The HellZXchreiber

HellZXschreiber

Hellschreiber – German for ‘light pen’ – was developed in the 20s as a way to transmit text in a way that was much more robust than the teletypes of the time. These devices were used to great effect by the Germans in WWII, and later became popular with wire services and was used until the 80s. The fax machine then happened, and no one really cared about Hellschreiber, save for a few plucky amateur radio enthusiasts.

In the early 90s, a few of these amateur radio enthusiasts realized they could use their personal computers to communicate with this extremely simple protocol that’s also very resilient against interference and weak radio links. [Danjovic] is following in their footsteps by decoding Hellschreiber on an old ZX Spectrum clone.

[Danjovic] tested his code with the sound sample found in the Hallschreiber wiki article and some text generated by Fldigi. Everything works beautifully, an [Dan] can even change the intensity of the text with the volume control – a very useful feature should the HellZXchreiber ever make it out into the field.

Source and image files available for all you strange Speccy fans. Everyone else can check out the videos below.

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Automated Bed Leveling For 3D Printers Is Now Solved

bed

The latest and greatest feature for 3D printers – besides being closed source, having no meaningful technical specs, and being on track towards pulling in $10 Million on a Kickstarter – is automated bed leveling. This amazingly useful feature makes sure your prints have proper adhesion to the bed, reduce print errors, and put even inexpensive printers into the realm of extremely expensive professional machines. Automated bed leveling has been extremely hard to implement in the past, but now [Scottbee] has it figured out with a working prototype on his Makerbot Replicator 2X.

Earlier attempts at automated bed leveling used some sort of probe on the tool head to measure the build plate, calculate its flatness and orientation in space, and compensate for any tilt in software. [Scottbee]‘s solution to the problem took a different tack: instead of trying to compensate for any odd orientation of the build surface in software, he’s simply making the bed level with a series of springs and cam locks.

[Scottbee]‘s device levitates the build plate on three springs, and replaces the jack screws with three “gimballing pins” and pin locks. With the pin locks disengaged, the bed plate is pressed down with the printer’s nozzle. By moving the extruder across the build plate and locking the pins in place one by one, [Scottbee]‘s device defines the plane of the build plate along three points. This makes the build platform parallel to the extruder nozzle, and also has a nice benefit of setting the distance from the build platform to the nozzle precisely with incredible repeatability.

The mechanics of locking the three gimballing pins in place  only requires a single DC gear motor, driven by an extra fan output on the Makerbot’s electronics. It’s simple, and with a bit of rework, it looks like most of the device could also be 3D printed.

An awful lot of RepRaps and 3D printers out there already use three points to attach the build plate to a frame. With a little bit of effort, this same technique could be ported and made a bit more generic than the Makerbot-based build seen above. It’s amazingly simple, and we can’t wait to see this applied to a normal RepRap.

Thanks [Josh] for the tip.

Fixing Apple TV’s Terrible UI

IR

Despite Apple’s unfailing dedication to UI, they still sometimes manage to put out some stinkers. The latest of these is the ‘keyboard’ for the search interface in the Apple TV. It’s an alphabetical keyboard, laid out in a square with the obvious frustration that goes along with that terrible idea. [Lasse] was frustrated with this design and realized searching anything with the Apple TV IR remote is a pain. His solution was to build his own version of the Apple TV remote with a web interface, powered by an Arduino.

Inspired by the Apple Remote Arduino Shield we featured a few years ago, [Lasse] stuck an IR LED int the pins of Arduino with an Ethernet shield, current limiting resistors be damned. The web UI is the innovative part of this build. He’s hosting a simple website on the Arduino that allows him to type – with a real keyboard – a search query into the website, and have the Arduino take care of moving the Apple TV cursor around to select each letter.

The web UI has all the features found on the Apple TV remote, including the swipe gestures, and has a really slick brushed metal texture to boot. You can check out the video of [Lasse]‘s project typing text into an Apple TV hilariously fast below.

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Bare-metal Programming On The Teensy 3

Teensy

The Teensy 3.x series of boards are amazing pieces of work, with a tiny, breadboard-friendly  footprint, an improbable amount of IO pins, and a powerful processor, all for under $20. [Karl Lunt] loves nearly all the features of the Teensy 3, except for one: the Arduino IDE. Yes, the most terrible, most popular IDE in existence. To fix this problem, [Karl] set up a bare-metal development environment, and lucky us, he’s chosen to share it with us.

[Karl] is using CodeBench Lite for the compiler, linker, assembler, and all that other gcc fun, but the CodeSourcery suite doesn’t have an IDE. Visual Studio 2008 Express is [Karl]‘s environment of choice, but just about every other IDE out there will do the same job. Of course a make utility will be needed, and grabbing the docs for the Freescale K20 microcontroller wouldn’t be a bad idea, either.

The end result is [Karl] being able to develop for the Teensy 3.X with the IDE of his choice. He was able to quickly set up a ‘blink a LED’ program with the new toolchain, although uploading the files to the Teensy does require the Teensy Loader app.

 

Electron Beam Control In A Scanning Electron Microscope

Electron

A few years ago [Ben Krasnow] built a scanning electron microscope from a few parts he had sitting around. He’s done a few overviews of how he built his SEM, but now he’s put up a great video on how to control electrons, focus them into a point, and scan a sample.

The basic idea behind a scanning electron microscope is to shoot electrons down a tube, focus them into a point, and scan a conductive sample and detect the secondary electrons shot off the sample and display them on an oscilloscope. [Ben] is generating electrons with a small tungsten filament at the top of his electron ‘stack’. Being like charged, these electrons naturally fan out, so a good bit of electron optics are required to get a small point.

Focusing is done through a series of pinholes and electrostatic deflectors, much like you’d see in an old oscilloscope CRT. In the video, you can see [Ben] shooting electrons and displaying a Christmas tree graphic  onto a piece of phosphor-coated glass. He has a pretty big scanning area in his SEM, more than enough to look at a few chips, wafers, and whatever other crazy stuff is coming out of [Ben]‘s lab.

Video below, along with the three-year-old overview of the entire microscope.

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Hackerspace Tour: IXR in Wall, NJ

IXR2

Hackaday took a little trip out to Wall, NJ last weekend for the Vintage Computer Festival 9.1 East. The event was held at Camp Evans, a former US military installation that can only be described as, ‘The DARPA of a century ago”. This is the site of a Marconi transmitter and the place where [Edwin Armstrong] developed the regenerative receiver a little more than 100 years ago.

There’s a lot more to Camp Evans than a vintage computer festival once a year – it’s also home to MARCH, the Mid-Atlantic Retro Computing Hobbyists, InfoAge, a retro technology museum, and IXR, the Institute for eXploratory Research, a hackerspace located in the old telecom building at Camp Evans.

In our video tour, [Joe Wilkes] takes us around the shop, showing off their equipment and tools. Unlike most of our hackerspace tours, we couldn’t find a Makerbot sitting disused on a bookshelf anywhere, but the space did have a Solidoodle 3D printer, a Shapeoko 2 CNC machine under construction, and enough hand tools to bring any project to fruition.

There were a few oddities in IXR compared to the other hackerspaces we’ve been to. First is an inordinate amount of synths, keyboards, and other MIDI gear. [Joe] didn’t know what these were for, so we’ll leave that explanation for an IXR member in the comments of this post. There was also a small supply of random components for sale (and on display). Most of the merch was from Adafruit, and it seems like a great way to have that one part I need to finish this build for members while providing a little bit of beer money for the space.

Pics and video below.

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Printing In Three Dimensions, For Real This Time

topo

3D printers don’t continuously print in three dimensions – they print one layer, then another, then another. This is true for every single 3D printing technology, but now Topolabs has a very interesting technique that changes that. They’re printing in three dimensions by moving in the Z axis while also printing in the X and Y axes.

The basic idea behind Topolabs’ software is to print a support block, then print an object right on top of the support. The support block can be curved and convex, and the finished product follows the contours of the solid support block. Unlike ‘printing with supports’, the printer extrudes along the X, Y, and Z axes, which should make the finished product much, much stronger.

There are a few drawbacks to the technique – a release agent must be applied to the top of the support block. In the video below, Topolabs is using Kapton, but hair spray or glue sticks will also work. There’s also a limit to how steep an incline a printer can print, determined by the size of the extruder nozzle. Lastly, this technique would be much better suited for a delta-style bot, but the team is getting very good results with a normal Cartesian bot.

You can see a few videos of the Topolabs printing technique below.

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