Feeling The Heat: Railway Defect Detection

On the technology spectrum, railroads would certainly seem to skew toward the brutally simplistic side of things. A couple of strips of steel, some wooden ties and gravel ballast to keep everything in place, some rolling stock with flanged wheels on fixed axles, and you’ve got the basics that have been moving freight and passengers since at least the 18th century.

But that basic simplicity belies the true complexity of a railway, where even just keeping the trains on the track can be a daunting task. The forces that a fully loaded train can exert on not only the tracks but on itself are hard to get your head around, and the potential for disaster is often only a failed component away. This became painfully evident with the recent Norfolk Southern derailment in East Palestine, Ohio, which resulted in a hazardous materials incident the likes of which no community is ready to deal with.

Given the forces involved, keeping trains on the straight and narrow is no mean feat, and railway designers have come up with a web of sensors and systems to help them with the task of keeping an eye on what’s going on with the rolling stock of a train. Let’s take a look at some of the interesting engineering behind these wayside defect detectors.

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Hams Watch For Meteors

After passing an exam and obtaining a license, an amateur radio operator will typically pick up a VHF ratio and start talking to other hams in their local community. From there a whole array of paths open up, and some will focus on interesting ways of bouncing signals around the atmosphere. There are all kinds of ways of propagating radio waves and bouncing them off of various reflective objects, such as the Moon, various layers of the ionosphere, or even the auroras, but none are quite as fleeting as bouncing a signal off of a meteor that’s just burned up in the atmosphere.

While they aren’t specifically focused on communicating via meteor bounce, The UK Meteor Beacon Project hopes to leverage amateur radio operators and amateur radio astronomers to research more about meteors as they interact with the atmosphere. A large radio beacon, which has already been placed into service, broadcasts a circularly-polarized signal in the six-meter band which is easily reflected back to Earth off of meteors. Specialized receivers can pick up these signals, and are coordinated among a network of other receivers which stream the data they recover over the internet back to a central server.

With this information, the project can determine where the meteor came from, some of the properties of the meteors, and compute their trajectories by listening for the radio echoes the meteors produce. While this is still in the beginning phases and information is relatively scarce, the receivers seem to be able to be built around RTL-SDR modules that we have seen be useful across a wide variety of radio projects for an absolute minimum of cost.

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It’s Difficult To Read An Audiophile Guide As An Analogue Engineer

Sitting on a train leaving the Hackaday Berlin conference, and Hacker News pops up Julian Shapiro with a guide to HiFi. What Hackaday scribe wouldn’t give it a click, to while away the endless kilometres of North European Plain!

It’s very easy as an analogue electronic engineer, to become frustrated while reading audiophile tracts, after all they have a tendency to blur superficial engineering talk with pseudoscience. There’s a rich vein of parody to be found in them, but nevertheless it’s interesting to read them because just sometimes the writer gets it and doesn’t descend into the world of make-believe. Continue reading “It’s Difficult To Read An Audiophile Guide As An Analogue Engineer”

An Old Netbook Spills Its Secrets

For a brief moment in the late ’00s, netbooks dominated the low-cost mobile computing market. These were small, low-cost, low-power laptops, some tiny enough to only have a seven-inch display, and usually with extremely limiting hardware even for the time. There aren’t very many reasons to own a machine of this era today, since even the cheapest of tablets or Chromebooks are typically far more capable than the Atom-based devices from over a decade ago. There is one set of these netbooks from that time with a secret up its sleeve, though: Phoenix Hyperspace.

Hyperspace was envisioned as a way for these slow, low-power computers to instantly boot or switch between operating systems. [cathoderaydude] wanted to figure out what made this piece of software tick, so he grabbed one of the only netbooks that it was ever installed on, a Samsung N210. The machine has both Windows 7 and a custom Linux distribution installed on it, and with Hyperspace it’s possible to switch almost seamlessly between them in about six seconds; effectively instantly for the time. Continue reading “An Old Netbook Spills Its Secrets”

Long-Distance Gaming Over Packet Radio

The amateur radio community often gets stereotyped as a hobby with a minimum age requirement around 70, gatekeeping airwaves from those with less experience or simply ignoring unfamiliar beginners. While there is a small amount of truth to this on some local repeaters or specific frequencies, the spectrum is big enough to easily ignore those types and explore the hobby without worry (provided you are properly licensed). One of the best examples of this we’ve seen recently of esoteric radio use is this method of using packet radio to play a game of Colossal Cave Adventure.

Packet radio is a method by which digital information can be sent out over the air to nodes, which are programmed to receive these transmissions and act on them. Typically this involves something like email or SMS messaging, so playing a text-based game over the air is not too much different than its intended use. For this build, [GlassTTY] aka [G6AML] is using a Kenwood TH-D72 which receives the packets from a Mac computer. It broadcasts these packets to his node, which receives these packets and sends them to a PDP-11 running the game. Information is then sent back to the Kenwood and attached Mac in much the same way as a standard Internet connection.

The unique features of packet radio make it both an interesting and useful niche within the ham radio community, allowing for all kinds of uses where data transmission might otherwise be infeasible or impossible. A common use case is APRS, which is often used on VHF bands to send weather and position information out, but there are plenty of other uses for it as well.

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Hackaday Berlin Was Bonkers

In celebration of the tenth running of the Hackaday Prize, we had a fantastic weekend event in Berlin. This was a great opportunity for all of the European Hackaday community to get together for a few days of great talks, fun show-and-tells, and above all good old fashioned sitting together and brainstorming. Of course there was the badge, and the location – a gigantic hackerspace in Berlin called MotionLab – even had a monstrous laser-eye octopus suspended from a gantry overhead. Everyone who came brought something to share or to show. You couldn’t ask for more.

Unfortunately, we weren’t able to record the talks, so we’ll run down the highlights for you here. [Jenny List] is writing up a bunch of the badge hacks as we speak, so we’ll skip that for now. For the full experience, you just had to be there, but we’ll share with you what pictures we got. Enjoy!

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A Survey Of Long-Term Waterproofing Options

When it comes to placing a project underwater, the easy way out is to just stick it in some sort of waterproof container, cover it with hot glue, and call it a day. But when you need to keep water out for several years, things get significantly harder. Luckily, [Patricia Beddows] and [Edward Mallon] from the Cave Pearl Project have written up their years of experience waterproofing data loggers for long-term deployment, making the process easier for the rest of us.

Cleaning cheap eBay boards in alcohol.

It starts with the actual board itself. Many SMD boards have at least some flux left over from the assembly process, which the duo notes has a tendency to pull water in under components. So the first step is to clean them thoroughly with an ultrasonic cleaner or toothbrush, though some parts such as RTCs, MEMs, or pressure sensors need to be handled with significant care.

Actual waterproofing starts with a coating like 422-B or nail polish which each have pros and cons. [Patricia] and [Edward] often apply coatings to PCBs even if they plan to otherwise seal it as it offers a final line of defense. The cut edges of PCBs need to be protected so that water can’t seep between layers, though care needs to be made for connectors like SD cards.

Encapsulation with a variety of materials such as hot glue, heat shrink tubing, superglue and baking soda, silicone rubber, liquid epoxy, paste epoxy (like J-B Weld), or even wax are all commented on. The biggest problem is that a material can be waterproof but not water vapor proof. This means that condensation can build up inside a housing. Temperature swings also can play havoc with sealings, causing gaps to appear as it expands or contracts.

Overall, it’s an incredible guide with helpful tips and tricks for anyone logging data underwater for science or even just trying to waterproof their favorite watch.

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