A Motherboard Manufacturer’s Take On A Raspberry Pi Competitor

In the almost five years since the launch of the original Raspberry Pi we have seen a huge array of competitors emerge in the inexpensive single board computer market. Many have created their own form factors, but an increasing number have gone straight for the jugular of the fruity board from Cambridge by copying its form factor and interfaces as closely as possible. We’ve seen sterling efforts from the likes of Banana Pi, Odroid, and several others, but none have yet succeeded in toppling it from its pedestal.

The ASUS Tinker specification.
The ASUS Tinker specification.

The latest contender in this arena might just make more of an impact though, because it comes from a major manufacturer, a name you will have heard of. Asus have quietly released their Tinker, board that follows the Pi form factor very closely, and packs a 1.8 GHz quad-core ARM Cortex A17 alongside an impressive spec we’ve captured as an image for this article. Though they are reticent about it on their website, there is a SlideShare presentation with some of the details, which we’ve placed below the break.

At £55 (about $68) where this is being written it’s more expensive than the Pi, but Asus go to great lengths to demonstrate that it is significantly faster. We will no doubt verify the accuracy of that claim as the boards find their way into the hands of our community. Still, it features a mostly-Pi-compatible I/O header, and the same display and camera connectors as the Pi. There is no information as to how compatible these last two are though.

Other boards in this arena have boasted impressive hardware, but have fallen down when it comes to the support for their operating systems. When you buy a Raspberry Pi it is not just the hardware you are taking on but the Raspbian operating system and its impressive community support. The Tinker supports Debian, so if Asus is to make a mark they must ensure that its support rivals that of the board it is targeting. If they succeed in that endeavor then the result can only be good news for us.

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Optimizing Linux for Slow Computers

It’s interesting, to consider what constitutes a power user of an operating system. For most people in the wider world a power user is someone who knows their way around Windows and Microsoft Office a lot, and can help them get their print jobs to come out right. For those of us in our community, and in particular Linux users though it’s a more difficult thing to nail down. If you’re a LibreOffice power user like your Windows counterpart, you’ve only really scratched the surface. Even if you’ve made your Raspberry Pi do all sorts of tricks in Python from the command line, or spent a career shepherding websites onto virtual Linux machines loaded with Apache and MySQL, are you then a power user compared to the person who knows their way around the system at the lower level and has an understanding of the kernel? Probably not. It’s like climbing a mountain with false summits, there are so many layers to power usership.

So while some of you readers will be au fait with your OS at its very lowest level, most of us will be somewhere intermediate. We’ll know our way around our OS in terms of the things we do with it, and while those things might be quite advanced we’ll rely on our distribution packager to take care of the vast majority of the hard work.

Linux distributions, at least the general purpose ones, have to be all things to all people. Which means that the way they work has to deliver acceptable performance to multiple use cases, from servers through desktops, portable, and even mobile devices. Those low-level power users we mentioned earlier can tweak their systems to release any extra performance, but the rest of us? We just have to put up with it.

To help us, [Fabio Akita] has written an excellent piece on optimizing Linux for slow computers. By which he means optimising Linux for desktop use on yesterday’s laptop that came with Windows XP or Vista, rather than on that ancient 486 in the cupboard. To a Hackaday scribe using a Core 2 Duo, and no doubt to many of you too, it’s an interesting read.

In it he explains the problem as more one of responsiveness than of hardware performance, and investigates the ways in which a typical distro can take away your resources without your realising it. He looks at RAM versus swap memory, schedulers, and tackles the thorny question of window managers head-on. Some of the tweaks that deliver the most are the easiest, for example the Great Suspender plugin for Chrome, or making Dropbox less of a hog. It’s not a hardware hack by any means, but we suspect that many readers will come away from it with a faster machine.

If you’re a power user whose skills are so advanced you have no need for such things as [Fabio]’s piece, share your wisdom on sharpening up a Linux distro for the rest of us in the comments.

Via Hacker News.

Header image, Tux: Larry Ewing, Simon Budig, Garrett LeSage [Copyrighted free use or CC0], via Wikimedia Commons.

[Marla]’s New Arm

It is especially rare to see coverage in the mainstream media that involves a hackspace, so it was a pleasant surprise yesterday when the local TV news where this is being written covered a story that not only highlighted a hackspace’s work, but did so in a very positive light.

[Marla Trigwell] is a young girl from Newbury, UK, who was born without a left hand. She had been provided with prosthetics, but they aren’t cheap, and as a growing child she quickly left them behind. Her parents researched the problem as modern parents do, and found out about recent advances in 3D-printed prosthetics lowering the bar to access for those like [Marla] born without a limb. Last month [Marla] received her new 3D-printed arm, and she did so courtesy of the work of [Andrew Lindsay] at Newbury and District Hackspace.

The arm itself is a Team Unlimbited arm version 2.0 Alfie edition, which can be found on Thingiverse with full sizing instructions for adjusting to the recipient in Customizer. As the video below the break shows, [Marla] appears very pleased with it, and is soon mastering its ability to grip objects.

This story is a fantastic demonstration of the ability of a hackspace to be a force for good, a true community organisation. We applaud [Andrew], NADHack, and all involved with it for their work, and hope that 3D printed arms will keep [Marla] with a constant supply of comfortable and affordable prosthetics as she grows up.

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Use A Brushless Motor As A Rotary Encoder

The electric motor is the fundamental building block of almost all robotic projects but, without some form of feedback, it lacks the precise positional control required for the task. Small servos from the modelling world will often use a potentiometer to sense where they are on their travel, while more accomplished motors will employ some form of shaft encoder.

Commercial shaft encoders use magnets and Hall-effect sensors, or optical sensors and encoder discs. But these can be quite expensive, so [Hello1024] hacked together an alternative in an afternoon. It uses another motor as the encoder, taking advantage of the minute changes in inductance as the magnet passes each of its coils. It’s a technique that works better with cheaper motors, as their magnets are more imperfect than those on their expensive cousins.

The sensing is rather clever in its economy, sending a pulse to the motor through an off the shelf motor controller and measuring the time it takes to decay through the body diode of the driving MOSFET. It requires a calibration procedure before first use, and it is stressed that the whole thing is very much still in beta, but it’s a very impressive hack nevertheless. He’s posted a video demonstration which you can see below the break.

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A Bold Experiment In A Decentralised Low Voltage Local DC Power Grid

January, for many of us in the Northern Hemisphere, can be a depressing month. It’s cold or wet depending where you live, the days are still a bit short, and the summer still seems an awfully long way away. You console yourself by booking a ticket to a hacker camp, but the seven months or so you’ll have to wait seems interminable.

If you want an interesting project to look forward to, take a look at [Benadski]’s idea for a decentralised low voltage local DC power grid for the upcoming SHA 2017 hacker camp in the Netherlands. The idea is to create a network that is both safe and open for hacking, allowing those with an interest in personal power generation to both have an available low-voltage power source and share their surplus power with other attendees.

The voltage is quoted as being 42V DC +/- 15%, which keeps it safely under the 50V limit set by the European Low Voltage Directive. Individuals can request a single 4A connection to the system, and villages can have a pair of 16A connections, which should supply enough for most needs. Users will need to provide their own inverters to connect their 5V or 12V appliances, fortunately a market served by numerous modules from your favourite Far Eastern sales portal.

This project will never be the solution to all power distribution needs, but to be fair that is probably not the intention. It does however provide a platform for experimentation, collaboration, and data gathering for those interested in the field, and since it is intended to make an appearance at future hacker camps there should be the opportunity for all that built up expertise to make it better over time.

We’ve touched on this subject before here at Hackaday, with our look at the availability of standard low voltage DC domestic connectors.

Wind turbine image: Glogger (CC BY-SA 3.0) via Wikimedia Commons.

New Caps And RAM Save Another Poly-1

1980s American teenagers, if they were lucky enough to attend a school with a computer lab, would have sat down in front of Apple IIs or maybe Commodore VIC20s. Similarly, their British cousins had BBC Micros. Solid and educational machines with all sorts of wholesome software, which of course the kids absolutely preferred to run in preference to playing computer games.

New Zealanders, at least a few of them, had the Poly-1. A footnote in the 8-bit microcomputer story, this was a home-grown computer with a built-in monitor clad in a futuristic one-piece plastic shell. Non-Kiwis never had the chance to encounter its 6809 processor and 64k of RAM, the global computer business being too great a challenge for a small New Zealand technology company, especially one whose government support had evaporated.

Decades after the end of Poly-1 production, some survive in the hands of enthusiasts. [Terry Stewart] has two of them, and has posted details of how he brought life back to one that was dead on arrival. It’s a story first of a failed electrolytic capacitor and tricky-to-dismantle PSU design, then of an almost-working computer whose random crashes were eventually traced to a faulty RAM chip. It seems swapping out that quantity of DIL RAM chips is rather tedious, and of course it had to be the final chip in the final bank that exhibited the problem.

Meanwhile it’s interesting to see the design of this unusual machine. A linear power supply contrasts with the switcher you’d have found in an Apple II at the time, and the motherboard is a huge affair. it’s easy to see why this was a relatively expensive machine.

We brought you [Terry]’s first Poly-1 last year, but so far he’s the only owner whose machine we’ve seen. More mainstream 8-bit machines are a common sight here, so for something else a bit esoteric read our coverage of home computers behind the Iron Curtain, and its companion piece on peripherals behind the Iron Curtain.

[via Hacker News]

Understanding The Quartz Crystal Resonator

Accurate timing is one of the most basic requirements for so much of the technology we take for granted, yet how many of us pause to consider the component that enables us to have it? The quartz crystal is our go-to standard when we need an affordable, known, and stable clock frequency for our microprocessors and other digital circuits. Perhaps it’s time we took a closer look at it.

The first electronic oscillators at radio frequencies relied on the electrical properties of tuned circuits featuring inductors and capacitors to keep them on-frequency. Tuned circuits are cheap and easy to produce, however their frequency stability is extremely affected by external factors such as temperature and vibration. Thus an RF oscillator using a tuned circuit can drift by many kHz over the period of its operation, and its timing can not be relied upon. Long before accurate timing was needed for computers, the radio transmitters of the 1920s and 1930s needed to stay on frequency, and considerable effort had to be maintained to keep a tuned-circuit transmitter on-target. The quartz crystal was waiting to swoop in and save us this effort.

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