linux

653 Articles

A $1, Linux-Capable, Hand-Solderable Processor

September 17, 2018 by 87 Comments

Over on the EEVblog, someone noticed an interesting chip that’s been apparently flying under our radar for a while. This is an ARM processor capable of running Linux. It’s hand-solderable in a TQFP package, has a built-in Mali GPU, support for a touch panel, and has support for 512MB of DDR3. If you do it right, this will get you into the territory of a BeagleBone or a Raspberry Pi Zero, on a board that’s whatever form factor you can imagine. Here’s the best part: you can get this part for $1 USD in large-ish quantities. A cursory glance at the usual online retailers tells me you can get this part in quantity one for under $3. This is interesting, to say the least.

The chip in question, the Allwinner A13, is a 1GHz ARM Cortex-A8 processor. While it’s not much, it is a chip that can run Linux in a hand-solderable package. There is no HDMI support, you’ll need to add some more chips (that are probably in a BGA package), but, hey, it’s only a dollar.

If you’d like to prototype with this chip, the best options right now are a few boards from Olimex, and a System on Module from the same company. That SoM is an interesting bit of kit, allowing anyone to connect a power supply, load an SD card, and get this chip doing something.

Currently, there aren’t really any good solutions for a cheap Linux system you can build at home, with hand-solderable chips. Yes, you could put Linux on an ATMega, but that’s the worst PC ever. A better option is the Octavo OSD335x SoC, better known as ‘the BeagleBone on a Chip’. This is a BGA chip, but the layout isn’t too bad, and it can be assembled using a $12 toaster oven. The problem with this chip is the price; at quantity 1000, it’s a $25 chip. At quantity one, it’s a $40 chip. NXP’s i.MX6 chips have great software support, but they’re $30 chips, and you’ll need some DDR to make it do something useful, and that doesn’t even touch the fiddlyness of a 600-ball package

While the Allwinner A13 beats all the other options on price and solderability, it should be noted that like all of these random Linux-capable SoCs, the software is a mess. There is a reason those ‘Raspberry Pi killers’ haven’t yet killed the Raspberry Pi, and it’s because the Allwinner chips don’t have documentation and let’s repeat that for emphasis: the software is a mess.

Still, if you’re looking for a cheap chip you can solder at home, this one seems to be the only game in town. We’re really looking forward to seeing what you make with it!

Linux, Without The Git Factor

September 17, 2018 by 82 Comments

Linux started as a student project in the 1990s, the creation of Linus Torvalds. He has attained celebrity status while steering his creation through the decades, but along the way he has also attracted a different reputation within the Linux and software community. He is famous for his outbursts and rants, some of which become rather personal, and it is not difficult at all to find kernel developers or would-be kernel developers who have turned their backs on the project as a result.

It’s very refreshing indeed then to read an update from [Linus] as part of his regular communications, in which he admits that he has an issue, and says that he is taking the time to seek help for it. There is an accompanying update to the kernel maintenance code of conduct, which suggests that this is likely to mark a sea-change in that environment, as well as we hope salvage that aspect of [Linus]’ reputation.

“My flippant attacks in emails have been both unprofessional and uncalled for. Especially at times when I made it personal. In my quest for a better patch, this made sense to me. I know now this was not OK and I am truly sorry.”

The Hackaday community has a much greater than average proportion of Linux users among its readership. Even those readers who use a desktop OS with BSD, Windows, or other kernels will almost certainly have a Linux kernel somewhere, whether it’s in their phone, their set-top-box, their children’s toys, or even their domestic appliances. And of course a large swath of the Internet runs on Linux. It is in the best interest of us all that we continually attract and retain brilliant people to contribute to the effort put into developing and maintaining the Linux kernel.

Without wishing to lionise [Linus] above the many others whose work has also contributed to Linux and its success, his contribution to our community has been beyond measure and it has been uncomfortable to see his other side. It’s a step in the right direction to apologize for personal attacks and behavior that drives a wedge into the kernel developer community, and seek to change that behavior. We’d urge others to follow his example, we’re sure every grouping has at times had its personality problems, and it’s never too late to enact some repairs.

While Linus steps away to work on his self improvement, veteran kernel developer Greg Kroah-Hartman will take the reigns among the kernel maintainers.

$99 Pinebook Gets KDE Neon Port

August 29, 2018 by 42 Comments

If you’re the kind of person who likes small and cheap Linux devices, you’re definitely alive in the perfect moment in history. It seems as if every few months we’ve got another tiny Linux board competing for our pocket change, all desperate to try to dethrone the Raspberry Pi which has already set the price bar exceptionally high (or low, as the case may be). We’ve even started to see these Linux boards work their way into appropriately cheap laptops, though so far none have really made that great of an impression.

But thanks to the efforts of Blue Systems and Pine64, the situation might be improving: they’ve worked together on a build of KDE Neon for the $99 Pinebook. The fact that they’ve gotten Plasma, KDE’s modern desktop environment, running on the rather mediocre hardware at all is an accomplishment by itself. But they’ve also set out tailor the entire system for the Pinebook, from the kernel and graphics drivers all the way up to Qt and Plasma tweaks.

In a blog post announcing the release candidate of the OS, Neon developer [Jonathan Riddell] says that these top-to-bottom improvements show that you can turn a super cheap Linux laptop into a practical computer if you’re willing to really get in there and optimize it. He also says the project has been something of a two-way street, in that improvements made for the Pinebook build have also been applied to upstream development.

The last time we looked at the Pinebook, we came away cautiously optimistic. It wasn’t great, but it was about as good as you could possibly expect given the price. If more developers are willing to go out on a limb and start optimizing their software for the device, it might become a very promising platform for low-cost mobile hacking.

Linux Fu: Modernize Your Command Line

August 29, 2018 by 19 Comments

If you use Linux and its associated tools on the desktop or on a Raspberry Pi, or on a server, you probably have used the command line. Some people love it and some people hate it. However, many of us have been using Linux for years and sometimes Unix before that, and we tend to use the same old tried-and-true tools. [Remy Sharp] had a recent post talking about how he had created aliases to replace those old tools with great modern replacements and it is definitely worth a read.

We’ll be honest, when we first saw the post we almost skipped reading it. A lot of Linux tip posts are pretty uninteresting unless you are a total beginner. But [Remy] has a lot of really great tools and how he has them installed including bat, which is like cat but with syntax coloring (see picture above), and fzf — a command line history search on steroids. He even shows how to join fzf and bat to make a very cool file browser from the command line (see below).

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Run A Linux Terminal On Cheap E-Ink Displays

August 14, 2018 by 49 Comments

If you haven’t kept up with the world of e-ink displays, here’s some good news: they are pretty cheap now. For as little as $15 you can get a small e-ink display that has good enough performance and contrast to actually do something useful. There’s only one problem: figuring out how to drive them in your project.

Tired of seeing nothing but wiring diagrams and sample code when it came to actually putting these e-ink modules to use, [Jouko Strömmer] decided to try his hand at creating a turn-key application for these gorgeous little displays. The result is PaperTTY, a Python program that allows the user to open up a fully functional Linux virtual terminal on an e-ink display.

Of course, there are some caveats. For one, this all assumes you’re using a Waveshare display (specifically their 2.13 inch HAT) connected to a Raspberry Pi over SPI. Not to say that’s the only hardware combination that will work, but it’s the only one that [Jouko] has done any testing on at this point. If you want to try to shake things up in terms of hardware, you might need to get your hands dirty.

The advantage of being able to open a Linux VT on one of these e-ink displays is pretty simple: you can run basically any piece of software you want on it. Rather than having to come up with software that specifically features support for the display, you can just use (or write) standard Linux console programs. [Jouko] mentions a number of popular programs such as vim and irssi, but you could just as easily write a Bash script to dump whatever data you like to the screen.

In the video after the break [Jouko] shows PaperTTY in action for the doubters who think these sorts of displays are no good for interactive use. The display is very crisp and readable, with no signs of flickering. Overall he says the experience is not unlike using a slow SSH connection. It might not be how we’d like to use a computer full time, but we can definitely see the potential.

With the recent progress with Kindle hacking, it seems that interest in e-ink is as high as ever. Despite what the haters might claim, it’s a useful niche tech that still holds plenty of promise.

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Beginning BLE Experiments And Making Everything Better

August 3, 2018 by 15 Comments

Successfully connecting things without physical wires has a profound effect on the maker brain. Machines talking to each other without any cables is as amazing today as it was a decade ago. When Bluetooth came out, it was a breakthrough since it offered a wireless way to connect cellphones to a PC. But Bluetooth is a complicated, high-bandwidth power hog, and it didn’t make sense for battery-powered devices with less demanding throughput requirements to pay the energy price. Enter Bluetooth LE (BLE), with power requirements modest enough to enable a multitude of applications including low power sensor nodes and beacons.

Over the years, a number of gadgets with BLE have popped up such as the LightBlue Bean, BLE Beacons as well as quadcopters like the FlexBot that rely on BLE for communication. Android or iOS apps are the predominant method of talking to these wonderful gadgets though there are alternatives.

This is the first in a two part series on building with BLE devices. First, I’ll survey some BLE devices and how to get started with BLE from the Linux command line. Later, we will go into describing the process of making a NodeJS cross-platform app that will leverage the BLE capabilities and connect it to the Internet.
Lets get started.
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Linux Fu: Scripting For Binary Files

June 29, 2018 by 31 Comments

If you ever need to write a binary file from a traditional language like C, it isn’t all that hard to do. About the worst thing you might have to deal with is attempts to fake line endings across Windows and Linux, but there’s usually a way to turn that off if it is on by default. However, if you are using some type of scripting language, binary file support might be a bit more difficult. One answer is to use a tool like xxd or t2b (text-to-binary) to handle the details. You can find the code for t2b on GitHub including prebuilt binaries for many platforms. You should be able to install xxd from your system repository.

These tools take very different approaches. You might be familiar with tools like od or hexdump for producing readable representations of binary files. The xxd tool can actually do the same thing — although it is not as flexible. What xxd can even reverse itself so that it can rebuild a binary file from a hex dump it creates (something other tools can’t do). The t2b tool takes a much different approach. You issue commands to it that causes it to write an original hex file.

Both of these approaches have some merit. If you are editing a binary file in a scripting language, xxd makes perfect sense. You can convert the file to text, process it, and then roll it back to binary using one program. On the other hand, if you are creating a binary file from scratch, the t2b program has some advantages, too.

I decided to write a few test scripts using bash to show how it all works. These aren’t production scripts so they won’t be as hardened as they could be, but there is no reason they couldn’t be made as robust as you were willing to make them.

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