We’ve never seen someone build a plotter out of buzzwords, but [roxen] did a really good job of it. The idea is simple, place the plotter over a sheet of paper, open a website, draw, and watch the plotter go. Check out the video below the break.
The user draws in an HTML5 Canvas object which is read by a Java Web Server. From there it gets converted to serial commands for an Arduino which controls the steppers with two EasyDrivers.
The build itself is really nice. It perfectly meets the mechanical requirements of a pen plotter without a lot of fluff. The overall frame is T-shaped, for the x- and y-axis. The movements are produced by two steppers and acetal rack and pinion sets. The pen is lifted up and down by a hobby servo.
Preserved railways are now an established part of the tourist itinerary. It doesn’t matter if you call it a railroad, railway, chemin de fer, Eisenbahn or whatever, the chances are that somewhere near you there will be a line rescued from dereliction on which you can spend a Saturday afternoon in vintage rolling stock being hauled by a locomotive long ago withdrawn from regular service. They are established enough to have become an industry in their own right, with the full range of support services to maintain hundred-year-old machinery and even build entire new locomotives.
So we’ve become used to seeing preserved railways in a state of polished perfection. Sometimes a little too perfect, there was a wry observation in a recent BBC documentary on the subject that a typical British preserved railway represents an average day in the 1950s when the Queen was about to visit. Anyone who lived through that era will tell you the reality was a little different, how run down the system was after World War II and just how dirty everything became when exposed to decades of continuous coal smoke.
A particularly worn-out section of railway in those days could be found at Tywyn, on the Welsh coast. A 2’3″ narrow-gauge line built in the 1860s to serve a slate quarry and provide a passenger service to local communities, the Tal-y-Llyn Railway (Welsh pronunciation help) had been in continuous decline for decades and on the death of its owner in 1950 faced closure. With only one of its two locomotives operational and its track in a parlous state it attracted the attention of the author Tom Rolt, already famous for kick-starting the preservation of Britain’s inland waterway system. A preservation society was formed, and in a joint enterprise with the former owner’s estate the line was saved. The world’s first preserved railway had commenced operations.
“Lawnmower” Locomotive in 1952 [Source: talyllyn.co.uk]In a country reeling from the economic effects of fighting a world war there was no infrastructure for a group of enthusiasts rescuing a near-derelict railway. Nobody had ever done this before, there was no body of expertise and certainly no handy suppliers to call when parts were required. To rebuild their line the Tal-y-Llyn volunteers had to reach into their own well of initiative gained over the “Make do and Mend” war years and build their own way out of any challenges they encountered. In case you were wondering what the relevance to Hackaday readers has been in the last few paragraphs there’s your answer: what would you do if you were handed seven and a quarter miles of run-down track and a single barely serviceable locomotive that is one of the oldest in the world still running?
We are fortunate that in 1953 an American film maker, Carson “Kit” Davidson, visited the line, and through his affectionate short film we have a portrayal of the railway’s state in the early stages of preservation. When the footage was shot they had secured a second serviceable locomotive courtesy of the nearby and recently closed Corris Railway, but had yet to replace the majority of the worn-out and overgrown track. It’s a treat to watch, and sets the stage very well for the home-made machinery that is to follow.
Expensive laser cutters have a 3D engraving mode that varies the laser power as it is etching a design, to create a 3D effect. [Benjamin Alderson] figured this could be replicated on a cheap Chinese laser — so he made his own program called SmoothCarve.
He’s got one of those extra cheap blue-box 40W CO2 lasers you can nab off eBay for around $600-$800, but he’s replaced the control board with a SmoothieBoard as an easy upgrade. He wrote the program in MatLab to analyze a grey scale image and then assign power levels to the different shades of grey. You can see the software and try it yourself over at his GitHub.
The resulting application is pretty handy — watch it carve the Jolly RancherWrencher after the break!
Hernando Barragán is the grandfather of Arduino of whom you’ve never heard. And after years now of being basically silent on the issue of attribution, he’s decided to get some of his grudges off his chest and clear the air around Wiring and Arduino. It’s a long read, and at times a little bitter, but if you’ve been following the development of the Arduino vs Arduino debacle, it’s an important piece in the puzzle.
Wiring, in case you don’t know, is where digitalWrite() and company come from. Maybe even more importantly, Wiring basically incubated the idea of building a microcontroller-based hardware controller platform that was simple enough to program that it could be used by artists. Indeed, it was intended to be the physical counterpart to Processing, a visual programming language for art. We’ve always wondered about the relationship between Wiring and Arduino, and it’s good to hear the Wiring side of the story. (We actually interviewed Barragán earlier this year, and he asked that we hold off until he published his side of things on the web.)
The short version is that Arduino was basically a fork of the Wiring software, re-branded and running on a physical platform that borrowed a lot from the Wiring boards. Whether or not this is legal or even moral is not an issue — Wiring was developed fully open-source, both software and hardware, so it was Massimo Banzi’s to copy as much as anyone else’s. But given that Arduino started off as essentially a re-branded Wiring (with code ported to a trivially different microcontroller), you’d be forgiven for thinking that somewhat more acknowledgement than “derives from Wiring” was appropriate.
See what we mean?
The story of Arduino, from Barragán’s perspective, is actually a classic tragedy: student comes up with a really big idea, and one of his professors takes credit for it and runs with it.
[Jesus Echavarria] sent us a link to this cute little tool that he’s built. It’s a dual USB-to-I2C-or-UART adapter, with a few more oddball features thrown in for good measure. If you were electronics Batman, you’d have this on your utility belt.
[Jesus] originally designed the board because he wanted to sniff a bi-directional UART conversation using his computer, and get it all done in inexpensive hardware with minimal fuss. So he looked to the Microchip MCP2221 chip, which is an inexpensive USB to serial and I2C chip, but with some extras. In particular, it’s got four GPIOs, a ten-bit ADC and a five-bit DAC with selectable reference voltage, and it’s all controllable over USB. And [Jesus]’s board has two of them.
Implementing USB on a microcontroller isn’t always that much fun, so we can see why he took the straight-ahead hardware approach. And as a side benefit, he gets all the other kooky functionalities that the chip brings. And we have been introduced to what looks like a neat chip to use in USB and microcontroller projects. We’re going to put one in our next random chip order.
[Brainsmoke] had a simple plan. Make a quadcopter with lots of addressable LEDs.
Not just a normal quadcopter with ugly festoons of LED tape though. [Brainsmoke] wanted to put his LEDs in a ball. Thus was born the polyhedrone, the idea of a flying deltoidal hexecontahedron covered as you might expect with all those addressable LEDs.
A Catalan solid makes a good choice for the homebrew polyhedron builder because its faces are all identical. Thus if you are making PCBs to carry LEDs, for example, you need only create a single PCB design to use on all faces. A bit of work in KiCAD, and a single face design with interlocking edges was ready. The boards were tested, a wiring layout was worked out, and the polyhedron was assembled.
But [Brainsmoke] didn’t stop there. He produced a flight case for the polyhedron, in the form of a larger polyhedron from what looks like lasercut thin ply.
Having a finished polyhedron, the next thing was to hook up a Raspberry Pi and write some software. First in Python, then in Go.
The results are simply stunning. If the mathematics and construction of a polyhedron were not enough to make this project worth a second look, then the gallery of images should be enough. You’ll notice that this is ostensibly a quadcopter project, yet no mention of flying has been made on this page. That’s because this is still a work in progress at Tech Inc Amsterdam, and there is more to come. But it honestly doesn’t matter if this project never moves a millimeter off the ground, as far as we are concerned [Brainsmoke] has created a superbly built thing of beauty in its own right, and we like that.
As you might expect, this is just the latest of many projects featured here that have involved addressable LEDs or quadcopters. Of note among them is this LED polyhedron that cleverly closes in all its bits, and this LED-equipped quadcopter that generates very pleasing patterns with a hi-res cross of pixels.
Most people play games for entertainment. Hackers build robots to play games for entertainment. That’s what [piandchips] did. He used a Raspberry Pi and a MeArm kit to build a Connect 4-playing robot. The robot–named 4-Bot–has to do two things: the first is it has to be able to manipulate the pieces. Secondly, it has to be able to see the board. The MeArm imbues 4-Bot with the manipulation ability, and a clever scanning system does the trick.
!["Lawnmower" Locomotive in 1952 [Source: talyllyn.co.uk]](https://hackaday.com/wp-content/uploads/2016/03/jbs-1-2kw.jpg?w=400)
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The results are simply stunning. If the mathematics and construction of a polyhedron were not enough to make this project worth a second look, then the 
