In planetary exploration circles, Mars has quite a bad reputation. The Red Planet has a habit of eating spacecraft sent there to explore it, to the degree that nearly half of the missions we’ve thrown at it have failed in one way or another. The “Mars Curse” manifests itself most spectacularly when landers fail to negotiate the terminal descent and new billion-dollar craters appear on the Martian regolith, while some missions meet their doom en route to the planet, and an unlucky few have even blown up on the launchpad.
But the latest example of the Mars Curse, the recent cancellation of the second half of the ExoMars mission, represents a new and depressing failure mode: war — specifically the Russian invasion of Ukraine. The international outrage over the aggression resulted in economic sanctions and diplomatic isolation of Russia, which retaliated by ending its partnership with the European Space Agency (ESA), depriving the mission of its launch vehicle and dooming the mission that would have landed the rover Rosalind Franklin on Oxia Planum near the Martian Equator in 2023.
While there’s still a chance that administrators and diplomats will work things out, chances are slim that it will be in time for the narrow launch window that the mission was shooting for in September of 2022. That means the Rosalind Franklin, along with all the other flight hardware that was nearly ready to launch, will have to be put in storage at least until the next launch window opens in 2024. That begs the question: how does one put a complex spacecraft into storage? And could such mothballing have unintended consequences for the mission when it eventually does fly?
With the news here in Europe full of the effect of the war in Ukraine on gas supplies and consequently, prices, there it was on the radio news: a unit of measurement so uniquely British that nobody uses it in the real world and nobody even has a clue what it really means. We’re speaking of the Therm, one of those words from our grandparents’ era of coal gas powered Belling cookers and Geyser water heaters hanging over the bath, which has somehow hung on in the popular imagination as a mysterious unit of domestic gas referred to only in the mass market news media. What on earth is a therm, and why are we still hearing it on the news in the UK?
You can’t Buy A Therm
Asking the internet what a therm is reveals the answer, it’s 100,000 BTU. What’s a BTU? A British Thermal Unit, another anachronistic measurement five decades after the UK went metric, it’s the amount of energy required to raise a pound of water by a degree Fahrenheit. Which in turn is about 1,054 joules, in today’s measurements. So a therm is thus a unit of energy, can we take a look at our gas meters and see how many of them we’ve used this winter? Not so fast, because gas isn’t sold by the therm. Older gas meters had cubic feet on them, and we’re guessing that now they’re calibrated in cubic meters. We can’t even buy a therm of gas, so why on earth are the British media still using it? Continue reading “Just What On Earth Is A Therm?”→
Although every electrical grid begins with the production of electricity, there are times when storing this power in some form instead of using it immediately is highly convenient. Today’s battery-powered gadgets are an obvious example of such time-shifting, but energy storage plays a major role on the grid itself, too, whether in electrochemical, mechanical or in some other form.
Utility-level energy storage is essential for not only stabilizing the grid, but also to time-shift excess energy and provide a way to deal with sudden spikes in demand (peak-shaving) plus demand drops by absorbing the excess energy. The health of the grid can essentially be regarded as a function of its alternating current (AC) frequency, with strong deviations potentially leading to a collapse of the grid.
Naturally, such energy storage is not free, and the benefits of adding it to the grid have to be considered against the expense, as well as potential alternatives. With the rapid increase of highly volatile electrical generators on the grid in the form of non-dispatchable variable renewable energy, e.g. wind turbines and PV solar, there has been a push to store more excess power rather than curtailing it, in addition to using energy storage for general grid health.
RS485 is a communication standard that should be part of the advanced hardware hacker’s arsenal; it’s not commonly encountered, but powerful exactly when you need it. It’s a physical layer interface for wired communications that uses a single differential pair for noise immunity, has good long-distance properties, and allows many connections to a single bus. Because of that, you will encounter it in security systems and even cameras, wired sensor networks, DMX512 lighting and all sorts of industrial electronics. For our hobbyist goals, you can absolutely use RS485 to build your home (or room) automation system, or a relatively large robot – without all those worries that wireless brings.
The name might remind you of RS232, and that’s because both RS232 and RS485 are standards that come from EIA (Electronics Industries Alliance). It also might remind you of RS422, if you’ve ever seen this name mentioned online – RS422 and RS485 are closely intertwined, sharing most of the physical layer, and I’ll show how exactly they relate. Continue reading “Hacker Dictionary: RS-485 Will Go The Distance”→
As a standard feature of the Linux kernel, device tree overlays (DTOs) allow for easy enabling and configuration of features and drivers, such as those contained within the standard firmware of a Raspberry Pi system. Using these DTOs it’s trivial to set up features like as a soft power-off button, triggering an external power supply and enable drivers for everything from an external real-time clock (RTC) to various displays, sensors and audio devices, all without modifying the operating system or using custom scripts.
It’s also possible to add your own DTOs to create a custom overlay that combines multiple DTO commands into a single one, or create a custom device tree binary (DTB) for the target hardware. Essentially this DTB is loaded by the Linux kernel on boot to let it know which devices are connected and their configuration settings, very similar to what the BIOS component with x86-based architectures handles automatically.
Ultimately, the DTB concept and the use of overlays allow for easy configuration of such optional devices and GPIO pin settings, especially when made configurable through a simple text file as on the Raspberry Pi SBC platform.
As the world begins to slowly pull itself out of the economic effects of the pandemic, there’s one story that has been on our minds for the past couple of years, and it’s probably on yours too. The chip shortage born during those first months of the pandemic has remained with us despite the best efforts of the industry. Last year, pundits were predicting a return to normality in 2022, but will unexpected threats to production such as the war in Ukraine keep us chasing supplies? It’s time to delve into the root of the issue and get to the bottom of it for a Hackaday report.
The Chips Are Down
Consumers were more interested in toilet paper than chip supply during the lockdown.
Going back to 2020, and as global economies abruptly slowed down in the face of stringent lockdowns it’s clear that both chipmakers and their customers hugely underestimated the effect that the pandemic would have on global demand for chips.
As production capacity was reduced or turned to other products in response to the changed conditions, it was soon obvious that the customers’ hunger for chips had not abated, resulting in a shortfall between supply and demand.
We’ve all experienced the chaos that ensued as the supply of popular varieties dried up almost overnight, and as fresh pandemic waves have broken around the world along with a crop of climate and geopolitical uncertainties it’s left many wondering whether the chip situation will ever be the same again.
Green Shoots In Idaho
Idaho leads the way in a chip shortage recovery! inkknife_2000, CC BY-SA 2.0
Amidst all that gloom, there are some encouraging green shoots to be seen. While it’s perhaps not quite time to celebrate, there’s a possibility for some cautious optimism. This month brought the hope that Potato Semiconductor might be cutting the sod on a new production capacity for their ultra-fast digital logic in Idaho, and with other manufacturers following suit it could be that we’ll once again have all the chip capacity we can eat.
But the other side of the chip business coin lies with the customer: we all see the chip shortage from our own semi-insider perspective, but have the tastes of the general public returned towards chips? Early signs are that as consumer confidence returns there are encouraging trends in chip consumption taking root, so we’d be inclined to advise our readers to have cautious optimism. If all goes well, you’ll be having your chips by summer.
The prospects for a new dawn in chip production capacity in 2022 look rosy, but there’s a further snag on the horizon courtesy of the Russian invasion of Ukraine. Like so many industries in a globalised economy, the chip industry depends heavily on supplies, consumables, and machinery from beyond the borders of wherever the plants themselves may lie.
In the case of Ukraine there’s a particular raw material whose supply has been severely interrupted, and though we hope for a speedy resolution of the conflict and a consequent resumption of production, the knock-on effect on the production of chips in the rest of the world can not be underestimated. Despite the ramp-up in output led by Idaho, the production of chips globally still relies heavily on Ukrainian sunflower oil. There’s a possibility that an acceptable substitute might be found in canola oil, but it will remain to be seen whether the chip-eating consumers will notice the taste difference.
We are always impressed with something so simple can actually be so complex. For example, what would you think goes into an analog computer? Of course, a “real” analog computer has opamps that can do logarithms, square roots, multiply, and divide. But would it surprise you that you can make an analog device like a slide rule using a Wheatstone bridge — essentially two voltage dividers. You don’t even need any active devices at all. It is an old idea and one that used to show up in electronic magazines now and again. I’ll show you how they work and simulate the device so you don’t have to build it unless you just want to.
A voltage divider is one of the easiest circuits in the world to analyze. Consider two resistors Ra and Rb in series. Voltage comes in at the top of Ra and the bottom of Rb is grounded. The node connecting Ra and Rb — let’s call it Z — is what we’ll consider the output.
Let’s say we have a 10 V battery feeding A and a perfect voltmeter that doesn’t load the circuit connected to Z. By Kirchoff’s current law we know the current through Ra and Rb must be the same. After all, there’s nowhere else for it to go. We also know the voltage drop across Ra plus the voltage drop across Rb must equal to 10 V. Kirchoff, conservation of energy, whatever you want to call it. Let’s call these quantities I, Va, and Vb. Continue reading “Circuit VR: The Wheatstone Bridge Analog Computer”→
