the panel complete, he then begins wiring everything up.

Underneath the table’s 10 foot long surface of 6061 aluminum are 6 silicone heat pads, each rated for 1,500 watts. These are arranged into three separate “zones” for redundancy, each powered by a Crydom CKRD2420 solid state relay connected to a Autonics TC4M-14R temperature controller. Each zone also gets its own thermocouple, which [Julian] carefully bonds to the aluminum bed with thermally conductive epoxy. Finally, a Gast 0523-V4-G588NDX vacuum pump is modified so it can be activated with the flick of a switch on the control panel.

What we like most about this project is that it’s more than just a piece of equipment that [Julian] will use in his videos. He’s also released the wiring diagram and Bill of Materials for the table on his website, which combined with the comprehensive build video, means this table can be replicated by other conservators. Whether it’s restoring the fine details on Matchbox cars or recreating woodworking tools from the 18th century, we’re always excited to see people put their heart into something they’re truly passionate about.

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