An artist's depiction of a lystrosaurus munching on a prehistoric plant. It looks kind of like a hippo with a beak. The main body of the animal is grey-ish green and it's beak is ivory with two tusks jutting out from its top jaw.

Mammalian Ancestors Shed Light On The Great Dying

November 22, 2024 by Navarre Bartz 31 Comments

As we move through the Sixth Extinction, it can be beneficial to examine what caused massive die-offs in the past. Lystrosaurus specimens from South Africa have been found that may help clarify what happened 250 million years ago. [via IFLScience]

The Permian-Triassic Extinction Event, or the Great Dying, takes the cake for the worst extinction we know about so far on our pale blue dot. The primary cause is thought to be intense volcanic activity which formed the Siberian Traps and sent global CO₂ levels soaring. In Karoo Basin of South Africa, 170 tetrapod fossils were found that lend credence to the theory. Several of the Lystrosaurus skeletons were preserved in a spread eagle position that “are interpreted as drought-stricken carcasses that collapsed and died of starvation in and alongside dried-up water sources.”

As Pangea dried from increased global temperatures, drought struck many different terrestrial ecosystems and changed them from what they were before. The scientists say this “likely had a profound and lasting influence on the evolution of tetrapods.” As we come up on the Thanksgiving holiday here in the United States, perhaps you should give thanks for the prehistoric volcanism that led to your birth?

If you want to explore more about how CO₂ can lead to life forms having a bad day, have a look at paleoclimatology and what it tells us about today. In more recent history, have a look at how we can detect volcanic eruptions from all around the world and how you can learn more about the Earth by dangling an antenna from a helicopter.

A CO2 Traffic Light On An SAO

November 6, 2024 by Dave Rowntree 12 Comments

[David Bryant] clearly has an awareness of the impact of an excess concentration of CO₂ in the local environment and has designed an SAO board to add a CO₂ traffic light indicator to one of the spare slots on the official Hackaday Supercon 2024 badge.

The part used is the Sensirion SCD40 ‘true’ CO2 sensor, sitting atop an Adafruit rider board. [David] got a leg up on development by creating a simple SAO breakout board, which could have either the male and female connectors fitted, as required. Next, he successfully guessed that the badge would be based around the RP2040 running MicroPython and hooked up an Adafruit Feather RP2040 board to get started on some software to drive the thing. This made hooking up to the official badge an easy job. Since the SAO has only two GPIOs, [David] needed to decode these to drive the three LEDs. There are a few ways to avoid this, but he wanted to relive his earlier EE college years and do it the direct way using a pair of 74HC00 quad NAND gate chips.

We’ve seen a few CO₂ monitors over the years. This sleek little unit is based around the Seeeduino XIAO module and uses an LED ring as an indicator. Proper CO₂ monitors can be a little pricey, and there are fakes out there. Finally, CO₂ is not the only household pollutant; check out this project.

Pac-Man Ghost Helps With Air Quality Sensing

October 21, 2024 by Bryan Cockfield 13 Comments

In the past, building construction methods generally didn’t worry much about air quality. There were enough gaps around windows, doors, siding, and flooring that a house could naturally “breathe” and do a decent enough job of making sure the occupants didn’t suffocate. Modern buildings, on the other hand, are extremely concerned with efficiency and go to great lengths to ensure that no air leaks in or out. This can be a problem for occupants though and generally requires some sort of mechanical ventilation, but to be on the safe side and keep an eye on it a CO2 sensor like this unique Pac-Man-inspired monitor can be helpful.

Although there are some ways to approximate indoor air quality with inexpensive sensors, [Tobias] decided on a dedicated CO2 sensor for accuracy and effectiveness, despite its relatively large cost of around $30. An ESP32 handles the data from the sensor and then outputs the results to an array of LEDs hidden inside a ghost modeled after the ones from the classic arcade game Pac-Man. There are 17 WS2812B LEDs in total installed on a custom PCB, with everything held together in the custom 3D printed ghost-shaped case. The LEDs change from green to red as the air quality gets worse, although a few preserve the ghost’s white eyes even as the colors change.

For anyone looking to recreate this project and keep an eye on their own air quality, [Tobias] has made everything from the code, the PCB, and the 3D printer files open source, and has used accessible hardware in the build as well. Although the CO2 sensors can indeed be pricey, there are a few less expensive ways of keeping an eye on indoor air quality. Some of these methods attempt to approximate CO2 levels indirectly, but current consensus is that there’s no real substitute for taking this measurement directly if that’s the metric targeted for your own air quality.

An Earth-Bound Homage To A Martian Biochemistry Experiment

September 14, 2024 by Dan Maloney 5 Comments

With all the recent attention on Mars and the search for evidence of ancient life there, it’s easy to forget that not only has the Red Planet been under the figurative microscope since the early days of the Space Race, but we went to tremendous effort to send a pair of miniaturized biochemical laboratories there back in 1976. While the results were equivocal, it was still an amazing piece of engineering and spacefaring, one that [Marb] has recreated with this Earth-based version of the famed Viking “Labeled Release” experiment.

The Labeled Release experimental design was based on the fact that many metabolic processes result in the evolution of carbon dioxide gas, which should be detectable by inoculating a soil sample with a nutrient broth laced with radioactive carbon-14. For this homage to the LR experiment, [Marb] eschewed the radioactive tracer, instead looking for a relative increase in the much lower CO₂ concentration here on Earth. The test chamber is an electrical enclosure with a gasketed lid that holds a petri dish and a simple CO₂ sensor module. Glands in the lid allow an analog for Martian regolith — red terrarium sand — and a nutrient broth to be added to the petri dish. Once the chamber was sterilized, or at least sanitized, [Marb] established a baseline CO₂ level with a homebrew data logger and added his sample. Adding the nutrient broth — a solution of trypsinized milk protein, yeast extract, sugar, and salt — gives the bacteria in the “regolith” all the food they need, which increases the CO₂ level in the chamber.

More after the break…

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Cute CO2 Gauge Tells You When To Crack A Window

March 19, 2024 by Kristina Panos 25 Comments

[Cyrill] has a good home automation scheme going: there are a number of physical switches set around the place that control the essential functions. The only problem is that in the winter time, this results in a great deal of phone checking as [Cyrill] tries to monitor the CO₂ level. Tired of all this screen time, [Cyrill] set about to create an incredibly cute (and useful) Co₂ monitor that plainly shows the current level and how bad it is, relatively speaking.

A large servo and an ESP32-S2 make up the guts of an analog CO2 sensor.

Behind that adorable face is a DS3225 servo being driven by a Wemos S2 mini, both of which [Cyrill] happened to have handy. Although the 25 Kg servo may be complete overkill for the situation, [Cyrill] reports that it is quieter than your average AliExpress alternatives, which makes it well worth it in our book. Then it was on to Inkscape to make the gauge itself. [Cyrill] says they’re an Inkscape noob, but that face could have fooled us.

Finally, it was time to integrate it into Home Assistant to get readings from the CO₂ sensors. This was easier said than done, but [Cyrill] does a nice job of explaining how to get the ESP32-S2 up and working.

If you’re out there monitoring CO levels in your home, beware of fake sensors that cropped up during the height of the pandemic and are likely still at large.

Could Solar-Powered Airships Offer Cleaner Travel?

January 23, 2024 by Lewin Day 93 Comments

The blimp, the airship, the dirigible. Whatever you call them, you probably don’t find yourself thinking about them too often. They were an easy way to get airborne, predating the invention of the airplane by decades. And yet, they suffered—they were too slow, too cumbersome, and often too dangerous to compete once conventional planes hit the scene.

And yet! Here you are reading about airships once more, because some people aren’t giving up on this most hilarious manner of air travel. Yes, it’s 2024, and airship projects continue apace even in the face of the overwhelming superiority of the airplane.

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Dry Ice From Seashells, The Hard (But Cheap) Way

December 6, 2023 by Dan Maloney 11 Comments

[Hyperspace Pirate] wants to make his own dry ice, but he wants it to be really, really cheap. So naturally, his first stop is… the beach?

That’s right, the beach, because that’s where to find the buckets of free seashells that he turned into dry ice. Readers may recall previous efforts at DIY dry ice, which used baking soda and vinegar as a feedstock. We’d have thought those were pretty cheap materials for making carbon dioxide gas, but not cheap enough for [Hyperspace Pirate], as the dry ice he succeeded in making from them came out to almost ten bucks a pound. The low yield of the process probably had more to do with the high unit cost, in truth, so cheaper feedstocks and improved yield would attack the problem from both ends.

With a supply of zero-cost calcium carbonate from the beach and a homemade ZVS-powered induction heater tube furnace at the ready, [Hyperspace Pirate] was ready to make quicklime and capture the CO₂ liberated in the process. That proved to be a little more difficult than planned since the reaction needed not just heat but a partial vacuum to drive the CO₂ off. An oil-free vacuum pump helped, yielding a little CO₂, but eventually he knuckled under and just doused the shells in vinegar. This had the fun side effect of creating calcium acetate, which when distilled not only corrodes the copper still plumbing but also makes a lousy but still flammable grade of acetone. Once enough CO₂ was stored in a couple of beach balls, the process of cooling and condensing it into dry ice was pretty much the same as the previous method, except for taking advantage of the Joule-Thomson cryocooler he built a while back.

The result is a hundred or so grams of dry ice snow, which isn’t great but still shows promise. [Hyperspace Pirate] feels like the key to improving this process is more heat to really drive the calcination reaction. Might we suggest a DIY tube furnace for that job?

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