Author: Dan Maloney

3211 Articles

Sun On The Run: Diving Into Solar With A Mobile PV System

January 17, 2024 by 36 Comments

For obvious reasons, there has been a lot of interest in small-scale residential solar power systems lately. Even in my neck of the woods, where the sun doesn’t shine much from October to April, solar arrays are sprouting up on rooftops in a lot of local neighborhoods. And it’s not just here in suburbia; drive a little way out into the country or spend some time looking around in Google maps and it won’t take long to spy a sizable array of PV panels sitting in a field next to someone’s ranch house or barn.

Solar has gotten to the point where the expense of an installation is no longer a serious barrier to entry, at least if you’re willing to put in a little sweat equity and not farm the project out to a contractor. Doing it yourself requires some specialized tools and knowledge, though, over and above your standard suite of DIY skills. So, in the spirit of sharing hard-won knowledge, I decided to take the somewhat unusual step of writing up one of my personal projects, which has been in progress for a couple of years now and resulted in a solar power system that isn’t on a rooftop or a ground-mounted array at all, but rather is completely mobile: my solar trailer.

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Neutrino Hunters Hack Chat

January 15, 2024 by 1 Comment

Join us on Wednesday, January 17 at noon Pacific for the Neutrino Hunters Hack Chat with Patrick Allison!

It’s a paradox of science that the biggest of equipment is needed to study the smallest of phenomena. The bestiary of subatomic particles often requires the power and dimension of massive accelerators to produce, and caverns crammed with racks full of instruments to monitor their brief but energetic lives. Neutrinos, though, are different. These tiny, nearly massless, neutral particles are abundant in the extreme, zipping through space from sources both natural and artificial and passing through normal matter like it isn’t even there.

That poses a problem: how do you study something that doesn’t interact with the stuff you can make detectors out of? There are tricks that neutrino hunters use, and most of them use very, VERY big instruments to do it. Think enormous tanks of ultrapure water or a cubic kilometer of Antarctic ice, filled with photomultiplier tubes to watch for the slightest glimmer of Cherenkov radiation as a neutrino passes by.

join-hack-chatNeutrino hunting is some of the biggest of Big Science, and getting all the parts to work together takes some special engineering. Patrick Allison has been in the neutrino business for decades, both as a physicist and as the designated guru who keeps all the electronics humming. He’ll join us on the Hack Chat to talk about the neutrino hunting trade, and what it takes to keep the data flowing.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, January 17 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Featured image: Daderot, CC0, via Wikimedia Commons

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Hackaday Links: January 14, 2024

January 14, 2024 by 1 Comment

How long does it take a team of rocket scientists to remove two screws? When the screws they’re working on are keeping a priceless sample of asteroid safe, it’s about three months. That’s how long NASA has been working on the OSIRIS-REx sample return canister, which came back to Earth from asteroid Bennu back in September. The container was crammed full of asteroid bits, thanks in part to an overly energetic impact between the sample-collecting boom and Bennu. There was so much stuff that planetary scientists were able to recover about 70 grams of material that was covering the outside of the sealed container; this must have been a boon to the engineers, who got to figure out how to open the jammed cover of the container without anyone breathing down their necks for samples to study. The problem was a pair of stuck fasteners out of the 35 holding the lid on the container; the solution was far more complicated than a spritz of WD-40 and a little bit of heating with an oxy-acetylene torch. Engineers had to design two “clamp-like tools” and test them on a mock-up to make sure they wouldn’t contaminate the sample. We’d love to know more about these tools; trust us, we’ll be looking into this closely. If we find anything, a full article will be forthcoming.

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Reverse Engineering Smart Meters, Now With More Fuming Nitric Acid

January 13, 2024 by 14 Comments

If you’re lucky, reverse engineering can be a messy business. Sure, there’s something to be said for attacking and characterizing an unknown system and leaving no trace of having been there, but there’s something viscerally satisfying about destroying something to understand it. Especially when homemade fuming nitric acid is involved.

The recipient of such physical and chemical rough love in the video below is a residential electric smart meter, a topic that seems to be endlessly fascinating to [Hash]; this is far from the first time we’ve seen him take a deep dive into these devices. His efforts are usually a little less destructive, though, and his write-ups tend to concentrate more on snooping into the radio signals these meters are using to talk back to the utility company.

This time around, [Hash] has decided to share some of his methods for getting at these secrets, including decapping the ICs inside. His method for making fuming nitric acid from stump remover and battery acid is pretty interesting; although the laboratory glassware needed to condense the FNA approaches the cost of just buying the stuff outright, it’s always nice to have the knowledge and the tools to make your own. Just make sure to be careful about it — the fumes are incredibly toxic. Also detailed is a 3D-printable micropositioner, used for examining and photographing acid-decapped ICs under the microscope, which we’d bet would be handy for plenty of other microscopy jobs.

In addition to the decapping stuff, and a little gratuitous destruction with nitric acid, [Hash] takes a look at the comparative anatomy of smart meters. The tamper-proofing features are particularly interesting; who knew these meters have what amounts to the same thing as a pinball machine’s tilt switch onboard?

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Skip The Radio With This Software-Defined Ultrasound Data Link

January 13, 2024 by 21 Comments

We know what you’re thinking: with so many wireless modules available for just pennies, trying to create a physical data link using ultrasonic transducers like [Damian Bonicatto] did for a short-range, low-bitrate remote monitoring setup seems like a waste of time. And granted, there are a ton of simple RF protocols you can just throw at a job like this. Something like this could be done and dusted for a couple of bucks, right?

Luckily, [Damian] wanted something a little different for his wireless link to a small off-grid solar array, which is why he started playing with ultrasound in an SDR framework. The design for his “Software-Defined Ultrasonics” system, detailed in Part 1, has a pair of links, each with two ultrasonic transducers, one for receiving and one for transmitting. Both connect to audio amplifiers with bandpass filters; the received signal is digitized by the ADC built into an Arduino Nano, while the transmitted signal is converted to analog by an outboard DAC.

The transducers are affixed to 3D printed parabolic reflectors, which are aimed at each other over a path length of about 150′ (46 m). Part 2 of the series details the firmware needed to make all this work. A lot of the firmware design is dictated by the constraints introduced by using Arduinos and the 40-kHz ultrasonic carrier, meaning that the link can only do about 250 baud. That may sound slow, but it’s more than enough for [Damian]’s application.

Perhaps most importantly, this is one of those times where going slower helps you to go faster; pretty much everything about the firmware on this system applies to SDRs, so if you can grok one, the other should be a breeze. But if you still need a little help minding your Is and Qs, check out [Jenny]’s SDR primer.

A Homebrew GPS Correction System For DIY Land Surveying

January 12, 2024 by 60 Comments

For those of you rushing to the comment section after reading the title to tell [Ben Dauphinee] that his DIY land surveying efforts are for naught because only a licensed surveyor can create a legally binding property description, relax — he already knows. But what he learned about centimeter-resolution GPS is pretty interesting, especially for owners of large rural properties like him.

[Ben]’s mapping needs are less rigorous than an official survey; he just wants to get the locations of features like streams and wood lines, and to get topographic elevations so that he has a general “lay of the land” for planning purposes. He originally engaged a surveyor for that job, but after shelling out $4,600 to locate a single property line, he decided to see what else could be done. Luckily, real-time kinematics, or RTK, holds the key. RTK uses a fixed GPS station to provide correction signals to a mobile receiver, called a rover. If the fixed station’s position is referenced to some monument of known position, the rover’s position can be placed on a map to within a couple of centimeters.

To build his own RTK system, [Ben] used some modules from SparkFun. The fixed station has an RTK breakout board and a multi-band GNSS antenna to receive positioning data, along with a Raspberry Pi to run the RTK server. An old iPhone with a prepaid SIM provides backhaul to connect to the network that provides correction data. [Ben]’s rover setup also came mainly from SparkFun, with an RTK Facet receiver mounted on a photographer’s monopod. Once everything was set up and properly calibrated, he was able to walk his property with the rover and measure locations to within 4 centimeters.

This was not an inexpensive endeavor — all told, [Ben] spent about $2,000 on the setup. That’s a lot, especially on top of what he already paid for the legal survey, but still a fraction of what it would have cost to have a surveyor do it, or to buy actual surveyor’s equipment. The post has a ton of detail that’s worth reading for anyone interested in the process of mapping and GPS augmentation.

Retrotechtacular: Rebuilding A Fire-Ravaged Telephone Exchange

January 11, 2024 by 15 Comments

Those who haven’t experienced the destruction of a house fire should consider themselves lucky. The speed with which fire can erase a lifetime of work — or a life, for that matter — is stunning. And the disruption a fire causes for survivors, who often escape the blaze with only the clothes on their backs, is almost unfathomable. To face the task of rebuilding a life with just a few smoke-damaged and waterlogged possessions while wearing only pajamas and slippers is a devastating proposition.

As bad as a residential fire may be, though, its impact is mercifully limited to the occupants. Infrastructure fires are another thing entirely; the disruption they cause is often felt far beyond the building or facility involved. The film below documents a perfect example of this: the 1975 New York Telephone Exchange fire, which swept through the company’s central office facility at the corner of 2nd Avenue and 13th Street in Manhattan and cut off service to 300 blocks of the East Village and Lower East Side neighborhoods.

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