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Amazon Sidewalk: Should You Be Co-Opted Into A Private Neighbourhood LoRa Network?

30 November, by Jenny List[ —]

WiFi just isn’t very good at going through buildings. It’s fine for the main living areas of an average home, but once we venture towards the periphery of our domains it starts to become less reliable.  For connected devices outside the core of a home, this presents a problem, and it’s one Amazon hope to solve with their Sidewalk product.

It’s a low-bandwidth networking system that uses capability already built into some Echo and Ring devices, plus a portion of the owner’s broadband connection to the Internet.  The idea is to provide basic connectivity over longer distances to compatible devices even when the WiFi network is not available, but of most interest and concern is that it will also expose itself to devices owned by other people. If your Internet connection goes down, then your Ring devices will still provide a basic version of their functionality via a local low-bandwidth wide-area wireless network provided by the Amazon devices owned by your neighbours.

I Can See Your Amazon Ring From Here

It looks so harmless, doesn't it. A Ring doorbell once installed.
It looks so harmless, doesn’t it. Amin, CC BY-SA 4.0

The massive online retailer and IoT cloud provider would like to open up a portion of your home broadband connection via your home security devices over a wireless network to other similar devices owned by strangers. In the Amazon literature it is touted as providing all sorts of useful benefits to Ring and Echo owners, but it has obvious implications for both the privacy of your data should it be carried by other people’s devices, and for the security of your own network when devices you don’t own pass traffic over it. For the curious there’s a whitepaper offering more insights into the system, and aside from revealing that it uses 900 MHz FSK and LoRa as its RF layer there is a lot information on how it works. As you might expect they have addressed the privacy and security issues through encryption, minimising the data transmitted, and constantly changing identifiers. To read the Amazon document at face value is to enter a world in which some confidence can be gained in the product.

The question on the lips of skeptical readers will no doubt be this: what could possibly go wrong? We would expect that the devices themselves and the radio portion of the network will be investigated thoroughly by those who make it their business to do such things, and while there is always the chance that somebody could discover a flaw in them it’s more probable that weaknesses could be found in the applications that sit atop the system. It’s something that has plagued Amazon’s IoT offerings before, such as last year when their Neighbors app was found to sit atop a far more garrulous API than expected, leading to a little more neighbourly information being shared than they bargained for. If Amazon’s blurb is to be believed then this system is to be opened up for third-party IoT device and app developers, and with each one of those the possibility of holes waiting to be discovered increases. We’ll keep you posted as they emerge.

Products such as Amazon Echo and Ring are incredible showcases of 21st century technology. They’re the living embodiment of an automated Jetsons future, and we’d be lying if we said we didn’t want a little slice of that future. But as you all know, the version of that future peddled by them and their competitors is a deeply flawed one in which the consumers who buy the products are largely unaware of how much data is created from them. From a purely technical perspective the idea of home security products that automatically form a low bandwidth network for use in case of main network failure is an exceptionally cool one, but when coupled with the monster data slurp of the Amazon behemoth it assumes a slightly more worrying set of possibilities. Is it possible to be George Jetson without Mr. Spacely gazing over your shoulder?

Precision Optics Hack Chat with Jeroen Vleggaar of Huygens Optics

30 November, by Dan Maloney[ —]

Join us on Wednesday, December 2nd at noon Pacific for the Precision Optics Hack Chat with Jeroen Vleggaar!

We sometimes take for granted one of the foundational elements of our technological world: optics. There are high-quality lenses, mirrors, filters, and other precision optical components in just about everything these days, from the smartphones in our pockets to the cameras that loom over us from every streetlight and doorway. And even in those few devices that don’t incorporate any optical components directly, you can bet that the ability to refract, reflect, collimate, or otherwise manipulate light was key to creating the electronics inside it.

The ability to control light with precision is by no means a new development in our technological history, though. People have been creating high-quality optics for centuries, and the methods used to make optics these days would look very familiar to them. Precision optical surfaces can be constructed by almost anyone with simple hand tools and a good amount of time and patience, and those components can then be used to construct instruments that can explore the universe wither on the micro or macro scale.

Jeroen Vleggaar, know better as Huygens Optics on YouTube, will drop by the Hack Chat to talk about the world of precision optics. If you haven’t seen his videos, you’re missing out!

When not conducting optical experiments such as variable surface mirrors and precision spirit levels, or explaining the Double Slit Experiment, Jeroen consults on optical processes and designs. In this Hack Chat, we’ll talk about how precision optical surfaces are manufactured, what you can do to get started grinding your own lenses and mirrors, and learn a little about how these components are measured and used.

join-hack-chatOur Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, December 2 at 12:00 PM Pacific time. If time zones baffle you as much as us, we have a handy time zone converter.

Click that speech bubble to the right, and you’ll be taken directly to the Hack Chat group on Hackaday.io. You don’t have to wait until Wednesday; join whenever you want and you can see what the community is talking about.

Leaking Data Slowly By Switching Ethernet Speeds

30 November, by Lewin Day[ —]

Airgapping refers to running a machine or machines without connections to external networks. Literally, a gap of air exists between the machine and the outside world. These measures present a challenge to those wishing to exfiltrate data from such a machine, leading to some creative hacks. [Jacek] has recently been experimenting with leaking data via Ethernet adapters.

The hack builds on [Jacek]’s earlier work with the Raspberry Pi 4, in which the onboard adapter is rapidly switched between 10 and 100 Megabit modes to create a signal that can be picked up via radio up to 100 meters away. Since then, [Jacek] determined the Raspberry Pi 4, or at least his particular one, seems to be very leaky of RF energy from the Ethernet port. He decided to delve deeper by trying the same hack out on other hardware.

Using a pair of Dell laptops connected back to back with an Ethernet cable, the same speed-switching trick was employed. However, most hardware takes longer to switch speeds than the Pi 4; usually on the order of 2-5 seconds. This limited the signalling speed, but [Jacek] was able to set this up to exfiltrate data using QRSS, also known as very slow speed Morse code. The best result was picking up a signal from 10 meters away, although [Jacek] suspects this could be improved with better antenna hardware.

While slow data rates and the one-way nature of such communication limit the utility of such an attack, it nonetheless shows that securing a machine isn’t as simple as unplugging it from the network. We’ve done a feature on such hacks before for those interested in learning more. Video after the break.

Lithium: What Is It and Do We Have Enough?

30 November, by Matthew Carlson[ —]

Lithium (from Greek lithos or stone) is a silvery-white alkali metal that is the lightest solid element. Just one atomic step up from Helium, this magic metal seems to be in everything these days. In addition to forming the backbone of many kinds of batteries, it also is used in lubricants, mood-stabilizing drugs, and serves as an important additive in iron, steel, and aluminum production. Increasingly, the world is looking to store more and more power as phones, solar grids, and electric cars continue to rise in popularity, each equipped with lithium-based batteries. This translates to an ever-growing need for more lithium. So far production has struggled to keep pace with demand. This leads to the question, do we have enough lithium for everyone?

It takes around 138 lbs (63 kg) of 99.5% pure lithium to make a 70 kWh Tesla Model S battery pack. In 2016, OICA estimated that the world had 1.3 billion cars in use. If we replace every car with an electric version, we would need 179 billion pounds or 89.5 million tons (81 million tonnes) of lithium. That’s just the cars. That doesn’t include smartphones, laptops, home power systems, massive grid storage projects, and thousands of other products that use lithium batteries.

In 2019 the US Geological Survey estimated the world reserves of identified lithium was 17 million tonnes. Including the unidentified, the estimated total worldwide lithium was 62 million tonnes. While neither of these estimates is at that 89 million ton mark, why is there such a large gap between the identified and estimated total? And given the general rule of thumb that the lighter a nucleus is, the more abundant the element is, shouldn’t there be more lithium reserves? After all, the US Geological Survey estimates there are around 2.1 billion tonnes of identified copper and an additional 3.5 billion tonnes that have yet to be discovered. Why is there a factor of 100x separating these two elements?

What is Lithium and Where Does It Come From?

Lithium is geologically rare because it is unstable atomically due to it having the lowest binding energies per nucleon than any other stable nuclide. This is good for nuclear reactions (lithium was used as fuel in the first early nuclear reactions in 1932) but bad for finding it in nature. Further compounding its volatility, lithium is an alkali and will combust if allowed to come in contact with elements it reacts with, such as those found in the air. Pure lithium needs to be stored in oil to be transported safely.

This is a large 660 gram single, sharply terminated crystal of spodumene mined circa mid-1800s.
A 660 gram sharply terminated crystal of spodumene: Rob Lavinsky, iRocks.com

Given that it’s rare and reactive, the process of extraction differs from other metals. Currently, there are two ways that lithium can be extracted. The first way is from ionic compounds, such as pegmatitic minerals (made of quartz, feldspar, mica, and other crystals). For a long time, this was the world’s primary source of lithium. Much of Australia’s lithium production as of 2020 comes from spodumene, a pyroxene mineral that occurs in pegmatites and aplites.

In addition to being in minerals, lithium can be found in brines and ocean water because of its solubility as an ion. This means lithium saturated brines found in South America and Nevada can be dried using a solar evaporator, then once a good concentration is reached, the lithium carbonate and lithium hydroxide are precipitated by adding sodium carbonate (washing soda or soda ash) and calcium hydroxide (slaked lime or caustic lime). The brine extraction process usually takes 18 to 24 months.

However, the different processes are not equal in the lithium they produce. As mentioned earlier, battery manufacturers require 99.5% pure lithium and the remaining 0.5% is important. Brining tends to bring in iron or magnesium, impurities battery manufacturers try to avoid. Spodumene also has the advantage of purity as the deposit in Australia is an estimated 2.4% lithium. However, the sheer abundance of lithium in brines makes it very compelling even though the concentration is much lower (0.2-0.3%). An estimated 230 billion tons of lithium is dissolved in the oceans, but at 0.1-0.2ppm, it will be a while before extraction becomes economically viable. The difference between the identified reserved and the total estimated reserves can be mostly explained by brines. Brines are hard to estimate as they vary in concentration drastically and are often hidden in strange locations.

Uyuni Salt Flat by Leonardo Rossatti from Pexels

For example, most of the world’s lithium brines are concentrated in a region known as “The Lithium Triangle”, an intersection of Chile, Bolivia, and Argentina. This triangle is believed to contain over 75% of the existing known lithium. One such source of brine is the Salar de Uyuni salt flats in southwest Bolivia near the top of the Andes (almost 12000 ft or 3700 meters above sea level).

There’s a layer of salt on top that ranges from a few centimeters to several meters thick. Underneath the hard crust is a liquid brine with a relatively high concentration of lithium (0.3%). A hole drilled into the crust allows the brine to be pumped out and processed. As you can imagine, the high altitude complicates extraction and makes it more complex to transport the extracted lithium.

Battery Technologies

Why does lithium work so well as a battery? The myriad number of battery varieties using lithium seem endless. There is Li-MnO2, the most common consumer-grade battery chemistry, Li-FePO4, Li-CSVO, Li-CFx, Li-CuFeS, and Li-FeS2 are just some of the variants that are in common use today. Lewin Day wrote a beginner’s guide to lithium batteries that can help sort them out.

How a Lithium battery discharges
How a Li-ion battery discharges. Image by Sdk16420 CC-BY-SA

Every battery has three parts: an anode, a cathode, and an electrolyte. Most batteries today use a liquid electrolyte, which is made of lithium salts suspended in an organic solvent. Solid-state lithium batteries offer some promise but are still very much in development. They use solid lithium oxides as their electrolytes because being solid, they cannot leak, which is a safety issue for their liquid-based counterparts. The anode is often a material such as graphite or lithium titanate intercalated (a reversible layering) with lithium. Cathodes are often made from lithium nickel cobalt (LMO) or Lithium nickel manganese cobalt oxide (NMC).

The reversible reaction inside a lithium battery is quite similar across all lithium batteries. During discharge, an oxidation half-reaction occurs as the anode that forms negative electrons and positive lithium ions. The lithium ions head towards the cathode while the electrons move through the circuit towards the anode. They recombine there in a reduction half-reaction. Apply an electrical current and this reaction is reversed. Since both the cathode and the anode allow the lithium ions to intercalate within their structures, the lithium ions are said to “rock” back and forth between the two electrodes. Thanks to lithium’s relative instability and atomic structure, it is easy to form a lithium-ion and transport it through the battery.

This reaction does have its limits. Overvolting a battery (5.2 volts) leads to the synthesis of cobalt oxide, which causes damage to the electrodes. Letting the voltage potential drop too low results in the production of lithium oxide, which damages the battery irreversibly by reacting to the battery itself. You can learn a bit more about battery chemistry in this wonderful Bob Baddeley wrote last year.

Cathode/Cobalt issues

As I mentioned, the cathodes of batteries are often made with cobalt. Funny enough, cobalt is in someways rarer than lithium. Despite its rarity, the demand for cobalt has continued to skyrocket thanks to lithium-ion batteries. More than half of the world’s supply is in DR Congo, which is an infamously exploited area of the world. Child and slave labor are repeatedly reported in the mines and many companies have tried to find ethical sources of the material. Progress has been made to reduce the amount of cobalt required per battery and it has dropped from 1/3rd (NMC111) to 1/10th (NMC811) of the cathode. Many companies are trying to make batteries without cobalt entirely, for example, the Tesla Model 3 has an LFP cathode which is cobalt-free. Even with new technologies being put into production, we are still a long way from being cobalt-free and the majority of batteries today are still cobalt-based. We may face a cobalt shortage long before we face a lithium shortage.

Do We Have Enough For Everyone?

The short answer is probably. Dozens of different Universities and National Labs have come out with studies predicting one way or another. Lawrence Berkeley National Lab said in a 2011 study that we could build a billion 40 kWh lithium batteries with our existing reserves, however, they assumed only 10kg of lithium per battery (1/6th of a Tesla Model S). Even if we have enough raw materials, the process of converting it into a usable form needs to be considered.

Consumption has grown around 25% per year since 2012, outpacing the 4 to 5% yearly gain in production. At some point, something is going to have to change. Several have compared these market conditions to the oil industry. The demand for oil led to new methods for extraction and new technology that weren’t commercially viable before. We still have a large amount of research and development to do before extracting lithium from less concentrated sources such as the ocean becomes more economically viable. That said, there are a few things we could do that might ease the bumps along the way.

Recycling Lithium

Recycling lithium has been a dream of researchers and engineers alike. A few hurdles stand in the way of that dream, namely designing for recycling and cost-effectiveness. Unlike lead-acid batteries, which are designed with recycling in mind and achieve around a 98% recycling rate by mass, lithium-ion batteries are often focused on fitting the size and shape of the product they are in. Recycling also requires labeling to tell what chemistry the battery is, which lithium-ion batteries often do not. Unlike lead-acid, lithium batteries have anodes and cathodes of similar density, which makes them hard to separate out for recycling. This requires complex chemical or magnetic separation steps that vary according to the battery chemistry.

That said, universities are working to improve the process. While their results are incredibly promising, there’s still the problem that recycling is not economically viable yet. Just buying the raw materials and making new batteries is cheaper than recycling old ones.

New Battery Technologies

Every few years or so, some new battery technology gets heralded as our potential savior. It seems that the promises of new and better batteries being just around the corner are held up each year anew. We’ve covered the current contenders as well as some promising upstarts such as lithium-sulfur and lithium-ceramic. Each promises different things like higher energy density, faster recharge, or being more environmentally friendly. While the general consensus is that we’ll believe the battery breakthrough hype when we see it in a consumer product, we still must give credit to all the researchers and engineers over the last few decades creating the steady stream of improvements to the lithium-ion battery.

So next time you look at the small lithium battery in your project or the large bank of 18650 cells, take a moment to appreciate where they came from and perhaps even allow yourself to wonder what will come next.

Urban Explorers Reveal A Treasure Trove Of Soviet Computing Power

30 November, by Jenny List[ —]

It’s probably a dream most of us share, to stumble upon a dusty hall full of fascinating abandoned tech frozen in time as though its operators walked away one day and simply never returned. It’s something documented by some Russian urban explorers who found an unremarkable office building with one of its floors frozen sometime around the transition from Soviet Union to Russian Federation. In it they found their abandoned tech, in the form of a cross-section of Soviet-era computers form the 1970s onwards.

As you might expect, in a manner it mirrors the development of civilian computing on the capitalist side of the Iron Curtain over a similar period, starting with minicomputers the size of several large refrigerators and ending with desktop microcomputers. The minis seem to all be Soviet clones of contemporary DEC machines. with some parts of them even looking vaguely familiar. The oldest is a Saratov-2, a PDP/8 clone which we’re told is rare enough for no examples to have been believed to have survived until this discovery. We then see a succession of PDP/11 clones each of which becomes ever smaller with advancements in semiconductor integration, starting with the fridge-sized units and eventually ending up with desktop versions that resemble 1980s PCs.

While mass-market Western desktop machines followed the path of adopting newer architectures such as the Z80 or the 8086 the Soviets instead took their minicomputer technology to that level. It would be interesting to speculate how these machines might further have developed over the 1990s had history been different. Meanwhile we all have a tangible legacy of Soviet PDP/11 microcomputers in the form of Tetris, which was first written on an Elektronika 60.

We know that among our readers there is likely to be a few who encountered similar machines in their heyday, and we hope they’ll share their recollections in the comments. Meanwhile we hope that somehow this collection can be preserved one day. If your thirst for dusty mincomputers knows no bounds, read about the collectors who bought an IBM machine on eBay and got more than they bargained for.

Via Hacker News.

DVK-1 desktop computer, «Переславская неделя» / В. С. Спиридонов  CC-BY-SA 3.0.

Pushing The FPGA Video Player Further

30 November, by Matthew Carlson[ —]

A fact universally known among the Hackaday community is that projects are never truly done. You can always spin another board release to fix a silkscreen mistake, get that extra little boost of performance, or finally spend the time to track down that weird transient bug. Or in [ultraembedded’s] case, take a custom FPGA player from 800 x 600 to 1280 x 720. The hardware used is a Digilent Arty A7 and PMOD boards for I2S2, VGA, and MicroSD. We previously covered this project back when it was first getting started.

Getting from 800 x 600 to 1280 x 720 — 31% more pixels — required implementing a higher performance JPEG decoder that can read in the MPJEG frames, pushing out a pixel every 2.1 clock cycles. The improvements also include a few convenience features such as an IR remote. The number of submodules inside the system is just incredible, with most of them being implemented or tweaked by [ultraembedded] himself.

For the FPGA Verilog, there’s the SD/MMC interface, the JPEG decoder, the audio controller, the DVI framebuffer, a peripheral core, and a custom RISC-V CPU. For the firmware loaded off the SD card, it uses a custom RTOS running an MP3 decoder, a FAT32 interface, an IR decoder, and a UI based on LVGL.

We think this project represents a wonderful culmination of all the different IP cores that [ultraembedded] has produced over the years. All the code for the FPGA media player is available on GitHub.

I think I’ve built myself an HD (720p50) video player out of an #FPGA, #RISCV, #MJPEG and 27,000 lines of Verilog! Going from 800×600 -> 1280×720 just worked with 10 more MHz! I actually plan to sit down and watch a movie on this one evening! https://t.co/4G1ZiN2ipY

– ultraembedded (@ultraembedded) November 21, 2020

Mouse-Controlled Mouse Controller Is Silly, But Could Be Useful

30 November, by Lewin Day[ —]

Useless machines are generally built as a fun pastime, as they do nothing of value by their very definition. The most popular type generally involves a self-cancelling switch. However, there’s plenty of other useless machines to build, and we think [Jeffery’s] build is particularly creative.

The build consists of an XY gantry that moves a standard computer mouse. To control the gantry, a Raspberry Pi feeds the system G-Code relative to the motion of a second mouse plugged into the single-board computer. It’s pretty standard fare overall, with the Pi sending commands to an Arduino that runs the various stepper motors via a CNC controller shield.

Yes, it’s a mouse that moves a mouse – and on the surface, this appears to be a very useless machine. However, we could imagine it being useful for remote control of a very old system that uses a non-standard mouse that is otherwise difficult to emulate. Additionally, it wouldn’t take much extra work to turn the XY gantry into a competent pen-plotter – of which we’ve seen many. Video after the break.

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