Ourobot: What Happens When A Snake Bot Swallows Its Own Tail

July 20, 2016 by Elliot Williams 21 Comments

For all their joking about “reinventing the wheel”, the team behind Ourobot made a very cool robot (German, automatic translation here). The team, at the University of Applied Sciences in “Bielefeld, Germany“, built their wheel out of twelve segments, each with its own servo motor, a 3D-printed case, and a pressure sensor mounted on the outside of the wheel. The latter, plus some clever programming, allows the robot wheel to vary its circular gate and climb up over obstacles automatically.

There are a bunch of interesting constraints in designing the control for this bot. The tracks on the ground, naturally, have to adjust their relative angles so that they lie each flat on the surface, even if that surface isn’t itself flat or level. The segments in the air are unconstrained, but the sum of all the servos’ interior angles has to add up to 1800 degrees, and these angles control where its center of gravity is.

Our head is spinning. The paper, “OUROBOT – A Self-Propelled Continuous-Track-Robot for Rugged Terrain” is unfortunately behind the IEEE paywall, but goes into detail if you can find it. Continue reading “Ourobot: What Happens When A Snake Bot Swallows Its Own Tail” →

Hot Russian Tubes

July 20, 2016 by Elliot Williams 33 Comments

On the heels of our post on retro-Soviet transistor teardowns and die-shots, [nikitas] wrote in to tell us about a huge thread on rare vacuum devices of all varieties: oddball cathode-ray tubes, obscure Nixies, and strange Soviet valves. We thought the other forum post was overwhelming at just over 110 pages, but how about 391 pages (and counting) of blown-glass electronics?

If you read through the decaptholon, we mentioned that a particularly enthusiastic poster, [lalka], looked to be cataloguing every Soviet oscillator circuit. It turns out that he’s also the one behind this incredible (random) compendium of everything that’s had the air sucked out of it.

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What Could Go Wrong? I2C Edition

July 19, 2016 by Elliot Williams 53 Comments

I should really like I2C more than I do. In principle, it’s a brilliant protocol, and in comparison to asynchronous serial and SPI, it’s very well defined and clearly standardized. On paper, up to 127 devices can be connected together using just two wires (and ground). There’s an allowance for multiple clock-masters on the same bus, and a way for slaves to signal that the master needs to wait. It sounds perfect.

In reality, the tradeoff for using only two wires is a significantly complicated signalling and addressing system that brings both pitfalls and opportunities for debugging. Although I2C does reduce the number of signal wires you need, it gets dangerous when you have more than a handful of devices on the same pair of wires, and you’re lucky when they all conform to the same standard. I’ve never seen twenty devices on a bus, much less 127.

But still, I2C has its place. I2C was designed to connect up a bunch of slower, cheaper devices without using a lot of copper real estate compared to its closest rival protocol: SPI. If you need to connect a few cheap temperature sensors to a microcontroller (and their bus addresses don’t clash) I2C is a great choice. So here’s a guide to making it work when it’s not working.

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Never Gonna Give Up Free WiFi

July 19, 2016 by Elliot Williams 44 Comments

Our conscience almost prevented us from posting this one. Almost.

What do people all around the world want most? Free WiFi. And what inevitable force do they want to avoid most, just after death and taxes? Rick Astley. As a getting-started project with the ESP8266, Hackaday.io user [jaime] built a “free WiFi portal” that takes advantage of people’s deepest desires. Instead of delivering sweet, high-bandwidth connectivity, once you click through the onerous terms and conditions, it delivers you a looped GIF with background music.

And all of this on $4 worth of hardware, with firmware assembled in the cloud and easily available to anyone. We live in a truly ~~frivolous~~ glorious age.

Digging through our archives, we found a number of Rickroll posts that we’d rather forget, but this steam-powered record player bears a second look.

SoftBank Bought ARM

July 18, 2016 by Elliot Williams 44 Comments

$32 billion USD doesn’t buy as much as it used to. Unless you convert it into British Pounds, battered by the UK’s decision to leave the European Union, and make an offer for ARM Holdings. In that case, it will buy you our favorite fabless chip-design company.

The company putting up 32 Really Big Ones is Japan’s SoftBank, a diversified technology conglomerate. SoftBank is most visible as a mobile phone operator in Japan, but their business strategy lately has been latching on to emerging technology and making very good investments. (With the notable exception of purchasing the US’s Sprint Telecom, which they say is turning around.) Recently, they’ve focused on wireless and IoT. And now, they’re going to buy ARM.

We suspect that this won’t mean much for ARM in the long term. SoftBank isn’t a semiconductor firm, they just want a piece of the action. With the Japanese economy relatively stagnant, a strong Yen and a weak Pound, ARM became a bargain. (SoftBank said in a press release that the Brexit didn’t affect their decision, and that they would have bought ARM anyway. Still, you can’t blame them for waiting until after the vote, and the fallout, to make the purchase.) It certainly won’t hurt SoftBank’s robotics, IoT, or AI strategies to have a leading processor design firm in their stable, but we predict business as usual for those of us way downstream in the ARM ecosystem.

Thanks [Jaromir] for the tip!

Russian Decapping Madness

July 18, 2016 by Elliot Williams 37 Comments

It all started off innocently enough. [mretro] was curious about what was inside a sealed metal box, took a hacksaw to it and posted photographs up on the Interwebs. Over one hundred forum pages and several years later, the thread called (at least in Google Translate) “dissecting room” continues to amaze.

If you like die shots, decaps, or teardowns of oddball Russian parts, this is like drinking from a firehose. You can of course translate the website, but it’s more fun to open it up in Russian and have a guess at what everything is before peeking. (Hint: don’t look at the part numbers. NE555 is apparently “NE555” in Russian.)

From a brief survey, a lot of these seem to be radio parts, and a lot of it is retro or obsolete. Forum user [lalka] seems to have opened up one of every possible Russian oscillator circuit. The website loads unfortunately slowly, at least where we are, but bear in mind that it’s got a lot of images. And if your fingers tire of clicking, note that the URL ends with the forum page number. It’d be a snap to web-scrape the whole darn thing overnight.

We love teardowns and chip shots, of old gear and of new. So when you think you’ve got a fake part, or if you need to gain access to stuff under that epoxy blob for whatever reason, no matter how embarrassing, bring along a camera and let us know!

Thanks [cfavreau] for the great tip!

Video Games In As Few Dimensions As Possible

July 17, 2016 by Elliot Williams 34 Comments

First there were text games, then came 2D dungeons. When Wolfenstein 3D broke out on the gaming scene, it created quite a fuss. But if all you’ve got is a strip of WS2812 LEDs, those are a few dimensions too many.

[treibair] has started up a project on Hackaday.io to develop 1D video games to be played on a single LED strip. While the end application is something with a cool physical interface, probably driven by a microcontroller, prototyping is a lot easier on the big computer. He’s writing it in Processing, though, so that the transition to the Arduino is easier in the end.

There are a couple of other games out there in 1D, including Line Wobbler (YouTube) and, naturally, Wolfenstein 1D. We even saw a one-dimensional “snake” clone at Make Munich a few months back. (Would the author please stand up?)

We think the idea is a good one, and lining up everyone’s 1D gaming experience in one place would be a great help. So link up code and reviews in the comments!

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