Follow The Bouncing Ball Of Entropy

When [::vtol::] wants to generate random numbers he doesn’t simply type rand() into his Arduino IDE, no, he builds a piece of art. It all starts with a knob, presumably connected to a potentiometer, which sets a frequency. An Arduino UNO takes the reading and generates a tone for an upward-facing speaker. A tiny ball bounces on that speaker where it occasionally collides with a piezoelectric element. The intervals between collisions become our sufficiently random number.

The generated number travels up the Rube Goldberg-esque machine to an LCD mounted at the top where a word, corresponding to our generated number, is displayed. As long as the button is held, a tone will continue to sound and words will be generated so poetry pours forth.

If this take on beat poetry doesn’t suit you, the construction of the Ball-O-Bol has an aesthetic quality that’s eye-catching, whereas projects like his Tape-Head Robot That Listens to the Floor and 8-Bit Digital Photo Gun showed the electronic guts front and center with their own appeal.

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Hackaday Prize Entry: An E-Ink Calendar

E-ink displays are becoming almost common in DIY electronics circles, and now we have very capable, low-power microcontrollers, some of which feature some sort of wireless connectivity. Combine these two, and you have the potential for a basic information screen — a low-power device that always displays some sort of relevant information, whether it’s the date or the weather.

For their Hackaday Prize entry, [Wenting] and [Dong] are building an e-ink calendar. It’s a calendar, it displays bitmaps, it can display the time, and with a little more hacking it can display the weather, current traffic, or train schedule. If this were the 90s, we would have called this an information appliance, and it would have blown everyone’s minds.

The current design of this e-ink calendar uses an 800 x 600 pixel display working in 16-level grayscale mode. The processor is an STM32F4, and in a cost-reducing revision, an external SRAM was thrown out and the frame buffer was moved to the internal RAM. The e-ink display is actually pretty quick, allowing for greater than 10 FPS in 1-bit mode.

As with any e-ink project, driving the display is a minor nightmare, but [Wenting] is able to push a few frames per second to the display. That’s good enough for a device that shouldn’t actually change all that much — this is a calendar, after all.

The Wrencher On The Road In The UK

Here at Hackaday, we are a team of technical writers who spend our days keeping abreast of the wonderful world of hardware as we write up the interesting things that cross our timelines and serve them up everyone to enjoy. That is however only part of the picture, the other half of the Hackaday family is you, our readers and our community. You are a wonderfully diverse group of people who do some fascinating things, and you are what gives us life.

From time to time, Hackaday makes it out on the road, we have events, we host meetups, and we spend time with you, the community of which we are a part. Of course, our world can be an annoyingly big place at times, so for a lot of us these meetups are too far away. As a Brit, for example, the upcoming Hackaday Superconference in Pasadena, California, is a somewhat unattainable dream without shelling out a significant chunk of the old hard-earned on travel.

In the very short term we must continue to disappoint many of our worldwide readers because we can’t have meetups all over the world and all at once. But we can at least provide succour to our British readers this month, with more than one opportunity to get to know Hackaday writers as we go out on the road.

In the first instance, I’m going to be in Hebden Bridge, Yorkshire this weekend. I’ll be giving a couple of talks, one on Friday at the Wuthering Bytes festival, and the other on Saturday at the Open Source Hardware Camp. I’ll be bringing along the remainder of my stock of Hackaday stickers left over from SHA Camp, and I’d love to see what you’ve been getting up to.

But worry not if you can’t make it to Yorkshire, for there is another chance for Brits to meet us this month. Our London Unconference on the 16th of September may have been a speedy sell-out, but because we have no wish to disappoint those of you who missed out on a ticket we’re also running a bring-a-hack meetup the night before. We’ve hired the Drawing Room at the Marquis Cornwallis, a pub not too far from Russell Square Tube station in London, so come and have a pint with us and show us what you’ve made. Get your skates on, it’s not much more than a couple of weeks away!

Building Set Limitations Make For Z-Height Follies

I’m working on a small CNC mill that uses a robotics building set as a starting point. I don’t know what to expect from the process. Maybe the connections will be too wobbly for the machine to be anything but a curiosity. Maybe I’ll be able to do pen plotting and balsa carving but nothing tougher than that. My goal is to have it carve PCBs, but what ultimately is important is that I have a tool whose awesomeness justifies the expense I’ve put into the project.

So far the process has been fun and interesting. But recently the Z-axis build has been especially so. It raises a really interesting question: where does the balance between unknown finished design and known material parameters fall?

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How Low-Power Can You Go?

[lasersaber] has a passion: low-power motors. In a bid to challenge himself and inspired by betavoltaic cells, he has 3D printed and built a small nuclear powered motor!

This photovoltaic battery uses fragile glass vials of tritium extracted from keychains and a small section of a solar panel to absorb the light, generating power. After experimenting with numerous designs, [lasersaber] went with a 3D printed pyramid that houses six coils and three magnets, encapsulated in a glass cloche and accompanied by a suitably ominous green glow.

Can you guess how much power and current are coursing through this thing? Guess again. Lower. Lower.

Under 200mV and 20nA!

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Ethereum: GPU Mining Is Back But For How Long?

By now, everyone and their dog has at least heard of Bitcoin. While no government will accept tax payments in Bitcoin just yet, it’s ridiculously close to being real money. We’ve even paid for pizza delivery in Bitcoin. But it’s not the only cryptocurrency in town.

Ethereum initially launched in 2015 is an open source, it has been making headway among the 900 or so Bitcoin clones and is the number two cryptocurrency in the world, with only Bitcoin beating it in value. This year alone, the Ether has risen in value by around 4000%, and at time of writing is worth $375 per coin. And while the Bitcoin world is dominated by professional, purpose-built mining rigs, there is still room in the Ethereum ecosystem for the little guy or gal.

Ethereum is for Hackers

There may be many factors behind Ethereum’s popularity, however one reason is that the algorithm is designed to be resistant to ASIC mining. Unlike Bitcoin, anyone with a half decent graphics card or decent gaming rig can mine Ether, giving them the chance to make some digital currency. This is largely because mining Ethereum coins requires lots of high-speed memory, which ASICs lack. The algorithm also has built-in ASIC detection and will refuse to mine properly on them.

Small-scale Bitcoin miners were stung when the mining technology jumped from GPU to ASICs. ASIC-based miners simply outperformed the home gamer, and individuals suddenly discovered that their rigs were not worth much since there was a stampede of people trying to sell off their high-end GPU’s all at once. Some would go on to buy or build an ASIC but the vast majority just stopped mining. They were out of the game they couldn’t compete with ASICs and be profitable since mining in its self uses huge amounts of electricity.

Economies of scale like those in Bitcoin mining tend to favor a small number of very large players, which is in tension with the distributed nature of cryptocurrencies which relies on consensus to validate transactions. It’s much easier to imagine that a small number of large players would collude to manipulate the currency, for instance. Ethereum on the other hand hopes to keep their miners GPU-based to avoid huge mining farms and give the average Joe a chance at scoring big and discovering a coin on their own computer.

Ethereum Matters

Ethereum’s rise to popularity has basically undone Bitcoin’s move to ASICs, at least in the gamer and graphics card markets. Suddenly, used high-end graphics cards are worth something again. And there are effects in new equipment market. For instance, AMD cards seem to outperform other cards at the moment and they are taking advantage of this with their release of Mining specific GPU drivers for their new Vega architecture. Indeed, even though AMD bundled its hottest RX Vega 64 GPU with two games, a motherboard, and a CPU in an attempt to make the package more appealing to gamers than miners, AMD’s Radeon RX Vega 56 sold out in five minutes with Ethereum miners being blamed.

Besides creating ripples in the market for high-end gaming computers, cryptocurrencies are probably going to be relevant in the broader economy, and Ethereum is number two for now. In a world where even banks are starting to take out patents on blockchain technology in an attempt to get in on the action, cryptocurrencies aren’t as much of a fringe pursuit as they were a few years ago. Ethereum’s ASIC resistance is perhaps its killer feature, preventing centralization of control and keeping the little hacker in the mining game. Only time will tell if it’s going to be a Bitcoin contender, but it’s certainly worth keeping your eye on.

An Environmentally Conscious, Solar-Powered Throwie

The basic throwie is a a type of street art/graffiti/vandalism — depending on where you stand — consisting of a coin cell, an led, and a magnet taped together. Seeking to be a slightly more eco-friendly troublemaker, [Alaric Loftus] has kindly put together an Instructable on how to build a solar-powered throwie!

In order to be the best maker of mischief possible, [Alaric Loftus] tried a number of different products to find one that was hackable,  supplied the right voltage, had the right form factor, and cheap enough to literally throw away. Turns out, garden path lights hit that sweet spot. Once [Alaric Loftus] has drilled a hole in the light and opened it up, de-soldering the stock LED, attaching some leads to the contacts and sticking it into the freshly-drilled hole is simply done. Hot-gluing a strong magnet on the bottom completes the throwie.

[Alaric Loftus] also advises that drilling the LED hole slightly smaller and sealing up any cracks with hot glue will strengthen its water resistance — because if it’s worth doing, it’s worth doing it right.

We’ve featured some really cooleven creepy — takes on the throwie concept, but please don’t contribute any further to e-waste buildup.