Borehole Camera Rig Makes Life Easier In Mining

Much of mining involves digging and drilling holes in the ground. Often, these holes need inspecting, but [Dean Harty] found that existing borehole inspection solutions weren’t up to snuff. Resolution was poor, and often live-view devices made recording footage a pain. Instead, he set about the development of the Sneaky Peaky, going through several revisions in the process.

The first revision was nothing more than a GoPro strapped to a small penny board, paired with a bright flashlight. The 4K resolution of the GoPro provided useful footage, and the assembly could be lowered into boreholes on a rope and retrieved easily. Rugged and water resistant, the gear worked well, and was remarkably cheap compared to more obscure mining industry hardware.

An early version of the Sneaky Peaky

Later revisions ditched the skateboard, replacing it with a pipe-style housing instead. Key to the design was that the device could readily be destroyed and flushed out of a borehole with an air blast in the event it got stuck.

Eventually, mining outfit Metrologi got involved, having worked with [Dean] on several borehole backfill operations. A 3D-printed chassis was developed to hold an action camera and twin torches, held together with plastic zip ties. These are attached to the pull rope, and if the camera becomes jammed, a sharp pull will snap the ties and cause the device to fall apart. Steel cable ties are then used to create flexible guides to center the assembly in a variety of pipe diameters.

It’s a great example of people on the ground hacking together the tools they need, combined with iterative design to integrate improvements over time. We don’t talk about boreholes much around here, but they can be musical if properly employed, as it turns out. If you’ve got your own great mining hacks, however, do drop us a line!

Dial A For Arduino

A lot of phrases surrounding phones don’t make sense anymore. With a modern cellphone, you don’t really “hang up” and there’s certainly no “dial” to be had. However, with [jakeofalltrades’] project, you can read an old-fashioned phone dial using an Arduino.

The idea behind a phone dial is actually pretty simple. When you pull the dial back to the stop using one of the numbered holes and release it, it causes a switch to open and close the same number of times as the hole you selected. That is, if you pull back the 5 hole, you should get 5 switch closures. The duration of each switch event and the time between switch events is a function of the speed the dial moves because of its internal spring. The zero hole actually produces ten pulses.

There are standards for how precise the timing has to be, but — honestly — it’s pretty loose since these were not made to be read by precise microcontroller timers. In the United States, for example, the dial was supposed to produce between 9.5 and 10.5 pulses per second, but the equipment on the other end would tolerate anything from 8 to 11.

Even if you don’t want a rotary dial in your next project, the code has some good examples of using ATmega328 timers that you might find useful in another context. However, a dial would add a nice retro touch to any numeric input you might happen to need.

If you need project inspiration, how about a volume control? Or, why not a numeric keypad?

Single Event Upsets: High Energy Particles From Outer Space Flipping Bits

Our world is constantly bombarded by high-energy particles from various sources, and if they hit in just the right spot on the sensitive electronics our modern world is built on, they can start flipping bits. Known as Single Event Upsets (SEU), their effect can range from unnoticeable to catastrophic, and [Veritasium] explores this phenomenon in the video after the break.

The existence of radiation has been known since the late 1800s, but the effect of low-level radiation on electronics was only recognized in the 1970s when trace amounts of radioactive material in the ceramic packaging of Intel DRAM chips started causing errors. The most energetic particles come from outer space and are known as cosmic rays. They originate from supernovas and black holes, and on earth they have been linked to an impossibly fast Super Mario 64 speedrun and a counting error in a Belgian election. It’s also possible to see their path using a cloud chamber you can build yourself. There are even research projects that use the camera sensors of smartphones as distributed cosmic ray detectors.

Earth’s magnetic field acts as a protective barrier against the majority of these cosmic rays, and there is a measurable increase in radiation as you gain altitude and enter space. In space, serious steps need to be taken to protect spacecraft, and it’s for this reason that the Perseverance rover that landed on Mars this year uses a 20-year-old main computer, the PowerPC RAD750. It has a proven track record of radiation resistance and has been used on more than a dozen spacecraft. Astronauts experience cosmic radiation in the form of flashes of light when they close their eyes and protecting their DNA from damaging effects is a serious concern for NASA.

It’s impossible to know the true impact of cosmic radiation on our world and even our history. Who knows, one of those impossible-to-replicate software bugs or the inspiration for your latest project might have originated in another galaxy. Continue reading “Single Event Upsets: High Energy Particles From Outer Space Flipping Bits”

Drive High-Impedance Headphones With This Stylish USB DAC

For anyone with an interest in building audio projects, it’s likely that an early project will be a headphone amplifier. They’re relatively easy to build from transistors, ICs, or tubes, and it’s possible to build one to a decent quality without being an electronic engineering genius. It’s not often though that we see one as miniaturized as [daumemo]’s USB-C DAC and headphone amplifier combo, that fits within a slightly elongated 3.5 mm jack cover as part of a small USB-to-headphone cable.

The DAC is an off-the-shelf board featuring an ALC4042 IC, it has a line-level output and a handy place to tap off a 5 volt line for the amplifier. This final part is a tiny PCB with two chips, a TPS65135 that produces clean +5 and -5 volt rails, and an INA1620 which is a high-quality audio amplifier set up for 2x gain. All this has been designed onto a very small PCB, which sits inside a 3D-printed housing along with the 3.5 mm earphone socket. The result is a very neat unit far better able do drive high-impedance headphones than the output from an unmodified DAC, but still looking as svelte as any commercial product. We like it.

This may be one of the most compact USB-to-headphone amplifiers we’ve seen, but it’s by no means the first.

Making Coffee With Hydrogen

Something of a Holy Grail among engineers with an interest in a low-carbon future is the idea of replacing fossil fuel gasses with hydrogen. There are various schemes, but they all suffer from the problem that hydrogen is difficult stuff to store or transport. It’s not easily liquefied, and the tiny size of its molecule means that many containment materials that are fine for methane simply won’t hold on to it.

[Isographer] has an idea: to transport the energy not as hydrogen but as metallic aluminium, and generate hydrogen by reaction with aqueous sodium hydroxide. He’s demonstrated it by generating enough hydrogen to make a cup of coffee, as you can see in the video below the break.

It’s obviously very successful, but how does it stack up from a green perspective? The feedstocks are aluminium and sodium hydroxide, and aside from the hydrogen it produces sodium aluminate. Aluminium is produced by electrolysis of molten bauxite and uses vast amounts of energy to produce, but since it is often most economic to do so using hydroelectric power then it can be a zero-carbon store of energy. Sodium hydroxide is also produced by an electrolytic process, this time using brine as the feedstock, so it also has the potential to be produced with low-carbon electricity. Meanwhile the sodium aluminate solution is a cisutic base, but one that readily degrades to inert aluminium oxide and hydroxide in the environment. So while it can’t be guaranteed that the feedstock he’s using is low-carbon, it’s certainly a possibility.

So given scrap aluminium and an assortment of jars it’s possible to make a cup of hot coffee. It’s pretty obvious that this technology won’t be used in the home in this way, but does that make it useless? It’s not difficult to imagine energy being transported over distances as heavy-but-harmless aluminium metal, and we’re already seeing a different chemistry with the same goal being used to power vehicles.

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Hackers And China

The open source world and Chinese manufacturing have a long relationship. Some fifteen years ago, the big topic was how companies could open-source their hardware designs and not get driven bankrupt by competition from overseas. Companies like Sparkfun, Adafruit, Arduino, Maple Labs, Pololu, and many more demonstrated that this wasn’t impossible after all.

Maybe ten years ago, Chinese firms started picking up interesting hacker projects and producing them. This gave us hits like the AVR transistor tester and the NanoVNA. In the last few years, we’ve seen open-source hardware and software projects that have deliberately targeted Chinese manufacturers, and won. We do the design and coding, they do the manufacturing, sales, and distribution.

But this is something else: the Bangle.js watch takes an essentially mediocre Chinese smartwatch and reflashes the firmware, and sells them as open-source smartwatches to the general public. These pre-hacked watches are being sold on Kickstarter, and although the works stands on the shoulders of previous hacker’s reverse engineering work on the non-open watch hardware, it’s being sold by the prime mover behind the Espruino JavaScript-on-embedded language, which it runs on.

We have a cheap commodity smartwatch, being sold with frankly mediocre firmware, taken over by hackers, re-flashed, re-branded, and sold by the hackers on Kickstarter. As a result of it being (forcibly) opened, there’s a decently sized app store of contributed open-source applications that’ll run on the platform, making it significantly more useful and hacker friendly than it was before.

Will this boost sales? Will China notice the hackers’ work? Will this, and similar projects, end up in yet another new hacker/China relationship? We’re watching.

When Benchies Fly

Most of us have printed a few benchies to test our 3D printers. The intrepid little boat has a variety of features that tax different parts of the printing process. However, the guys at [FliteTest] had a different idea. They set out in a competition to build a giant flying benchie. They aren’t quite done, but they did make some interesting progress, as you can see in the video below.

In all fairness, the benchies are not, themselves, 3D printed. Foamboard, however, is a bit more practical.¬† Inevitably, you can’t help but think of a flying boat when you see the results.

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