Home Heating With Bitcoin Miners Is Now A Real Thing

May 13, 2023 by Tom Nardi 64 Comments

If you were reading this post a month ago, you could have been forgiven for thinking it was an April Fools post. But we assure you, this is no joke. A company called HeatBit has recently opened preorders for their second generation of Bitcoin miner that doubles as a space heater.

The logic goes something like this: if you’re going to be using an electric space heater anyway, which essentially generates heat by wasting a bunch of energy with a resistive element, why not replace that element with a Bitcoin miner instead? Or at least, some of the element. The specs listed for the HeatBit Mini note that the miner itself only consumes 300 watts, which is only responsible for a fraction of the device’s total heat output. Most of the thermal work is actually done by a traditional 1000 watt heater built inside the 46 cm (18 inch) tall cylindrical device.

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Remembering Virginia Norwood, Mother Of NASA’s Landsat Success

May 13, 2023 by Donald Papp 13 Comments

Virginia T. Norwood passed away earlier this year at the age of 96, and NASA’s farewell to this influential pioneer is a worth a read. Virginia was a brilliant physicist and engineer, and among her other accomplishments, we have her to thank for the ongoing success of the Landsat program, which continues to this day.

The goal of the program was to image land from space for the purpose of resource management. Landsat 1 launched with a Multispectral Scanner System (MSS) that Norwood designed to fulfill this task. Multispectral imaging was being done from aircraft at the time, but capturing this data from space — not to mention deciding which wavelengths to capture — and getting it back down to Earth required solving a whole lot of new and difficult problems.

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Tools Of The Trade: Dirt Cheap Or Too Dirty?

May 13, 2023 by Elliot Williams 69 Comments

We’ve recently seen a couple reviews of a particularly cheap oscilloscope that, among other things, doesn’t meet its advertised specs. Actually, it’s not even close. It claims to be a 100 MHz scope, and it’s got around 30 MHz of bandwidth instead. If you bought it for higher frequency work, you’d have every right to be angry. But it’s also cheap enough that, if you were on a very tight budget, and you knew its limitations beforehand, you might be tempted to buy it anyway. Or so goes one rationale.

In principle, I’m of the “buy cheap, buy twice” mindset. Some tools, especially ones that you’re liable to use a lot, make it worth your while to save up for the good stuff. (And for myself, I would absolutely put an oscilloscope in that category.) The chances that you’ll outgrow or outlive the cheaper tool and end up buying the better one eventually makes the money spent on the cheaper tool simply wasted.

But that’s not always the case either, and that’s where you have to know yourself. If you’re only going to use it a couple times, and it’s not super critical, maybe it’s fine to get the cheap stuff. Or if you know you’re going to break it in the process of learning anyway, maybe it’s a shame to put the gold-plated version into your noob hands. Or maybe you simply don’t know if an oscilloscope is for you. It’s possible!

And you can mix and match. I just recently bought tools for changing our car’s tires. It included a dirt-cheap pneumatic jack and an expensive torque wrench. My logic? The jack is relatively easy to make functional, and the specs are so wildly in excess of what I need that even if it’s all lies, it’ll probably suffice. The torque wrench, on the other hand, is a bit of a precision instrument, and it’s pretty important that the bolts are socked up tight enough. I don’t want the wheels rolling off as I drive down the road.

Point is, I can see both sides of the argument. And in the specific case of the ’scope, the cheapo one can also be battery powered, which gives it a bit of a niche functionality when probing live-ground circuits. Still, if you’re marginally ’scope-curious, I’d say save up your pennies for something at least mid-market. (Rigol? Used Agilent or Tek?)

But isn’t it cool that we have so many choices? Where do you buy cheap? Where won’t you?

Tiny Bitcoin Miner Plays The Lottery

May 13, 2023 by Bryan Cockfield 113 Comments

Usually when we think of Bitcoin miners, we imagine huge facilities of server racks doing nothing but essentially wasting energy, all for the chance that one of those computers amongst the rows will stumble upon the correct set of numbers to get rewarded with imaginary money. The idea being that the more computers, the more chances to win. But just buying one lottery ticket is the only thing technically required to win, at least in theory. And [Data Slayer] is putting this theory to the test with this Bitcoin miner built around a single Raspberry Pi.

This tiny Raspberry Pi Zero does get a little bit of support from an Ant Miner, a USB peripheral which is optimized to run the SHA256 hashing algorithm and solve the complex mathematical operations needed to “win” the round of Bitcoin mining. Typically a large number of these would be arrayed together to provide more chances at winning (or “earning”, to use the term generously) Bitcoin but there’s no reason other than extreme statistical improbability that a single one can’t work on its own. The only other thing needed to get this setup working is to give the Pi all of the configuration information it needs such as wallet information and pool information.

This type of miner isn’t novel by any means, and in fact it’s a style of mining cryptocurrency called “lottery mining” where contributing to a pool is omitted in favor of attempting to solve the entire block by pure random chance alone in the hopes that if it’s solved, the entire reward will be claimed by that device alone. In the case of this device, the current hash rate calculated when it was contributing to a pool means that when lottery mining, it has about a one-in-two-billion chance of winning. That’s essentially zero, which is basically the same chance of winning a lottery that pays out actual usable currency.

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Passively Generating Power Day And Night Takes The Right Parts

May 13, 2023 by Donald Papp 18 Comments

A thermoelectric generator (TEG) can turn a temperature difference into electricity, and while temperature differentials abound in our environment, it’s been difficult to harness them into practical and stable sources of power. But researchers in China have succeeded in creating a TEG that can passively and continuously generate power, even across shifting environmental conditions. It’s not a lot of power, but that it’s continuous is significant, and it could be enough for remote sensors or similar devices.

Historically, passive TEGs have used ambient air as the “hot” side and some form of high-emissivity heat sink — usually involving exotic materials and processes — as the “cold” side. These devices work, but fail to reliably produce uninterrupted voltage because shifting environmental conditions have too great of an effect on how well the radiative cooling emitter (RCE) can function.

The black disk (UBSA) heats the bottom while the grey square (RCE) radiates heat away, ensuring a workable temperature differential across a variety of conditions.

Here is what has changed: since a TEG works on temperature difference between the hot and cold sides, researchers improved performance by attaching an ultra-broadband solar absorber (UBSA) to the hot side, and an RCE to the cold side. The UBSA is very good at absorbing radiation (like sunlight) and turning it into heat, and the RCE is very good at radiating heat away. Together, this ensures enough of temperature difference for the TEG to function in bright sunlight, cloudy sunlight, clear nighttime, and everything in between.

As mentioned, it’s not a lot of power (we’re talking millivolts) but the ability to passively and constantly produce across shifting environmental conditions is something new. And as a bonus, the researchers even found a novel way to create both UBSA and RCE using non-exotic materials and processes. The research paper with additional details is available here.

The ability to deliver uninterrupted power — even in tiny amounts — is a compelling goal. A few years ago we encountered a (much larger) device from a team at MIT that also aimed to turn environmental temperature fluctuations into a trickle of constant power. Their “Thermal Resonator” worked by storing heat in phase-change materials that would slowly move heat across a TEG, effectively generating continuously by stretching temperature changes out over time.

A Non-Destructive Digital Back For A Classic Leica

May 12, 2023 by Jenny List 16 Comments

As digital photography has become so good, perhaps just too good, at capturing near-perfect pictures, some photographers have ventured back into the world of film. There they have found the imperfections requiring technical skill to cope with that they desire, but they’ve also come face-to-face with the very high cost and sometimes sketchy availability of film stocks. From this has come the so-called post-digital movement which marries analog cameras and lenses with digital sensors, and of this a particularly nice example comes from [Michael Suguitan]. He’s taken a classic Leica M2 rangefinder camera, and built a new back for it containing a Raspberry Pi Zero and sensor.

Perhaps the best thing about this conversion, and something which should propagate forward into other builds, is the way it does not hack or modify the original camera beyond the replacement of the already-removable back. A vintage Leica is a pricey item, so it would be a foolhardy hacker who would proceed to gut it for a digital conversion. Instead he’s mounted everything that makes a digital camera, the sensor, Pi Zero, and screen board, behind the camera body. The Pi shutter trigger comes from the Leica’s flash terminal, meaning that there’s plenty of time for it to take a photo while the shutter is open.

He’s admirably preserved the usage and properties of the Leica, and his photographs as can be seen in the video below the break bear testament to what is possible with the camera. He still has to work with the tiny sensor size though, meaning that all photographs are at a much higher zoom level than on the original. We would love to see a camera conversion like this one that incorporates appropriate lenses to bring the picture to focus on this small sensor.

We won’t own a Leica any time soon, but we like this conversion. It’s by far the most sympathetic, but it’s not the first rangefinder conversion we’ve seen.

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3D Design With Text-Based AI

May 12, 2023 by Bryan Cockfield 8 Comments

Generative AI is the new thing right now, proving to be a useful tool both for professional programmers, writers of high school essays and all kinds of other applications in between. It’s also been shown to be effective in generating images, as the DALL-E program has demonstrated with its impressive image-creating abilities. It should surprise no one as this type of AI continues to make in-roads into other areas, this time with a program from OpenAI called Shap-E which can render 3D images.

Like most of OpenAI’s offerings, this takes plain language as its input and can generate relatively simple 3D models with this text. The examples given by OpenAI include some bizarre models using text prompts such as a chair shaped like an avocado or an airplane that looks like a banana. It can generate textured meshes and neural radiance fields, both of which have various advantages when it comes to available computing power, training methods, and other considerations. The 3D models that it is able to generate have a Super Nintendo-style feel to them but we can only expect this technology to grow exponentially like other AI has been doing lately.

For those wondering about the name, it’s apparently a play on the 2D rendering program DALL-E which is itself a combination of the names of the famous robot WALL-E and the famous artist Salvador Dali. The Shap-E program is available for anyone to use from this GitHub page. Even though this code comes from OpenAI themselves, plenty are speculating that the AI revolution to come will largely come from open-source sources rather than OpenAI or Google, something for which the future is somewhat hazy.