Hackaday Links: April 11, 2021

Hackaday Links Column Banner

Bad news, Martian helicopter fans: Ingenuity, the autonomous helicopter that Perseverance birthed onto the Martian surface a few days ago, will not be taking the first powered, controlled flight on another planet today as planned. We’re working on a full story so we’ll leave the gory details for that, but the short version is that while the helicopter was undergoing a full-speed rotor test, a watchdog timer monitoring the transition between pre-flight and flight modes in the controller tripped. The Ingenuity operations team is going over the full telemetry and will reschedule the rotor test; as a result, the first flight will occur no earlier than Wednesday, April 14. We’ll be sure to keep you posted.

Anyone who has ever been near a refinery or even a sewage treatment plant will have no doubt spotted flares of waste gas being burned off. It can be pretty spectacular, like an Olympic torch, but it also always struck us as spectacularly wasteful. Aside from the emissions, it always seemed like you could at least try to harness some of the energy in the waste gasses. But apparently the numbers just never work out in favor of tapping this source of energy, or at least that was the case until the proper buzzword concentration in the effluent was reached. With the soaring value of Bitcoin, and the fact that the network now consumes something like 80-TWh a year, building portable mining rigs into shipping containers that can be plugged into gas flaring stacks at refineries is now being looked at seriously. While we like the idea of not wasting a resource, we have our doubts about this; if it’s not profitable to tap into the waste gas stream to produce electricity now, what does tapping it to directly mine Bitcoin really add to the equation?

What would you do if you discovered that your new clothes dryer was responsible for a gigabyte or more of traffic on your internet connection every day? We suppose in this IoT world, such things are to be expected, but a gig a day seems overly chatty for a dryer. The user who reported this over on the r/smarthome subreddit blocked the dryer at the router, which was probably about the only realistic option short of taking a Dremel to the WiFi section of the dryer’s control board. The owner is in contact with manufacturer LG to see if this perhaps represents an error condition; we’d actually love to see a Wireshark dump of the data to see what the garrulous appliance is on about.

As often happens in our wanderings of the interwebz to find the very freshest of hacks for you, we fell down yet another rabbit hole that we thought we’d share. It’s not exactly a secret that there’s a large number of “Star Trek” fans in this community, and that for some of us, the way the various manifestations of the series brought the science and technology of space travel to life kick-started our hardware hacking lives. So when we found this article about a company building replica Tricorders from the original series, we followed along with great interest. What we found fascinating was not so much the potential to buy an exact replica of the TOS Tricorder — although that’s pretty cool — but the deep dive into how they captured data from one of the few remaining screen-used props, as well as how the Tricorder came to be.

And finally, what do you do if you have 3,281 drones lying around? Obviously, you create a light show to advertise the launch of a luxury car brand in China. At least that’s what Genesis, the luxury brand of carmaker Hyundai, did last week. The display, which looks like it consisted mostly of the brand’s logo whizzing about over a cityscape, is pretty impressive, and apparently set the world record for such things, beating out the previous attempt of 3,051 UAVs. Of course, all the coverage we can find on these displays concentrates on the eye-candy and the blaring horns of the soundtrack and gives short shrift to the technical aspects, which would really be interesting to dive into. How are these drones networked? How do they deal with latency? Are they just creating a volumetric display with the drones and turning lights on and off, or are they actually moving drones around to animate the displays? If anyone knows how these things work, we’d love to learn more, and perhaps even do a feature article.

30 thoughts on “Hackaday Links: April 11, 2021

  1. “Effluent” and “garrulous” were both obscure enough to force me to research their definitions. I’m sure your wordcraft annoys a handful of readers who want HaD to read like an instruction manual, but I appreciate it.

    1. Bear in mind that it’s hard to know what words someone else will know. “Effluent” seems like a pretty normal word to me, and “garrulous” only slightly refined from completely normal.

    2. I love Dan’s stories. And fully appreciate your comment, JB, but I suppose one reason I like Dan’s writing so much is that “effluent” and “garrulous” were already in my lexicographical wheelhouse, as they may have been for a few other HaD fans. :-)

  2. Just out of kindness, don’t start an article about Ingenuity with “Bad News” w/o stating “delay” in the title because the first assumption will be that Ingenuity crashed!

    I’m fully okay with a few delays with Ingenuity’s first flight if it means we can be “more certain” (remember: we’ve never done this before!) that Ingenuity will survive so that… with luck, maybe we’ll get multiple flights.

    I guess I’m old school enough (born ’79) that I’m still flabbergasted (super amazed and blown away) just by the powered decent of the rover (which turns out is 2nd time!) that… Ingenuity – trying to fly a drone on Mars… is so awesomesauce crazy I’m totally okay if they delay a bit if they think that extra data (or work out the bugs like this) gives the chance for Ingenuity to do a few more hops than planned.

    1. I realized a couple years ago that clickbait is a really interesting concept of negative information: it not only doesn’t tell you anything, it tells you that there’s something to know that you don’t know.

      1. And then the article in question continues to tell you nothing you didn’t already know, which completes the circle.

        Meanwhile, the ad revenue from displaying the article gets paid by other people – well, all the people – so you don’t face much of a penalty for clicking on bait articles, which is what makes the whole thing extremely immoral.

  3. “Ingenuity… will not be taking the first powered, controlled flight on another planet today as planned.”

    Holy crap! I’m used to delayed flights on Earth, but now we have them on other planets!? What next is Perseverance going to lose luggage?

    “What would you do if you discovered that your new clothes dryer was responsible for a gigabyte or more of traffic”?

    I’d take it back and get a f**king clothes line!

  4. “if it’s not profitable to tap into the waste gas stream to produce electricity now, what does tapping it to directly mine Bitcoin really add to the equation?”: Easy. A mining rig is small enough to be sited where the gas is burned, so you save the expense of moving the gas. Bitcoin is just data, so there’s no expense in moving the thing you create with the energy.

    1. Ithaca, NY has a sewage treatment plant whose pumps and constrol systems were driven by locally harvested methane when I toured it in my 8th grade science class. That was some 30 years back but I imagine they still use it. They still burned some off when the rotting sewage produced more methane than they could use.

      1. Yeah, this has always seemed odd to me. We have local refineries with flareoffs, right beside old garbage dumps where they collect the evolved gas and run power generation turbines off of the gas. I suspect this is more an organizational thing, like the company running the refinery doesn’t want the liability of having a gas turbine on site and allowing access to the power company’s employees. Our refineries have robust security due to their importance.
        (But why can’t they pipe it offsite? The one I know the best already has a handful of 20cm lines that leave the refinery site and cross a river and a roadway to go to a much smaller refinery nearby.)
        About 15 years ago they spent around a billion dollars rebuilding the refinery and afterwards it only had two flareoff towers rather than the fifteen or so it had before. The old one had lots of yellow flames (poor combustion, maybe complex/longer carbon/unsaturated) while the new one only has blue flames (good oxygen mix, possibly only short-chain combustion.)

        1. The methane that comes out of a compost heap is actually something like 30-60% CO2 which makes it burn really badly – hence the yellow flames. If you dilute it with more air, it doesn’t burn anymore.

          Cryogenic distillation is used for separating the gases, and more recently MOFs and semi-permeable membranes are getting improvements, but it still costs a load of money to “upgrade” the gas into something you can put into a generator set unless it’s already low on CO2.


          Anaerobic condition, like a covered landfill, produce more pure methane than sewage which has oxygen to consume, which makes sewage derived methane more expensive to use.

          1. You didn’t read his post correctly. They are apparently ALREADY running turbines on compost gas, the question is why the refinery next door doesn’t do the same with their nice, clean methane (or sell it to the garbage plant).

        2. The refinery is probably either using their flares intermittently (for emergencies, purging systems during startup/shutdown, etc.) or to dispose of some kind of byproduct (which could be amounts of methane too small or contaminated to economically use/sell). If they had plenty of reasonably pure methane, they’d either be burning it in a turbine for power, using it for another process, or selling it.

          Flare design is not entirely trivial, especially if you have to deal with variable inputs (source: spent several weeks last summer trying to get our flare to work consistently). The new flares probably have better flames because they are improved designs.

          An on-site turbine would not require giving access to electric utility employees, the refinery could use all the power itself.

    2. Well, except the expense of the satellite links and hardware, etc.

      The thing is, bitcoin doesn’t produce anything of value, it merely shifts money from other pockets to speculators’ pockets, so if you can do it for “free” with waste energy, that merely makes it cheaper to swindle people. It’s still a net negative value and should not be done in the first place.

      1. Besides, the flared gas from a sewage treatment plant is mixed with great quantities of CO2 and barely burns. You need a gas separator to turn it into pure methane, which also costs a load of money.

  5. One time, I suddenly noticed a log file was getting large. I look, and it’s the DVD drive. Every operation generated lines of errors.

    Putting in a new drive fixed that. So maybe the dryer is faulty.

  6. Hmmm … gas flaring … bitcoin? Well since we have dogecoin as a meme currency, has somebody already created “FartCoin”? I’d buy a million of those at $0.000001 each! Maybe if I could get Elon to tweet about it, I could launch my own helicopter on Mars.

  7. There is a public swimming pool near me (uk) with water that has been warmed by the neighbouring sewerage treatment plant since at least the 1960s. But I’m not sure what the mechanism is (yes the water is clear!)

  8. Canberra (Australia) recently signed a contract for landfill gas recovery. I’m not sure if they clean it and inject it into the reticulated network to be burned, or if they burn it onsute to generate electricity. I think it’s the latter. From memory, the whole system is as much to reduce the risk of fire/explosion/smell from methane buildup as it it is to generate fuel/electricity.

Leave a Reply

Please be kind and respectful to help make the comments section excellent. (Comment Policy)

This site uses Akismet to reduce spam. Learn how your comment data is processed.