Inhoudsopgave van May 2018 - Linux Format

Jonni Bidwell I’d like a robot to write some questions for the recently reprised Answers section. Come to think of it, I’d like another robot to answer those questions too, because I have enough Linux problems of my own. And you know what? I rather miss my DiddyBorg robot. How come I don’t get fun hardware to play with anymore? Sean D Conway A husbandry pibot that could feed the dog. Sounds simple enough in theory. The pibot would have to be a doppelganger of me for it to work, mind. The animal has imprinted on me as her only source of food and refuses to acknowledge anyone else. That’s loyalty for you. Matthew Hanson I’ve been eyeing up one of those robot vacuum cleaners with envy. Anything that can…

At this year’s Mobile World Congress (MWC) in Barcelona, Jolla announced Sailfish 3, the latest version of its alternative to Android. While Android remains the operating system of choice for smartphones, that hasn’t dissuaded Jolla. On its website announcing the new version (https://jolla.com/sailfish3/), Jolla looks back at the journey so far, beginning with MeeGo, the Linux-based predecessor of Sailfish OS that at one point powered many of the world’s Nokia handsets. Despite not making significant headway in the world of smartphone operating systems, Jolla is positioning Sailfish 3 for cheaper, less-powerful smartphones. Jolla CEO Sami Pienimaki says its main aim is to function with “low-spec hardware configurations and still run selected Android apps.” This makes it a direct rival of Google’s lightweight Android Go operating system. Sailfish 3 is set…

“There’s a world of difference between supporting a Linux desktop in a business environment, and maintaining a server in that environment. Some desktop users favour being on the edge, having the latest software and favouring rolling release distros. In contrast, servers benefit from stability, and perhaps you install Long Term Support (LTS) distros, such as the even-year April releases of Ubuntu. I don’t think either extreme is ideal. The rolling releases are hard to support: anything can change at any time, and things do break. Maybe the person using the workstation is capable of sorting out the odd glitch themselves, but even if that’s the case there are better things for them to do with their working day. Only a subset of the distribution’s packages are supported under LTS. For…

The open source Signal app (https://signal.org ) has become a popular alternative to WhatsApp and Facebook Messenger, enabling people to communicate freely without privacy concerns, and it’s now launched the Signal Foundation, a non-profit organisation that will help continue Signal’s work. This has come about thanks in part to the help of WhatsApp co-founder Brian Acton, who has personally donated $50 million to help create the foundation. In the press release (which can be read at https://signal.org/blog/signal-foundation), the team explains how this will help the Signal project. “We can now increase the size of our team, our capacity, and our ambitions. This means reduced uncertainty on the path to sustainability, and the strengthening of our longterm goals and values. The addition of Brian brings an incredibly talented engineer and visionary…

Have I got news for you? Q It’s hard to find a good RSS reader nowadays. Liferea works, but looks a little dated. It seems like every other client has its own quirks and niggles. There are lots of hosted services, many of which are inferior to the once ever-so-popular, now shuttered Google Reader service. Feedly is popular, but if I’m going to use a hosted service I’d rather it’d be one that I hosted myself. I’ve recently upgraded my Nextcloud instance to 13.0 and thought I’d try its News app. It works very well, I can use the Android app to check feeds on my phone, and I can use Feedreader on my desktop. However, I’m seeing this strange error in the News app itself: Non UTF-8 charset for…

HOW WE TESTED… Unlike desktop distributions that require extensive RAM and graphic cards for optimum performance, a NAS box requires little more than ample storage space. The off-the-shelf solutions sold by manufacturers typically feature a two- or four-disk setup and we’ve got the same for our distributions, with 4GB RAM. The distributions are all fairly simple to install, but it’s the post-install configuration that’s the real test, coupled with the ability to provide additional functionality through addons. Most NAS distributions provide an easy-to-navigate web-based administration interface, but we still want it to be intuitive. Because a NAS system is primarily concerned with data, we’ll keep an eye out for associated capabilities such as data encryption. Since the idea is to share disks across different devices, we want our NAS solution…

While NAS is traditionally used for creating a central storage repository, our chosen NAS distributions can be tweaked to take on much greater responsibility. You can turn them into a media streaming system for instance, or add an anti-virus to test the integrity of the stored data. Because these distributions don’t feature a graphical desktop environment, your only choices are to either configure everything by hand from the shell, or use the web-based administrative interface. As important as all the other features are, we also don’t want a distribution that’s impossible to work with because of its unintuitive interface. We also don’t want the interface to be so simplistic that it doesn’t make it possible for you to adjust any settings. EasyNAS 4/10 Once installed, you’re dropped into a shell…

We’ve covered the top NAS solutions in this Roundup. There’s a long list of dormant NAS solutions that we can’t recommend because they haven’t been updated in quite a while. Besides the open source solutions, there are some commercial ones as well. Most charge for their enterprise-specific features, while some charge for support and other conveniences. There’s the unRAID Server, which is available as a USB image. You can try it for free for 30 days after which you’ll have to purchase a license that start with $59 (about £43) and allow attaching up to six storage devices. Open-E DSS V7, which is replete with Enterprise-specific features, also offers a 60-day free trial. Then there’s Server Elements that has three NAS products that run entirely from RAM. NASLite-2 is a…

We’ll concentrate on bread-and-butter software, namely Raspbian and Python, but there are a number of interesting platforms than can be run on top of, alongside or instead of these. One such platform is Robot OS (ROS, see www.ros.org) which isn’t really an operating system at all, but more of a middleware. ROS is a BSD-licensed project with thousands of contributors worldwide. It can be built from source for Raspbian, but since it provides packages for the Pi edition of Ubuntu MATE, that’s the preferred base. ROS aims to be truly general-purpose robot software that works on many platforms and encourages collaboration. We’re also impressed with the work of Dexter Industries (www.dexterindustries.com), which makes the GoPiGo robot car. The GoPiGo is a kit designed for the classroom, and is programmed using…

So far we’ve managed to keep our feet/wheels/ caterpillar tracks on the ground, but we think we should finish our robotic journey with a brief foray into the world of drones. Keeping a drone in the air is a complicated business. Each motor has to be able to respond as close to instantly to changes in orientation. These are detected by a three-axis accelerometer. Other instrumentation is required, too: gyroscopes, servos, and of course motors to keep the propellers turning and generate lift. A vanilla Linux Kernel isn’t built to respond within such operational deadlines as this, so it’s common for drones to run a real-time OS (RTOS) such as NuttX, or indeed a proprietary OS. The Linux kernel can be tweaked to get closer to such response times though.…

Computers have been winning against meatbag chess players ever since Deep Blue beat Kasparov in the 90s. But at the end of 2017 we saw headlines about Google’s deep learning engine AlphaZero ‘teaching itself to play chess’ in four hours, and then beating Stockfish, the world’s best chess engine (see www.chess.com/news/view/google-s-alphazero-destroys-stockfish-in-100-game-match). This training took place on some of the most advanced hardware in the world, and probably equates to many years on commodity hardware. So we shouldn’t read too much into that four hours. What’s interesting is the style of play demonstrated by AlphaZero. In the ten games made public (https://deepmind.com/research/alphago/alphazero-resources) it seemed to show no concern for sacrificing material, if there was a possibility of a trade-off, and in some cases played moves that appeared to make no sense.…

As I write this I’m sat at the start of a weekend of celebrations for the Raspberry Pi’s sixth birthday. This weekend Preston Raspberry Jam along with many others around the world will be celebrating the success that started back in 2012. The Raspberry Pi may be from Cambridge, but the Jam community started in England’s north west – some say Preston, some Manchester, but they both started from humble roots. At the start there were very few Raspberry Pis and not much information was out there to help users. The Jams gave enthusiasts the time and access to the kit, enough for them to develop projects, blogs and documents that have gone on to become de facto standards. I was present at both of the first Jams. Preston was…

OUR EXPERT Les Pounder is a freelance maker who works with organisations such as the Raspberry Pi Foundation to promote maker skills. He blogs at www.bigl.es. YOU NEED A Raspberry Pi 3 or 3 B+ An Internet connection A USB flash drive or USB hard drive Keyboard, Mouse and Screen for your Pi A 2.5A official power supply Another computer running Linux or Windows To celebrate the release of the new Raspberry Pi 3 B+ we’ll use it to create our own Samba server to store files and media for access across our home network. We’ll then use the same Pi to block ads and create a better browsing experience. Samba file server Let’s make sure that we have the latest version of Raspbian. Download this from the Raspberry Pi…

Like putting the necessities in a suitcase for a trip abroad, the same can be said of putting the necessities in a Pi configuration. The first step for all things Raspberry Pi is to consult the www.raspberrypi.org site. At www.raspberrypi.org/documentation/installation/installing-images documents there are instructions that are relevant to the installation of current operating system (OS). With the OS installed, there are a few raspi-config options that can be applied to tailor the configuration. These include expanding the file system to take advantage of the larger memory cards being used, personalising the device by giving it a hostname and tweaking options to accommodate what side of the Atlantic the Pi resides on. Access the command line interface (CLI) by turning on SSH and turning off a GUI. A final touch is…

OUR EXPERT Shashank Sharma is a trial lawyer in Delhi and avid Arch Linux user. He’s always on the lookout for geeky memorabilia. Unless you’re very, very organised, you’re unlikely to be able to accurately describe the amount of time you spend on any given task performed over any given period. Keeping careful track of the amount of time spent on a task becomes a priority if you plan to bill clients on an hourly basis. A time-tracking app can be used to help make sense of how you spend the hours at work. This data can help you identify areas where you need to increase your productivity. You might realise you’re taking rather long lunches or spending too much time on research, and not enough responding to emails (although…

When your project expands, there may be many users helping out with the same code or even different code. In such cases, you may want to share computing power across all the machines that you, your friends and colleagues use. After all, you only use the entire processing power of your computer when you compile, render graphics and play graphic-heavy games. Since you’re already using distcc, the simplest solution is to install DMUCS (distributed multi-user compilation). When you configure the system you put in all the hosts, make sure they can run distcc and set priority parameters according to the processing power of the node. The system is designed so that many users can compile simultaneously, while it scales well to handle the different loads. It also makes use of…

You own the data rights, possess the data and administration responsibility. Only you and trusted off-site partners possess your data, while only you can decrypt it. You pay no costs to operate or subscribe. Synchronisation occurs without third-party relays. All you need is to find a friend with spare disk space and an internet connection. Backups occur based on specific events (changing a file) and time (every so often). Off-site backup scales to your needs. Data is encrypted outside of your local network and at rest. The architecture is suitable for remotely stored data, not real-time random access of remote data. No additional file viewers, slideshow viewers or music software that age quickly. No tangential database or computer language requirements such as installing MySQL, PHP, web servers and so on.…

OUR EXPERT Tim Armstrong is the network and systems architect at Nerdalize. He specialises in design and implementation of cloud environments and ISP Networks. For this tutorial we’re going to take live data that we’re collecting from TheThingsNetwork and present it in a simple website. To build our website we’ll be using Node-RED, which is an excellent flow-based graphical programming language. You drag nodes that represent inputs, functions and outputs into a flow that can be deployed as a service on anything from a Raspberry Pi to a cloud platform. Previously in LXF235 we built a simple sensor that measured the voltage across a light-dependant resistor (LDR) and sends that data over LoRa to TheThingsNetwork (TTN). This circuit design can be applied to most analog sensors (and even some microphones)…

OUR EXPERT Dr Sinitsyn is a lapsed KDE committer with 0.16 Google pupils per year, so he time to build Linux clouds and write articles. Peeking into running production systems is much like changing tyres on a moving car: possible yet rather non-trivial. Back in LXF231, we looked at eBPF, which enables you to carry out a system-wide inspection and profiling session that’s both safe and fast. We also told you that eBPF is conceptually a successor to DTrace, a Solaris technology that debuted in the early 2000s. That issue, we also told you that Oracle is silently shutting down Solaris, and not to expect any more news from that camp. Well, that last bit was apparently a bit wrong… When Sun Microsystems open-sourced most of Solaris, including ZFS and…

OUR EXPERT Mihalis Tsoukalos is a UNIX administrator, a programmer, a DBA and a mathematician. You can reach him at www.mtsoukalos.eu. These days, machine learning (ML) is not only important as a research area of computer science, but it’s also started playing a key role in our everyday lives. As if this wasn’t enough, an exponential growth in the usage of ML is expected in the next few years. The biggest advantage of ML is that it offers new and unique ways of thinking about the problems we want to study and solve. ML is all about extracting knowledge from your data using a computer – in this case, all the examples of this tutorial are going to be written in Python 3. However, the topic is huge and can’t…

OUR EXPERT Kent Elchuk builds and maintains custom apps for various institutions and has an abundance of web authorship. We’re going to look at building a custom Wordpress theme using any basic website template or bare bones css responsive framework such as Bootstrap. Although all of the steps will be explained, this procedure will be much easier for those who have basic HTML and responsive design skills. This article should come in handy for anybody who wants to convert an existing static website (or almost any other website for that matter) to Wordpress. Because Wordpress is free, you’ll have complete ownership of the site, and can even host it on your own home network for free. And since it dominates the CMS (Content Management System) market, learning how to create…

This month, I’ve been doing battle with GRUB. In the good old days, a five-line config file was enough to boot a Linux distro. Now we have the massive GRUB2 with config files more than 100 lines long, full of module loading and conditional statements. GRUB2 is better suited to automatic generation of its menus, which makes it ideal for distro installers. However, hand-crafting menus is nowhere as easy as it was. RTFM I hear you cry! Well, the documentation is quite lengthy, but still lacking in information at times. It’s a classic situation of a program becoming more powerful, yet getting more complex in the process, while the documentation struggles to keep pace. Unlike Marmite, I find myself able to love and hate it at the same time, especially…

PROGRAMMING FROM THE GROUND UP This is an introduction to programming, but it differs from most introductory texts in one important respect: the choice of language. Most programming introductions either use C because it’s ubiquitous, or they use a language that’s easy to get to grips with, simple to debug and forgiving of newbie mistakes, such as Python. This book uses a language that’s none of those: assembly. While it may seem an odd choice for a programming introduction, assembly does provide a pure access to the system and any lessons learned here will stay with you should you decide to later use a compiled or interpreted language. READING MATTER Bookshelf Advanced Bash Scripting Guide Go further with shell scripting. Bash Guide for Beginners Get to grips with the basics…

Quantum computing You don’t need a super-cooled, underground lab to run quantum experiments. We reveal how to get started. Get a better CMS Open source runs the web, so we check out content management systems and tell you which one is best! Contain this! The Linux world is going container crazy! This exciting new technology goes under the LXF microscope. Classic computing Relive your heady Atari ST days as we take an in-depth look at open source Atari and TOS emulation. Contents of future issues subject to change – we might be too busy reformatting our drives (again).…

If you’re wondering if things are looking a little different around here, don’t worry, you’re not going mad. After 152 issues and almost 12 years (October 2006) Linux FormatTowers has finally been able to afford a fresh lick of paint, but don’t panic! All your favourite sections remain intact and as they were. They’re hopefully just easier to read for everyone! And the good news keeps on coming, because we have a double whammy of Raspberry Pi content this issue. First there’s the lowdown on the new Raspberry Pi 3 B+. Then there’s our lead feature on building, much like the Pi itself, all-conquering Pi robots! It feels like the Raspberry Pi Foundation has got into the swing of releasing these Pi boards, which is great. We now have a…

Fans of Chromebooks who aren’t too keen on the limitations of Chrome OS will be pleased to hear that Chrome OS may soon get the ability to run Linux applications. While Chrome OS is based on Gentoo Linux, it’s limited to running apps from the Chrome web store. The operating system had a recent boost with the ability to run Android apps, but with full Linux applications apparently coming, our Chromebooks could become even more useful. A new commit on the Chromium Gerrit (a web-based code collaboration tool for the operating system that can be found at https://chromium-review.googlesource.com/q/status:open), has been discovered. It’s called “New device policy to allow Linux VMs on Chrome OS,” which adds a new menu, called Better Together. This looks like it’ll enable Linux containers to be…

The project that’s bringing LibreOffice to the web has just received a big update. Collabora Online (www.collaboraoffice.com) is an exciting project that offers a LibreOffice-powered online office suite to rival Google Docs, and it recently received a major update that makes it even more competitive. The three major programs of LibreOffice – the Writer word processor, Calc spreadsheet application and Impress slideshow editor – have all been given new features in line with the project’s road map. These are geared at making the online office suite as functional and easy to use as the standard version. Users of Collabora Online 3.0 can view and edit documents through a web browser, and all data can be stored either on-premise or in the cloud. Michael Meeks, general manager of Collabora Productivity is…

FIREFOX 59.0 The popular open source web browser received a brand new engine – Quantum – last year. Yet development work hasn’t slowed down, with the latest release continuing to focus on performance gains as well as adding more features. So, we’re getting improved page load times, improved graphics rendering, new tools for annotating and editing screenshots, and improvements to how Top Sites is arranged on the Home page. For more information on what’s new, head over to www.mozilla.org/en-US/firefox/59.0/releasenotes. ZORIN OS 12.3 This Ubuntu-based distro aimed at beginners has recently been updated, and it now comes with Wine 3.0, which enables Windows programs to run on the distribution. This is an excellent addition for helping new users make the switch from Microsoft’s OS to Linux, and Wine 3.0 not only…

FedoraEDU I’ve been reading about the “Endless” OS, a Linux-based OS that requires no or limited internet access. It’s designed for the educational market and home use. It has offline Wikipedia access, a library of e-textbooks, and all the apps you’ll ever need. I think it should have competition. I propose that there should be a “spin” of Fedora, that requires to be of a longer term than the typical Fedora life cycle. Why not include offline Wikipedia access, and why not offer a library of e-textbooks on computer-related subjects to the English language? FedoraEDU, as I call it, would help schools and universities offer an alternative to Windows or Mac-based OSes. It has the potential to be an incredible tool for poor students striving toward higher academic goals. Markus…

Who’s afraid of the big, bad IronWolf in this age of super-sized, super-fast SSDs, Jeremy Laird asks? These days, performance storage is all about solid state. SSDs provide not only by far the fastest performance, they now also offer the largest capacities hitting 30TB – for a price. Yet there’s one metric that remains dominated by old-school magnetic hard drives: storage bang for buck. If you want maximum storage density for the minimum possible price then you’ll need some spinning magnetic platters. With that in mind, it’s no surprise to find that conventional hard drive technology marches on despite its relegation to a mere commodity product. A little over a year ago, the biggest mainstream hard drives weighed in at 10TB. Now we’re reviewing our first 12TB drive, the Seagate…

Unlike desktop distributions where you can find your way around the system through simple trial and error, a NAS setup doesn’t take kindly to such cavalier poking about. Unless you know what you’re doing, you’re very likely to break your NAS setup and render it useless. FreeNAS, one of the most beloved NAS projects, is a behemoth of information. It’s safe to say that when it comes to documentation, FreeNAS is to NAS distributions what Arch and Gentoo are to Linux. Apart from the community forums and IRC channel that you can use to find answers to specific problems, the projects hosts extensive documentation on its website. In addition to a public forum board, the EasyNAS project provides some basic information and quick introduction to important concepts and technologies such…

Hosting your own NAS requires more than mere installation of the underlying distribution and tweaking a few settings. You also have to consider other factors such as the update policy for the distribution. This is especially important because NAS distributions don’t feature a graphical desktop environment. With EasyNAS, you can easily schedule automated backups of added volumes. Unfortunately, it lacks some of the more advanced features and can’t hook up with a directory server, for instance. And while the distribution supports many different protocols and services, you’re unable to configure any of them. However, users are able to run a simple web server, making it possible to look at and download files from a web browser. The oldest and most beloved of the NAS distributions, FreeNAS can be easily extended…

Robotics needn’t be about building intimidating humanoid automatons. We can build machines that can perform all kinds of other useful, instructive or fun functions. Even better, you can power them with Linux. You won’t need costly electronics to build these devices. A Raspberry Pi will do just fine. It doesn’t need to be any more advanced than constructing a LEGO set, either. There are plenty of off-the-shelf kits suitable for any budding electronics enthusiast. We’ll reveal how to put together your own roving robot, and show you a couple of neat Python programs to get you started. And if you’re feeling more adventurous, then why not build your own robotic helpers from scratch? All the components are easy to get hold of, thanks to the growing maker community. If you…

Spend much time around tech companies and initiatives in Africa and it’s hard not to be infected by the constant upbeat enthusiasm for the potential of tech on the continent. Whether the challenge is government accountability, the rule of law, business practices or education, the vision expressed by activists, corporate workers and politicians alike is that digital technologies will leapfrog centuries of under investment in infrastructure, just like mobile phones did for the communications network. Some of this is typical Silicon Valley techno-evangelism, and cynics can rightly point out that many of the solutions being offered to help solve social issues across the continent are also handy ways for US-based megacorporations to find new customers and profit streams. It’s a stance summed up in the title of Noam Cohen’s new…

Samba is easy to set up and it works across operating systems. It can also be used to share printers over a network using the CUPS service. CUPS is easy to install and in LXF228 we covered how to install CUPS on a Pi Zero W and convert an old inkjet printer into a wireless printer. NFS also offers benefits for Linux users. Chief of these is that a user’s Home directory can be served over the network via NFS – handy for thin client devices, while storage devices such as optical drives can be accessed as if the user is sat at that remote machine. Installing NFS is simple, and there’s a guide at https://help.ubuntu.com/community/SettingUpNFSHowTo that will work with Raspbian. If all of this file server talk has sparked…

The BOARD option is physically consistent, regardless of the board revision of the Raspberry Pi. You won’t need to rewire your connector or change your code if you replace a board. You still need to be aware of which pins you can and can’t use though, because some are power and GND pins. BCM numbers changed between versions of the Pi 1 model. BCM channels moved around a little between revision 1 and revision 2 of the Raspberry Pi board. To accommodate for this change, always work with a pin-out diagram for the Pi to determine which channel number goes to which pin the board. GPIO numbers come in handy when interfacing with other products like Gertboards. In this project the Adrafruit DHT sensor configuration needs GPIO references. A function…

A time tracker is a multi-tasker’s worst enemy. This is because tools like Watson is unable to record activities across different projects at the same time. Of course, you can use multiple tags with a single watson start command, but unfortunately you can’t record two projects simultaneously. You must always remember to stop timing a project with the watson stop command. Alternatively, you can configure Watson to stop recording the current project when you give a fresh watson start command. There are two ways to do this. First, you can run the watson config options.stop_on_start TRUE command. Alternatively, you can run the watson config -e command, which opens the configuration file in the configured editor, and you can add the following lines into it: [options] stop_on_start = TRUE When changing…

There are a number of communities and businesses online that supply compiling power for free and open source projects. In fact, many of them also have businesses that pay big bucks for their proprietary projects to be compiled, but private individuals who use free licenses have a few free projects to choose, too. Usually, you need to store your project on a software site such as github or similar. The service is called Constant Integration and well-known sites include Travis Ci and circleCi. In both cases you can use github to store, add a bit of configuration to your project and both sites will compile for you. Error reports stay on the site for you to investigate and correct until you’ve achieve a successful compile. To get started, log in…

The EncFS reverse mode stores clear text files and uses a virtual mount point to present encrypted translations of the files. On the clear text side (see table on the previous page), Syncthing creates the .stfolder in the clear text directory where real data is stored, so the clear text Syncthing peer group on the bridge computer will always operate whether or not EncFS is presenting encrypted files to the other side. This is okay no matter if the sync root and encfs root are the same or whether one is nested inside the other. For the encrypted side virtual directory, if sync root is below EncFS root and EncFS stops, then the sync folder will vanish and you’ll see a “folder missing” error from Syncthing. This could be fine…

So far we’ve looked at an uplink from our device to the cloud, but TTN also provides a handy way to send downlink messages to the device that can be used to trigger an action on the device. To do this, start a new flow and drag in a “ttn downlink” node, give it a name, set the port number to 1, check the confirmed box, provide the device ID, and then set the schedule to last. Then we can simply send that node a bytes array as the msg. payload and it will be received into the receive queue of LoRaMQ. For example, we could add a dashboard switch node and connect it to a function node that would send a byte array to the device when the switch…

Imagine everything you know is contained within a sphere. The more that you know, the greater its radius is. The surface of this sphere touches subjects you’re already aware of, but don’t know yet. When you learn the sphere becomes bigger, but its surface area increases at a faster rate. So the more things you know, the more things you have to study. That was the motivation behind myself taking a Computer Science course in one of the online universities. I learned quite a few things and I liked the course, although not all of it. While the course gave me many insights, it was rather lightweight on why should I do something this way, and not the other way around. This “cookbook-style” teaching is fine, but it loses out…

Version: 3.0 Web: https://github.com/KDE/falkon We love alternative and open source web browsers, especially when they’re good enough to replace Chromium or Firefox for most daily tasks. The abundance of choice is especially important in the modern world, which seems to be dominated by the two titles mentioned above. In issues 212 and 229 we reviewed Qupzilla, a fast and feature-rich web browser that’s been built around QtWebEngine. Realistically, we can’t ignore the world of Chromium clones this time, because QtWebEngine is a repackaged and slightly altered version of the open source Chromium engine (which has been adjusted so it can be used by Qt programs). The name change occurred because of some behind-the-scene developments that resulted in Qupzilla falling under the KDE project umbrella and becoming Falkon. The newly released…

Although you can implement all ML algorithms using almost any programming language, there are many Python 3 modules that can help you work with ML without having to run everything from scratch. The scikit-learn module is built on top of NumPy, SciPy and matplotlib, and offers algorithms for Classification, Regression, Clustering, Model selection, Dimensionality reduction and data Preprocessing. Knowing more about Numpy, matplotlib or Scipy modules with help you, especially if you want to plot any data. The TensorFlow library is also ideal for maths operations such as performing operations with multidimensional arrays as well as vectors and matrices. There’s also a lighter version of TensorFlow called TensorFlow Lite for mobile and embedded devices. You can find more information about TensorFlow Lite at https://github.com/tensorflow/tensorflow/tree/master/tensorflow/contrib/lite. Another popular library is the Keras…

Once you download Wordpress and unzip the file, you can upload and rename the folder to any server where you want the Wordpress site. You can use a hosting account or just build the website on your local web server located on your Linux box. Once you set up the database, open the folder for which the installation takes place, such as localhost/wordpress or http://example.com. Select ‘Run the installation’ and add the database name, username and password. The default prefix is wp_ but you can make it anything you want. On some hosting accounts, this all runs fine. On a home server you may need to edit wp-config-sample.php and add the database name, username and password, then save it as wp-config.php if the server has trouble writing the file. Towards…

“NOW PART OF CORE VULKAN 1.1 IS SUPPORT FOR MULTIPLE GRAPHICS CARDS IN A SINGLE SYSTEM” The Khronos Group (www.khronos.org), the open consortium made up of some of the biggest names in hardware and software, recently announced the release of Vulkan 1.1, the latest version of the cross-platform open source graphics/compute API. This is the first major update to the API since Vulkan 1.0 in 2016, and it coincided with the Games Developers’ Conference (GDC 18) held in March. It also follows the news that Vulkan is now available on Apple’s iOS and macOS platforms. While Apple is still to officially support Vulkan, this news, along with the release of Vulkan 1.1, demonstrates how successful the API is becoming. Along with Apple’s platforms it’s now also available on Linux, Android…

“March saw the launch of three new open source projects focused on low-level firmware and subsystems. This reflects a growing trend of people moving towards open source licensed software for these types of solutions. ACRN is a lightweight, safety-oriented hypervisor project. It’ll provide a framework for industry leaders to build an open source embedded hypervisor specifically for the Internet of Things. Sound Open Firmware, includes a digital signal processing firmware and an SDK that provide tools and infrastructure for developers working on audio or signal processing firmware. Finally, the OpenBMC Project can be described as a Linux distro for embedded devices that have a BMC (Baseband Management Controller). A BMC is found in servers, rack switches or RAID appliances. The OpenBMC stack uses technologies such as Yocto, OpenEmbedded, systemd, and…

The KDE Slimbook II has been released, and this update to the original Slimbook has improved components and a thinner design than its predecessor. The Slimbook II features seventh-generation CPUs from Intel, with a choice of Core i5 and Core i7 configurations, which means it also supports DDR4 RAM, granting it a performance boost over the previous model. Wi-Fi performance has been improved with a new antenna, and there’s an option with a 1TB SSD. It’s also an ounce lighter and a 10th of an inch thinner than the Slimbook. The KDE neon Ubuntu-based distro is preinstalled, and you can find out more at http://kde.slimbook.es. Prices start at £612.…

“Linux’s low-level graphics infrastructure has undergone a quiet revolution, since experimental support for ‘atomic mode-setting’ landed a few years ago. Atomic has two key features: better display control enabling you to change display modes; and userspace use of overlay planes in the display controller for composition, bypassing the GPU. A third, less-heralded, feature is that the core standardises user-visible behaviour. Before atomic, drivers could implement whatever behaviour they liked. The rewrite of the core and a comprehensive test suite means we no longer need hardware-specific drivers to take full advantage of its features. Weston’s DRM backend has now been reworked to take advantage of these. Using atomic gives us a smoother user experience: better performance, lower power use, and is still hardware-agnostic. This has made mainline Linux much more attractive:…

MAIN 300 Guild of Makers launches! With a tagline of “The Maker movement is growing up – the Maker industry is here” you can see that the Guild of Makers is more than just a club. It was created by Dr Lucy Rogers, professional maker, engineer and judge on BBC’s Robot Wars, and fills a void that Lucy herself identified. The identified gap was a membership to a professional organisation that serves the needs of makers from this diverse community. The initial launch of the project took place in late 2017 via a weekly Twitter chat called #makershour and this chat quickly garnered interest from makers, crafters, hackers and tinkerers. The Guild is much more than just a group to support what we traditionally perceive as makers. It aims to…

The upside to a central repository of files is that you can access all your data from virtually any device or machine on the network. The natural downside is that your data is at risk. Security is a key feature for any NAS setup. Apart from using encryption where possible, you must configure robust firewall rules and access control lists to ensure your data isn’t accessible by all and sundry. You must also adopt the strictest security practices such as using HTTPS and using secure data transfer protocols to keep your data safe during transit. It’s good advice to also brush up on SSH best practices if you plan on using that protocol for accessing your data. FreeNAS and NAS4Free are based on FreeBSD. While FreeNAS doesn’t provide many security…

ON WHY BUDGIT BECAME A SUCCESS “Everyone wanted us to scale really fast and to move into different places, because there’s such a big need for this kind of accountability project everywhere” When Bill Gates was invited to South Africa to deliver the 14th Nelson Mandela Annual Lecture at the University of Pretoria in 2016, he spoke long and eloquently about the potential of technology to address pan-continental challenges around energy, job creation, financial inclusion, agriculture and health. He spoke, naturally, about the work funded by the Bill & Melinda Gates Foundation (BMGF) across Africa, and some of the projects he’s seen in his travels. He also name-checked a handful individuals: Mandela and his widow, Graça Machel, his hosts from the university, Steve Jobs and Mark Zuckerberg. And one social…

Formula Pi shifts into the fast lane Prepare to start your Pi-engines, as the 2018 season opens with exciting classes and new race rules. It’s your last chance to take part in the Formula Pi 2018 season! Racing is due to blast off in June, and sign-ups for entry close on 30 April. Formula Pi started life as a Kickstarter project back in July 2016 and it smashed its funding target by 300 per cent. A successful winter 2016 season was followed by a summer 2017 and winter 2017 series, and now 2018’s season is being lined up. The original Grand Pi class has been superseded by the Monster class, a new high-speed limited-entry Raptor class is due to start testing. Find out more and get involved at www.formulapi.com. Pipecam…

When the Raspberry Pi first appeared on the scene in 2012, it came with a unique form factor that had one complaint: poor placement of screw holes. In fact the first version of the board had no screw holes. But why are screw holes important? Well, add-on boards for the Raspberry Pi came in all sorts of shapes and sizes and this caused a few issues for users. For example, the Pibrella board was designed for a 26-pin GPIO and it had a rubber foot to stop it shorting out on the HDMI port when pressed. What was needed was a standard connection, so with the Raspberry Pi B+ in 2014 we saw a 40-pin GPIO and screw holes added to the corners of the board. This offered a consistent…

OUR EXPERT Sean D Conway is a security specialist by day, and is a writer, sports fan and a Raspberry Pi tinkerer once the sun sets.. WARNING! Mains electricity can kill or severely injure. A qualified electrician should be used to connect this project to a mains supply. Switch off and disconnect any equipment before opening, adjusting or testing any part of this project. You undertake this project entirely at your own risk. YOU NEED Raspberry Pi Model B (Rev 2.0) Operating system: Raspbian Jessie Wi-Fi dongle: Ralink Technology, Corp. RT5370 wireless adapter DS3231 clock module 3.3V/5V high accuracy for Raspberry Pi Digital DHT22 AM2302 temperature humidity sensor module for Arduino Solid-state relay SSR-50DA 3-32VDC 50A/250V output 24-380VAC with cover Single-gang drawn handy box 1-7/8 inch deep with 1/2 inch…

During the operation of the unit, a weakness was revealed that required a snow shovel and site visit to resolve. An 8°C difference between the temperature at the unit and the outside temperature occurred when the controller was buried under three feet of snow. Snow can be an insulator, and this resulted in a temperature difference that could switch the AC off when it needed to be on. When the enclosure was dug up and exposed to the outside air, the temperature difference disappeared. It was determined that some additional features would improve the design. A means of overriding the Raspberry Pi at the unit could be used (the device does support a software override). That requires accessing the unit over a network. A momentary switch at the unit would…

OUR EXPERT Mats Tage Axelsson When Mats started with Linux he had an IBM Thinkpad and floppy disks. He still tries to squeeze the maximum out of ageing hardware, the cheapskate! Your day-to-day computer activities usually pass without a hitch, until you fill up your memory and start swapping. And if you’re compiling software or rendering graphics when this happens, then you’ll soon know that something’s amiss. Both activities are memory and CPU intensive, and can take a lot of time to complete. The solution lies in distributed computing, which is the technique of using many computers to do one job. In this article, we’ll focus on how to compile your software projects on your own computers. We’ll also see what solutions animators are using to speed up their workflow.…

OUR EXPERT Brian Mork has used Linux for 23 years since installing Slackware in 1994, and has written dozens of articles on the subject. Cloud file storage are ever-popular these days. However, commercial solutions lack privacy, are insecure, sacrifice control of data, often require installation of invasive software, and force a subscription purchase model on to the consumer. In this two-part series, we’ll discuss an architecture to set up your own free cloud service backup, encrypted both in transit and when data is at rest. You can typically host the backup at a cooperative remote site such as a friend’s house. The software is shareware, and is available for download from the Internet. Hardware requirements include either an old computer you’ve got lying around or a £25 Pi 3 computer,…

The EncFS forward mode stores encrypted files and uses a virtual mount point for clear text translations of the files. On the clear-text side, initially run Syncthing to create the .stfolder in the clear text directories while EncFS is running, so the .stfolder will be propagated into an encrypted file on the left side of the diagram. With sync root and EncFS the same, the .stfolder file will reappear on the clear text side any time EncFS runs, but won’t be present if EncFS isn’t running. This is what we want, and Syncthing will report status “Stopped” if the file isn’t present. With EncFS above sync root, Syncthing will report “folder missing” when EncFS isn’t running. Don’t put the EncFS root below the sync root because then if EncFS isn’t…

IBM Bluemix is easy to get going, but sometimes you just want to run things locally, such as a simple home automation project, which is why Node-RED also works on a Raspberry Pi. Raspbian has made it as simple as possible to get started with Node-RED by pre-installing it as part of the image. You can find it running at http://<The IP of your RaspberryPi>:1880/. To install the extra nodes that we’ve use in the rest of this article simply run the following: If you want to follow this tutorial using your RaspberryPi instead of IBM Bluemix you’ll also need to install couchdb, which you can find the instructions for in the couchdb documentation: http://docs.couchdb.org/en/2.1.1/install/unix.html#debian-based-systems. Then just follow the tutorial starting from the section where we drag in our first…

While “cpu” and “memory” controllers are mentioned in every self-respecting cgroups tutorial, Linux has much more to offer. One popular controller is “blkio”, which limits the number of block I/O requests a process hierarchy can issue. You use it so that large programs reading (or writing) a lot of data don’t starve smaller ones of resources. Two policies exist. The first one is called “proportional weight division” and it’s like a “cpu” controller: you specify weights, and the “blkio” controller divides bandwidth accordingly. Another is “upper limit policy” and it implements throttling if processes in the cgroup exceed a given bytes per second rate for a block device. Another resource is process identifiers (PIDs). If they’re all assigned then you won’t be able to create a process regardless how much…

Data preprocessing is a critical part of ML because wrong or incorrect data will not permit ML algorithms to do their job. So, it’s critical to have your data in the correct format. Two serious questions that often come up when dealing with data are what to do with missing data, and what to do with incorrect data. If a record has missing data, you can either ignore it or fill in the missing data with some default values. However, dealing with incorrect data is much trickier because you’ll need to decide whether to ignore the record with the incorrect data or try to correct it by looking into it in more detail. Generally speaking, if you have lots of data, then ignoring the record with missing and incorrect values…

Categories can be managed by accessing Posts>Categories from the left menu in Admin. We might have one menu item link to a page that displays posts for a given category. In this case, our category is called web-development-and-seo . The slug is from a category. If the web page is a post, it delivers the content. If it isn’t, it gets all posts from the category and displays those titles in a list, linking back to each post. Listing posts for a particular category will look familiar, except the code is modified in index.php because we want to create a rule that separates post content from our chosen category.…