Year: 2020

Basics Of Remote Cellular Access – Choosing A Modem

December 18, 2020 by 23 Comments

These days, we’re blessed with cellular data networks that span great swathes of the Earth. By and large, they’re used to watch TV shows and argue with strangers online. However, they’re also a great tool to use to interact with hardware in remote locations, particularly mobile ones where a wired connection is impractical.

In this series, we’re taking a look at tips and tricks for doing remote cellular admin the right way. First things first, you’ll need a data connection – so let’s look at choosing a modem.

Options Abound

When shopping around for cellular data modems, it can be difficult to wade through the variety of options out there and find something fit for purpose. Modems in this space are often marketed for very specific use cases; at the consumer level, many are designed to be a no-fuss home broadband solution, while in the commercial space, they’re aimed primarily to provide free WiFi for restaurants and cafes. For use in remote admin, the presence of certain features can be critical, so it pays to do your research before spending your hard earned money. We’ve laid out some of the common options below.

Consumer Models

The Sierra Aircard 320U is ancient now, with limited frequency bands available. Its flimsy flexible connector is also a drawback. However, its ease of configuration with Linux systems makes it a dream to use in remote access situations. Unlike many others, it acts as a Direct IP connection, not appearing as a separate router.

Many telecommunications providers around the world sell cheap USB dongles for connecting to the Internet, with these first becoming popular with the rise of 3G. They’re somewhat less common now in the 5G era, with the market shifting more towards WiFi-enabled devices that share internet among several users. These devices can often be had for under $50, and used on prepaid and contract data plans.

These devices are often the first stop for the budding enthusiast building a project that needs remote admin over the cellular network. However, they come with certain caveats that can make them less attractive for this use. Aimed at home users, they are often heavily locked down with firmware that provides minimal configuration options. They’re generally unable to be set up for port forwarding, even if you can convince your telco to give you a real IP instead of carrier-grade NAT. Worse, many appear to the host computer as a router themselves, adding another layer of NAT that can further complicate things. Perhaps most frustratingly, with these telco-delivered modems, the model number printed on the box is often not a great guide as to what you’re getting.

A perfect example is the Huawei E8327. This comes in a huge number of sub-models, with various versions of the modem operating in different routing modes, on different bands, and some even omitting major features like external antenna connectors.  Often, it’s impossible to know exactly what features the device has until you open the box and strip the cover off, at which point you’re unable to return the device for your money back.

All is not lost, however. The use of VPNs can help get around NAT issues, and for the more adventurous, some models even have custom firmware available on the deeper, darker forums on the web. For the truly cash strapped, they’re a viable option for those willing to deal with the inevitable headaches. There are generally some modems that stand out over others in this space for configurability and ease of use. This writer has had great success with a now-aging Sierra Aircard 320U, while others have found luck with the Huawei E3372-607. As per earlier warnings though, you don’t want to accidentally end up with an E3372-608 – thar be dragons.

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Hackaday Podcast 098: China’s Moon Rocks, Antikythera Revelations, Creality Vs Octoprint, And RC Starship

December 18, 2020 by No comments

Hackaday editors Elliot Williams and Tom Nardi contemplate a few of the most interesting stories that made their way through the tubes this week. We’ll learn how old VHS tapes can be turned into a unique filament for your 3D printer, and realize that the best way to learn about a 2,000 year old computer is to break out the hand drill and make one yourself. Hobby grade RC gear and a some foam board stand in for SpaceX’s next-generation Mars spacecraft, and a manufacturer of cheap 3D printers attempts to undercut a popular open source project with hilarious results. Finally, we’ll take a close look at some hidden aluminum boogers and discuss how China’s history making trek to the Moon might be a prelude to the country making a giant leap of their own.

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)

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Edge-Mounted LEDs Make This Spherical POV Look Fantastic

December 18, 2020 by 19 Comments

For as many of them as we’ve seen, we still love a good persistence of vision display project. There’s something fascinating about the combination of movement and light creating the illusion of solid surfaces, and there’s always fun to be had in electromechanical aspects of a POV build. This high-resolution spherical POV display pushes all those buttons, and more.

Called “Flicker” for obvious reasons by its creator [Dan Foisy], this POV display started with a pretty clear set of goals in terms of resolution and image quality, plus the need to support animated images, all in a spherical form factor. These goals dictated the final form of the display — a PCB disc spinning vertically. The shaft has the usual slip rings for power distribution and encoders for position feedback. The PCB, though, is where the interesting stuff is.

[Dan] chose to use an FPGA to slice and dice the images, which are fed from a Raspberry Pi’s HDMI port, to the LED drivers. And the LEDs themselves are pretty slick — he found parts with 1.6 mm lead spacing, making them a perfect fit for mounting on the rim of the PCB rather than on either side. A KiCAD script automated the process of laying out the 256 LEDs and their supporting components as evenly as possible, to avoid imbalance issues.

The video below shows Flicker in action — there are a few problem pixels, but on the whole, the display is pretty stunning. We’ve seen a few other spherical POV displays before, but none that look as good as this one does.

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This Week In Security: SolarWinds And FireEye, WordPress DDoS, And Enhance!

December 18, 2020 by 11 Comments

The big story this week is Solarwinds. This IT management company supplies network monitoring and other security equipment, and it seems that malicious code was included in a product update as early as last spring. Their equipment is present in a multitude of high-profile networks, like Fireeye, many branches of the US government, and pretty much any other large company you can think of. To say that this supply chain attack is a big deal is an understatement. The blame has initially been placed on APT42, AKA, the Russian hacking pros.

The attack hasn’t been without some positive effects, as Fireeye has released some of their internal tooling as open source as a result. Microsoft has led the official response to the attack, managing to win control of the C&C domain in court, and black-holing it.

The last wrinkle to this story is the interesting timing of the sale of some Solarwinds stock by a pair of investment firms. If those firms were aware of the breech, and sold their shares before the news was made public, this would be a classic case of illegal insider trading. Continue reading “This Week In Security: SolarWinds And FireEye, WordPress DDoS, And Enhance!” →

Building A Smash Bros. Controller With Keyswitches

December 18, 2020 by 5 Comments

When it comes to competitive fighting games, having the right controller in your hands can make the difference between victory and defeat. Many tournaments have strict rules around controllers for this very reason. [Akaki Kuumeri] has recently put together a custom controller, aimed at maximising performance in Super Smash Brothers: Ultimate on the Nintendo Switch. (Video, embedded below.)

The build is assembled in an attractive 3D-printed body, made to be reminiscent of the original Nintendo Entertainment System controller. Inside, a cheap third-party Gamecube controller is used to interface with the console. Mechanical keyboard switches are used to replace the buttons and even the analog sticks, with a special modifier key that enables walking and running across the stage. This is pulled off with a handful of resistors emulating the intermediate position of the analog sticks, and makes pulling off advanced combos easier.

It’s a fun build, and we can imagine the precise digital key inputs having some benefits over analog controls. It also pays to note that such a build wouldn’t be as easy without the ready supply of mechanical key switches thanks to the custom keyboard subculture. We’ve seen these satisfying switches cropping up in many controller builds in recent times.

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Stacked Material Makes Kitchen Temperature Superconductors

December 18, 2020 by 35 Comments

Belgian, Italian, and Australian researchers are proposing that by stacking semiconductor sheets, they should be able to observe superconducting behavior at what is known as “kitchen temperature” or temperatures you could get in a household freezer. That’s not quite as good as room temperature, but it isn’t bad, either. The paper is a bit technical but there is a very accessible write-up at Sci-Tech Daily that gives a good explanation.

Superconductors show no loss but currently require very cold temperatures outside of a few special cases. The new material exploits the idea that an electron and a hole in a semiconducting material will have a strong attraction to each other and will form a pair known as an exciton. Excitons move in a superfluid state which should exhibit superconductivity regardless of the temperature. However, the attraction is so strong that in conventional materials, the excitons only exist for the briefest blip of time before they cancel each other out.

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900-Degree Racing Wheel Helps You Nail The Apex

December 17, 2020 by 21 Comments

There are many racing wheels on the market for the budding sim enthusiast. Unfortunately, lower end models tend to have a limited range of motion and ship with cheap plastic wheels that don’t feel good in the hand. As always, if what’s on the shelf doesn’t meet your needs, you can always build your own. [ilge]’s DIY racing wheel build is a great example of how to go about it. 

It’s a no-frills build, with an Arduino Leonardo doing the USB Human Interface Device duties in this case. It reads a standard 10K potentiometer via an analog input to determine wheel position. To enable a realistic 900 degrees of motion, unlike the standard 270 degree rotation of the potentiometer, [ilge] uses 3D printed gears of 15 and 54 degrees respectively. This also has the benefit of allowing the wheel to be mounted to a stout bearing for smooth motion. The steering wheel itself is a high quality drift wheel from MOMO, and the benefit of building your own setup is that you can choose whatever wheel you like to taste.

It’s a simple build both mechanically and electronically speaking, but one that serves as a great entry into building a DIY sim for the beginner. We’d love to see further upgrades towards force feedback, or even shift paddles added on the back. Those looking to go all out can even consider building a motion platform. Video after the break.

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