The March Toward A DIY Metal 3D Printer

July 26, 2019 by Sharon Lin 20 Comments

[Hyna] has spent seven years working with electron microscopes and five years with 3D printers. Now the goal is to combine expertise from both realms into a metal 3D printer based on electron-beam melting (EBM). The concept is something of an all-in-one device that combines traits of an electron beam welder, an FDM 3D printer, and an electron microscope. While under high vacuum, an electron beam will be used to fuse metal (either a wire or a powder) to build up objects layer by layer. That end goal is still in the future, but [Hyna] has made significant progress on the vacuum chamber and the high voltage system.

The device is built around a structure made of 80/20 extruded aluminum framing. The main platform showcases an electron gun, encased within a glass jar that is further encased within a metal mesh to prevent the glass from spreading too far in the event of an implosion.

Vacuum chamber enclosed in mesh (new gasket shown)

Mold for making silicone gasket

The design of the home-brewed high-voltage power supply involves an isolation transformer (designed to 60kV), using a half-bridge topology to prevent high leakage inductance. The transformer is connected to a buck converter for filament heating and a step up. The mains of the system are also connected to a voltage converter, which can be current-fed or voltage-fed to operate as either an electron beam welder or scanning electron microscope (SEM). During operation, the power supply connects to a 24V input and delivers the beam through a Wehnelt cylinder, an electrode opposite an anode that focuses and controls the electron beam. The entire system is currently being driven by an FPGA and STM32.

The vacuum enclosure itself is quite far along. [Hyna] milled a board with two outputs for a solid state relay (SSR) to a 230V pre-vacuum pump and a 230V pre-vacuum pump valve, two outputs for vent valves, and inputs from a Piranni gauge and a Cold Cathode Gauge, as well as a port for a TMP controller. After demoing the project at Maker Faire Prague, [Hyna] went back and milled a mold for a silicone gasket, a better vacuum seal for the electron beam.

While we’ve heard a lot about different metal 3D printing methods, this is the first time we’ve seen an EBM project outside of industry. And this may be the first to attempt to combine three separate uses for an HV electron beam into the same build.

Retrotechtacular: The Floppy Disk Orphaned By Linux

July 26, 2019 by Jenny List 105 Comments

About a week ago, Linus Torvalds made a software commit which has an air about it of the end of an era. The code in question contains a few patches to the driver for native floppy disc controllers. What makes it worthy of note is that he remarks that the floppy driver is now orphaned. Its maintainer no longer has working floppy hardware upon which to test the software, and Linus remarks that “I think the driver can be considered pretty much dead from an actual hardware standpoint“, though he does point out that active support remains for USB floppy drives.

It’s a very reasonable view to have arrived at because outside the realm of retrocomputing the physical rather than virtual floppy disk has all but disappeared. It’s well over a decade since they ceased to be fitted to desktop and laptop computers, and where once they were a staple of any office they now exist only in the “save” icon on your wordprocessor. The floppy is dead, and has been for a long time.

The save icon in LibreOffice and other desktop software is probably the last place the floppy exerts a hold over us.

Still, Linus’ quiet announcement comes as a minor jolt to anyone of A Certain Age for whom the floppy disk and the computer were once inseparable. When your digital life resided not in your phone or on the cloud but in a plastic box of floppies, those disks meant something. There was a social impact to the floppy as well as a technological one, they were a physical token that could contain your treasured ephemeral possessions, a modern-day keepsake locket for the digital age. We may have stopped using them over a decade ago, but somehow they are still a part of our computing DNA.

So while for some of you the Retrotechtacular series is about rare and unusual technology from years past, it’s time to take a look at something ubiquitous that we all think we know. Where did the floppy disk come from, where is it still with us, and aside from that save icon what legacies has it bestowed upon us?

Continue reading “Retrotechtacular: The Floppy Disk Orphaned By Linux” →

Hackaday Podcast 028: Brain Skepticism Turned Up To 11, Web Browsing In ’69, Verilog For 7400 Logic, 3D Printing In Particle Board

July 26, 2019 by Mike Szczys No comments

Hackaday Editors Mike Szczys and Elliot Williams cover the most interesting hacks over the past week. So much talk of putting computers in touch with our brains has us skeptical on both tech and timeline. We celebrated the 40th Anniversary of the Walkman, but the headphones are the real star. Plus, Verilog isn’t just for FPGAs, you can synthesize 7400 circuits too! Elliot is enamored of an additive/subtractive printing process that uses particle board, and we discuss a couple of takes on hybrid-powered drones.

Take a look at the links below if you want to follow along, and as always tell us what you think about this episode in the comments!

Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!

Direct download (60 MB or so.)

Continue reading “Hackaday Podcast 028: Brain Skepticism Turned Up To 11, Web Browsing In ’69, Verilog For 7400 Logic, 3D Printing In Particle Board” →

Cheap Speakers Sound Great In A Proper Enclosure

July 26, 2019 by Lewin Day 31 Comments

It’s possible to pick up a low-cost set of speakers for a few dollars, but by and large, you don’t get a lot of quality for your money. Expect a small pair of drivers, with tinny sound and ugly noises from the enclosure’s cheap materials. [JSK-koubou] has shown us, however, that these speakers can become so much more.

The internal structure helps improve the frequency response.

In this case at least, the basic speaker drivers and electronics inside were passable. Harvesting these, the builder then proceeds to create a stunning pair of tuned wooden enclosures for the speakers. This is achieved with a routing template, large blocks of wood and plenty of elbow grease.

The internal structure makes a huge difference to the bass response of the speakers, allowing them to far more faithfully recreate the music under test. Thanks to the artisan-level craftsmanship, the final product is stunning to look at, too. It’s impressive just how well a cheap pair of drivers can perform with a proper enclosure, and of course, there’s nothing to stop an even better set of drivers being installed, either.

When building your own speakers, your creativity is the limit. Video after the break.

Continue reading “Cheap Speakers Sound Great In A Proper Enclosure” →

This Week In Security: Selfblow, Encryption Backdoors, Killer Apps, And The VLC Apocalypse That Wasn’t

July 26, 2019 by Jonathan Bennett 18 Comments

Selfblow (Don’t google that at work, by the way) is a clever exploit by [Balázs Triszka] that affects every Nvidia Tegra device using the nvtboot bootloader — just about all of them except the Nintendo Switch. It’s CVE 2019-5680, and rated at an 8.2 according to Nvidia, but that high CVE rating isn’t entirely reflective of the reality of the situation. Taking advantage of the vulnerability means writing to the boot device, which requires root access, as well as a kernel flag set to expose the boot partitions to userspace. This vulnerability was discovered as part of an effort by [Balázs] and other LineageOS developers to build an open source bootloader for Nvidia Tegra devices.

The Tegra boot process is a bit different, having several stages and a dedicated Boot and Power Management CPU (BPMP). A zero-stage ROM loads nvtboot to memory and starts it executing on the BPMP. One of the tasks of nvtboot is to verify the signature of the next bootloader step, nvtboot-cpu. The file size and memory location are embedded in the nvtboot-cpu header. There are two problems here that together make this vulnerability possible. The first is that the bootloader binary is loaded to its final memory location before the signature verification is performed. The code is written to validate the bootloader signature before starting it executing on the primary CPU, so all is well, right? Continue reading “This Week In Security: Selfblow, Encryption Backdoors, Killer Apps, And The VLC Apocalypse That Wasn’t” →

Installing Android On Your Nintendo Switch, Because Why Not?

July 26, 2019 by Maya Posch 19 Comments

In a continuing trend of ‘but does it run Android?’, enterprising folk over at the XDA-Developers forum have found a way to get LineageOS (the successor to CyanogenMod) installed and running on the Nintendo Switch using Switchroot source code. Promising to release the necessary files to replicate this effort has obviously made other people at XDA-Developers forum as well as on Reddit rather excited.

As for the question of ‘why?’, one has to remember that internally the Nintendo Switch is an Nvidia Tegra X1-based system with a Maxwell GPU, making it definitely one of the nicer ARM-based portable systems out there if one wants to do some Android-based gaming. Even better, the entire Nvidia Shield TV-derived ROM runs from the SD card, so just popping out this SD card is sufficient to return to playing Switch games.

Currently a few nagging issues still have to be worked out with this ROM, such as touchscreen issues, sleep mode not working, auto-rotation not working as communication with the sensor needs to be figured out, and so on. This should make it clear that it won’t be a production ready piece of software, but definitely something that should be used at your own risk.

While it shouldn’t harm the Switch, one should probably not try it on a Switch one cares deeply about. Just in case.

HDMI From Your Arduino

July 26, 2019 by Jenny List 29 Comments

Creating a video signal from a computer, a job that once required significant extra hardware, is now a done deal with a typical modern microcontroller. We’ve shown you more NTSC, PAL, and VGA projects than you can shake a stick at over the years. Creating an HDMI video signal however is not so straightforward. It’s not a loosely defined analogue standard but a tightly controlled digital one upon which the clever hacks that eke full colour composite video from a single digital I/O pin will have little effect. Surely creating them from a simple microcontroller will be impossible! Not according to [techtoys], who has created an Arduino shield that creates an HDMI output from an SPI control input.

At its heart are two interesting integrated circuits that give us a little bit of insight into creating graphics at this level. First up is an RA8876 MIPI TFT controller which is a full graphics engine that produces a digital RGB output, followed by a CH7035B HDMI encoder that produces an HDMI output from the RGB. This combination of chips is particularly interesting one, because the RA8876 supports a variety of different interfaces that between them should be able to talk to most microcontrollers. In the Arduino world the only other HDMI options come via the use of an FPGA.

This is a project that seems to have been around for a couple of years, but which is still an active one. The classic Arduino shield form factor may now seem a little past its zenith, but as this board shows it’s still capable of being used for interesting new applications.

Thanks [th_in_gs] for the tip.