DIY

RV Offsite Backup Update

Kyle Rankin — Wed, 07 Aug 2019 21:15:00 +0000

Having an offsite backup in your RV is great, and after a year of use, I've discovered some ways to make it even better.

Last year I wrote a feature-length article on the data backup system I set up for my RV (see Kyle's "DIY RV Offsite Backup and Media Server" from the June 2018 issue of LJ). If you haven't read that article yet, I recommend checking it out first so you can get details on the system. In summary, I set up a Raspberry Pi media center PC connected to a 12V television in the RV. I connected an 8TB hard drive to that system and synchronized all of my files and media so it acted as a kind of off-site backup. Finally, I set up a script that would attempt to sync over all of those files from my NAS whenever it detected that the RV was on the local network. So here, I provide an update on how that system is working and a few tweaks I've made to it since.

What Works

Overall, the media center has worked well. It's been great to have all of my media with me when I'm on a road trip, and my son appreciates having access to his favorite cartoons. Because the interface is identical to the media center we have at home, there's no learning curve—everything just works. Since the Raspberry Pi is powered off the TV in the RV, you just need to turn on the TV and everything fires up.

It's also been great knowing that I have a good backup of all of my files nearby. Should anything happen to my house or my main NAS, I know that I can just get backups from the RV. Having peace of mind about your important files is valuable, and it's nice knowing in the worst case when my NAS broke, I could just disconnect my USB drive from the RV, connect it to a local system, and be back up and running.

The WiFi booster I set up on the RV also has worked pretty well to increase the range of the Raspberry Pi (and the laptops inside the RV) when on the road. When we get to a campsite that happens to offer WiFi, I just reset the booster and set up a new access point that amplifies the campsite signal for inside the RV. On one trip, I even took it out of the RV and inside a hotel room to boost the weak signal.

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Build a Custom Minimal Linux Distribution from Source, Part II

Petros Koutoupis — Thu, 28 Mar 2019 11:30:00 +0000

by Petros Koutoupis

Follow along with this step-by-step guide to creating your own distribution.

In an article in the June 2018 issue of LJ, I introduced a basic recipe for building your own minimal Linux-based distribution from source code packages. The guide started with the compilation of a cross-compiler toolchain that ran on your host system. Using that cross-compiler, I explained how to build a generic x86-64 target image, and the Linux Journal Operating System (LJOS) was born.

This guide builds on what you learned from Part I, so if you haven't already, be sure to go through those original steps up to the point where you are about to package the target image for distribution.

Glossary

Here's a quick review the terminology from the first part of this series:

Host: the host signifies the very machine on which you'll be doing the vast majority of work, including cross-compiling and installing the target image.
Target: the target is the final cross-compiled operating system that you'll be building from source packages. You'll build it using the cross-compiler on the host machine.
Cross-Compiler: you'll be building and using a cross-compiler to create the target image on the host machine. A cross-compiler is built to run on a host machine, but it's used to compile for an architecture or microprocessor that isn't compatible with the target machine.

Gathering the Packages

To follow along, you'll need the following:

busybox-1.28.3.tar.bz2 (the same package used in Part I).
clfs-embedded-bootscripts-1.0-pre5.tar.bz2 (the same package used in Part I).
Dropbear-2018.76.tar.bz2.
Iana-etc-2.30.tar.bz2.
netplug-1.2.9.2.tar.bz2.
sysstat-12.1.1.tar.gz.

Note: I ended up rebuilding this distribution with the 4.19.1 Linux kernel. If you want to do the same, be sure to install the development package of the OpenSSL libraries on your host machine or else the build will fail. On distributions like Debian or Ubuntu, this package is named libssl-dev.

Fixing Some Boot-Time Errors

After following along with Part I, you will have noticed that during boot time, a couple errors are generated (Figure 1).

Figure 1. Errors generated during the init process of a system boot.

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Weekend Reading: Do-It-Yourself Projects

Carlie Fairchild — Sat, 23 Mar 2019 10:00:00 +0000

by Carlie Fairchild

Join us this weekend as we bring the DIY movement back. Not only is it a chance to start working on those ideas you've been putting off for months, but it's also a great way to learn while playing.

Why You Should Do It Yourself

by Kyle Rankin

Bring back the DIY movement and start with your own Linux servers.

It wasn't very long ago that we lived in a society where it was a given that average people would do things themselves. There was a built-in assumption that you would perform basic repairs on household items, do general maintenance and repairs on your car, mow your lawn, cook your food and patch your clothes. The items around you reflected this assumption with visible and easy-to-access screws, spare buttons sewn on the bottom of shirts and user-replaceable parts. Through the years though, culture has changed toward one more focused on convenience.

Building a Voice-Controlled Front End to IoT Devices

by Michael J. Hammel

Apple, Google and Amazon are taking voice control to the next level. But can voice control be a DIY project? Turns out, it can. And, it isn't as hard as you might think.

This article covers the Jarvis project, a Java application for capturing audio, translating to text, extracting and executing commands and vocally responding to the user. It also explores the programming issues related to integrating these components for programmed results. That means there is no machine learning or neural networks involved. The end goal is to have a selection of key words cause a specific method to be called to perform an action.

Two Portable DIY Retro Gaming Consoles

by Kyle Rankin

A look at Adafruit's PiGRRL Zero vs. Hardkernel's ODROID-GO.

If you enjoy retro gaming, there are so many options, it can be tough to know what to get. The choices range from officially sanctioned systems from Nintendo all the way to homemade RetroPie projects like I've covered in Linux Journal in the past. Of course, those systems are designed to be permanently attached to a TV. But, what if you want to play retro games on the road?

Build a Custom Minimal Linux Distribution from Source

by Petros Koutoupis

Follow along with this step-by-step guide to build your own distribution from source and learn how it installs, loads and runs.

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Two Portable DIY Retro Gaming Consoles

Kyle Rankin — Mon, 03 Sep 2018 12:33:21 +0000

by Kyle Rankin

A look at Adafruit's PiGRRL Zero vs. Hardkernel's ODROID-GO.

But, what if you want to play retro games on the road? Although it's true that you could just connect a gamepad to a laptop and use an emulator, there's something to be said for a console that fits in your pocket like the original Nintendo Game Boy. In this article, I describe two different portable DIY retro gaming projects I've built and compare and contrast their features.

Adafruit PiGRRL Zero

The RetroPie project spawned an incredible number of DIY retro consoles due to how easy and cheap the project made it to build a console out of the widely available and popular Raspberry Pi. Although most of the projects were aimed at home consoles, Adafruit took things a step further and created the PiGRRL project series that combines Raspberry Pis with LCD screens, buttons, batteries and other electronics into a portable RetroPie system that has a similar form factor to the original Game Boy. You buy the kit, print the case and buttons yourself with a 3D printer, and after some soldering, you have a portable console.

The original PiGRRL was based off the Raspberry Pi and was similar in size and shape to the original Game Boy. In the original kit, you also took apart an SNES gamepad, cut the electronics and used it for gamepad electronics. Although you got the benefit of a real SNES gamepad's button feedback, due to that Game Boy form factor, there were no L and R shoulder buttons, and only A and B buttons on the front, so it was aimed at NES and Game Boy games.

The PiGRRL 2 took the original PiGRRL and offered a number of upgrades. First, it was based on the faster Raspberry Pi 2, which could emulate newer systems like the SNES. It also incorporated its own custom gamepad electronics, so you could get A, B, X and Y buttons in the front, plus L and R buttons in the back, while still maintaining the similar Game Boy form factor.

Figure 1. PiGRRL 2

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#geeklife: weBoost 4G-X OTR Review

Kyle Rankin — Tue, 07 Aug 2018 12:00:00 +0000

by Kyle Rankin

Will a cellular booster help me stay connected on my epic working road trip?

I'm a Linux geek, and I think I safely can assume everyone reading an article in Linux Journal identifies themselves as Linux geeks as well. Through the years I've written about many of my geeky projects here in Linux Journal, such as my Linux-powered beer fermentation fridge or my 3D printer that's remotely controlled using a Raspberry Pi and Octoprint software. The thing is, my interests don't stop strictly at Linux, and I doubt yours do either. While my homebrewing, 3D printing and (more recently) RV interests sometimes involve Linux, often they don't, yet my background means I've taken a geek's perspective and approach to all of those interests. I imagine you take a similar approach to your hobbies and side projects, and readers would find some of those stories interesting, useful and inspirational.

We discussed this at Linux Journal and realized there should be a space for Linux geeks to tell their geeky stories even if they don't directly involve Linux. This new series, #geeklife, aims to provide a place where Linux geeks can talk about interests and projects even if they might not be strictly Linux-related. We invite you to send proposals for #geeklife articles to ljeditor@linuxjournal.com.

For this first #geeklife article, I'm telling the story of a geeky, connected working road trip I just took in my RV, and within that context, I also review a particular piece of hardware I hoped would make the trip possible, the weBoost Drive 4G-X OTR. In the interest of full disclosure, Wilson Electronics provided me with this review unit, and I did not purchase it independently.

Working Remotely

My job is 100% remote. It took me many years of braving multi-hour California Bay Area commutes and turning down opportunities to find a job where I finally could work completely from home. Smart organizations are finally beginning to realize the many advantages to having a remote workforce, but I've found it works best if you have the right team, the right tools and the bulk of the workforce is remote. When everyone is distributed, everyone relies on the incredible modern collaboration tools currently available, and you have focus and incredible productivity when you need it while still being able to communicate with your peers.

My wife is a freelance writer and has worked from her home office long before I also worked from home. Once I also landed a job where I was completely remote, we posed the following question to ourselves: in theory, we could work from anywhere with a decent internet connection, but in practice, is that really something we could do? What would that kind of working trip look like?

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DIY RV Offsite Backup and Media Server

Kyle Rankin — Tue, 10 Jul 2018 11:45:00 +0000

by Kyle Rankin

What better way to add a geeky touch to #vanlife than with a Linux server in your RV?

One easily could make the strong argument that an RV is the ultimate DIY project playground. It combines all of the DIY projects you could perform on a vehicle with the DIY projects for a home. Add to that the fact that you may spend days living in a small house on wheels navigating highways, forests and deserts, and you have a whole other class of DIY projects to make the most of that smaller space. RVs also offer a whole suite of power options from 12V deep cycle batteries to 110V shore power to generators and alternators to solar power, so there's a whole class of electrical DIY projects related to making the most of your changing power options.

And if you're a geek, having an RV introduces a whole other level of DIY possibilities. First, there are all of the electronics projects to manage switching between power sources, tracking energy consumption and keeping those batteries charged. Then there's an entire category of projects related to internet access while away from home that involve everything from mobile WiFi hotspots to cellular-boosting networks to roving satellite internet (and if you're clever, a smart router that routes you to the best and cheapest available option). Finally, there are several project possibilities related to the computer systems in the RV, including local switches and routers, personal computers that turn the RV into a mobile office, and media centers so you can watch TV and movies from the road.

It just so happens that I recently got an RV—a 1996 Roadtrek 170 to be exact. Although this purchase has spawned a huge list of DIY projects, my very first Linux-based project focuses on the media center. At home, my media center is a Raspberry Pi running OSMC, and it works great for accessing my ripped DVDs and CDs from my NAS and playing them on my living-room TV. When I got the RV, I realized that one of the first things we'd want is a way to access all of that media from the road, even if we were in the middle of the woods.

In this article, I describe all the steps I took to build a media server just for the RV that maintains an up-to-date copy of my media and even syncs up automatically when it's parked in my driveway. It turns out that in the process of building a media server, I ended up with a pretty great off-site backup solution as well. Even if you don't own an RV, you could adapt these steps to add your own semi-offsite backup to your car.

Figure 1. Introducing "Van Winkle" (Photo Credit: Joy Rankin)

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Building a Voice-Controlled Front End to IoT Devices

Michael J. Hammel — Mon, 25 Jun 2018 13:44:37 +0000

by Michael J. Hammel

Apple, Google and Amazon are taking voice control to the next level. But can voice control be a DIY project? Turns out, it can. And, it isn't as hard as you might think.

Siri, Alexa and Google Home can all translate voice commands into basic activities, especially if those activities involve nothing more than sharing digital files like music and movies. Integration with home automation is also possible, though perhaps not as simply as users might desire—at least, not yet.

Still, the idea of converting voice commands into actions is intriguing to the maker world. The offerings from the big three seem like magic in a box, but we all know it's just software and hardware. No magic here. If that's the case, one might ask how anyone could build magic boxes?

It turns out that, using only one online API and a number of freely available libraries, the process is not as complex as it might seem. This article covers the Jarvis project, a Java application for capturing audio, translating to text, extracting and executing commands and vocally responding to the user. It also explores the programming issues related to integrating these components for programmed results. That means there is no machine learning or neural networks involved. The end goal is to have a selection of key words cause a specific method to be called to perform an action.

APIs and Messaging

Jarvis started life several years ago as an experiment to see if voice control was possible in a DIY project. The first step was to determine what open-source support already existed. A couple weeks of research uncovered a number of possible projects in a variety of languages. This research is documented in a text document included in the docs/notes.txt file in the source repository. The final choice of a programming language was based on the selection of both a speech-to-text API and a natural language processor library.

Since Jarvis was experimental (it has since graduated to a tool in the IronMan project), it started with a requirement that it be as easy as possible to get working. Audio acquisition in Java is very straightforward and a bit simpler to use than in C or other languages. More important, once audio is collected, an API for converting it to text would be needed. The easiest API found for this was Google's Cloud Speech REST API. Since both audio collection and REST interfaces are fairly easy to handle in Java, it seemed that would be the likely choice of programming language for the project.

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Piventory: LJ Tech Editor's Personal Stash of Raspberry Pis and Other Single-Board Computers

Kyle Rankin — Thu, 14 Jun 2018 12:00:00 +0000

by Kyle Rankin

It's like an extra-geeky episode of Cribs featuring single-board computers.

I'm a big fan of DIY projects and think that there is a lot of value in doing something yourself instead of relying on some third party. I mow my own lawn, change my own oil and do most of my own home repairs, and because of my background in system administration, you'll find all sorts of DIY servers at my house too. In the old days, geeks like me would have stacks of loud power-hungry desktop computers around and use them to learn about Linux and networking, but these days, VMs and cloud services have taken their place for most people. I still like running my own servers though, and thanks to the advent of these tiny, cheap computers like the Raspberry Pi series, I've been able to replace all of my home services with a lot of different small, cheap, low-power computers.

Occasionally, I'll hear people talk about how they have a Raspberry Pi or some other small computer lying around, but they haven't figured out quite what to do with it yet. And it always shocks me, because I have a house full of those small computers doing all sorts of things, so in this article, I describe my personal "Piventory"—an inventory of all of the little low-power computers that stay running around my house. So if you're struggling to figure out what to do with your own Raspberry Pi, maybe this article will give you some inspiration.

Primary NAS and Central Server

In "Papa's Got a Brand New NAS" I wrote about my search for a replacement for my rackmount server that acted as a Network-Attached Storage (NAS) for my house, along with a bunch of other services. Ultimately, I found that I could replace the whole thing with an ODroid XU4. Because of its octo-core ARM CPU, gigabit networking and high-speed USB3 port, I was able to move my hard drives over to a Mediasonic Probox USB3 disk array and set up a new low-power NAS that paid for itself in electricity costs.

In addition to a NAS, this server provides a number of backup services for my main server that sits in a data center. It acts as a backup mail server, authoritative DNS, and it also provides a VPN so I can connect to my home network from anywhere in the world—not bad for a little $75 ARM board.

Figure 1. Papa's New NAS

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Linux Gets Loud

Joshua Curry — Wed, 13 Jun 2018 13:08:08 +0000

by Joshua Curry

Exploring the current state of musical Linux with interviews of developers of popular packages.

Linux is ready for prime time when it comes to music production. New offerings from Linux audio developers are pushing creative and technical boundaries. And, with the maturity of the Linux desktop and growth of standards-based hardware setups, making music with Linux has never been easier.

Linux always has had a place for musicians looking for inexpensive rigs to record and create music, but historically, it's been a pain to maintain. Digging through arcane documentation and deciphering man pages is not something that interests many musicians.

Loading up Linux is not as intimidating as it once was, and a helpful community is going strong. Beyond tinkering types looking for cheap beats, users range in experience and skill. Linux is still the underdog when it comes to its reputation for thin creative applications though.

Recently, musically inclined Linux developers have turned out a variety of new and updated software packages for both production and creative uses. From full-fledged DAWs (Digital Audio Workstations), to robust soft-synths and versatile effects platforms, the OSS audio ecosystem is healthy.

A surge in technology-focused academic music programs has brought a fresh crop of software-savvy musicians into the fold. The modular synth movement also has nurtured an interest in how sound is made and encouraged curiosity about the technology behind it.

One of the biggest hurdles in the past was the lack of core drivers for the wide variety of outboard gear used by music producers. With USB 2.0 and improvements in ALSA and JACK, more hardware became available for use. Companies slowly have opened their systems to third-party developers, allowing more low-level drivers to be built.

Hardware

In terms of raw horsepower, the ubiquity of multicore processors and cheap RAM has enabled Linux to take advantage of powerful machines. Specifically, multithreaded software design available to developers in the Linux kernel offer audio packages that offload DSP and UI to various cores. Beyond OS multithreading, music software devs have taken advantage of this in a variety of ways.

A well known API called Jack Audio Connection Kit (JACK) handles multiple inter-application connections as well as audio hardware communication with a multithreaded approach, enabling low latency with both audio DSP and MIDI connections.

Ardour has leveraged multithreaded processing for some time. In early versions, it was used to distribute audio processing and the main interface and OS interaction to separate cores. Now it offers powerful parallel rendering on a multitude of tracks with complex effects.

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Linux Journal June Issue: Do-It-Yourself

Carlie Fairchild — Fri, 01 Jun 2018 03:36:34 +0000

by Carlie Fairchild

As tech editor Kyle Ranklin so aptly put it, June's Do-It-Yourself issue is "like an extra-geeky episode of Cribs featuring single-board computers".

In this issue:

Make Your Own RV Offsite Backup and Media Server
Create a Custom Minimal Linux Distribution from Source
Build a Voice-Controlled Front End for IoT Devices
Introducing PyInstaller
Shell Scripting a Password Generating Tool
OpenStreetMap Should Be a Priority to the Open Source Community
The Current State of Linux and Music
Open Hardware and IoT
A Programmer's Look at Jakarta EE
JaxoDraw for Physics
FOSS Project Spotlights: Codelobster and WallPaperDownloader

Subscribers, you can download your June issue now.

Not a subscriber? It’s not too late. Subscribe today and receive instant access to this and ALL back issues since 1994!

Want to buy a single issue? Buy the June magazine or other single back issues in the LJ store.

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