Software Hacks

958 Articles

The Orb Web Desktop

August 8, 2023 by 28 Comments

[Hugo Leisink] is a programmer who contributes to Open Source projects. In their spare time, they have been developing a web-browser-based operating system called Orb. It is available for the princely sum of zero cheeseburgers and doesn’t need a high-spec machine to run smoothly. The project is built using PHP and Javascript, which allows it to run efficiently on most desktop devices. There are a number of apps included, which are again written in a combination of PHP and js, together with a few written using webasm.

A few notable examples include a C64 emulator, minesweeper, and even a js port of Wolfenstein 3D so this isn’t just a toy, but actually useful. Ok, for real use cases, there are also the usual file browsers, and document readers as well as a writing application based on CKeditor. There is a kind of Windows 3.1 look and feel simplicity to the experience which is refreshing in the modern era of complex applications with their learning curves. Orb could be very useful in an educational setting, or just for jotting your own notes as you travel. Who knows, because the possibilities are endless if you’re willing to get your hands dirty with a bit of coding.

We’ve seen a few web desktops before, here’s a collection of them we saw last year. If you want to go in the other direction and turn a webpage into a desktop app, then look no further than Gluon.

Browser-Based Robot Dog Simulator In ~800 Lines Of Code

August 5, 2023 by 9 Comments

[Sergii] has been learning about robot simulation and wrote up a basic simulator for a robodog platform: the Unitree A1. It only took about 800 lines of code to do so, which probably makes it a good place to start if one is headed in a similar direction.

Right now, [Sergii]’s simulator is an interactive physics model than runs in the browser. Software-wise, once the model of the robot exists the Rapier JavaScript physics engine takes care of the physics simulation. The robot’s physical layout comes from the manufacturer’s repository, so it doesn’t need to be created from scratch.

To make the tool useful, the application has two models of the robot, side by side. The one on the left is the control model, and has interactive sliders for limb positions. All movements on the control model are transmitted to the model on the right, which is the simulation model, setting the pose. The simulation model is the one that actually models the physics and gravity of all the desired motions and positions. [Sergii]’s next step is to use the simulator to design and implement a simple walking gait controller, and we look forward to how that turns out.

If Unitree sounds familiar to you, it might be because we recently covered how an unofficial SDK was able to open up some otherwise-unavailable features on the robodogs, so check that out if you want to get a little more out of what you paid for.

Kalman Filters Without The Math

August 2, 2023 by 25 Comments

If you program using values that represent anything in the real world, you have probably at least heard of the Kalman filter. The filter allows you to take multiple value estimates and process them into a better estimate. For example, if you have a robot that has an idea of where it is via GPS, dead reckoning, and an optical system, Kalman filter can help you better estimate your true position even though all of those sources have some error or noise. As you might expect, a lot of math is involved, but [Pravesh] has an excellent intuitive treatment based around code that even has a collaborative Jupyter notebook for you to follow along.

We have always had an easier time following code than math, so we applaud these kinds of posts. Even if you want to dig into the math, having basic intuition about what the math means first makes it so much more approachable.

Continue reading “Kalman Filters Without The Math” →

Jenny’s Daily Drivers: FreeBSD 13.2

August 1, 2023 by 28 Comments

Last month I started a series in which I try out different operating systems with the aim of using them for my everyday work, and my pick was Slackware 15, the latest version of the first Linux distro I tried back in the mid 1990s. I’ll be back with more Linux-based operating systems in due course, but the whole point of this series is to roam as far and wide as possible and try every reasonable OS I can. Thus today I’m making the obvious first sideways step and trying a BSD-based operating system. These are uncharted waters for me and there was a substantial choice to be made as to which one, so after reading around the subject I settled on FreeBSD as it seemed the most accessible.

First, A Bit Of Context

A PC with the FreeBSD boot screen
Success! My first sight of a working FreeBSD installation.

Most readers will be aware that the BSD operating systems trace their heritage in a direct line back to the original AT&T UNIX, while GNU/Linux is a pretty good UNIX clone originating with Linus Torvalds in the early 1990s and Richard Stallman’s GNU project from the 1980s onwards. This means that for Linux users there’s a difference in language to get used to.

Where Linux is a kernel around which distributions are built with different implementations of the userland components, the various BSD operating systems are different operating systems in their own right. Thus we talk about for example Slackware and Debian as different Linux distributions, but by contrast NetBSD and FreeBSD are different operating systems even if they have a shared history. There are BSD distributions such as GhostBSD which use FreeBSD as its core, but it’s a far less common word in this context. So I snagged the FreeBSD 13.2 USB stick file from the torrent, and wrote it to a USB Flash drive. Out with the Hackaday test PC, and on with the show. Continue reading “Jenny’s Daily Drivers: FreeBSD 13.2” →

An Open-Source, Free Circuit Simulator

July 30, 2023 by 60 Comments

The original circuit simulation software, called the Simulation Program with Integrated Circuit Emphasis, or SPICE as it is more commonly known, was originally developed at the University of Califorina Berkeley in the 1970s with an open-source license. That’s the reason for the vast versions of SPICE available now decades after the original was released, not all of which are as open or free as we might like. Qucs is a GPL circuit simulator. And if you want the GUI option, you might want to try out QucsStudio, which uses Qucs under the hood, and is free to use, but binary-only.

(Editor’s note: the author was confused between the GPL open-source Qucs and the closed-source, binary-only QucsStudio. We’ve cleaned that up.)

QucsStudio supports a wide range of circuit components and models much in the same fashion as other more popular SPICE programs, including semiconductor devices, passive components, and digital logic gates. Qucs also utilizes SPICE-based simulation, which can model various types of circuit behavior, such as DC, AC, transient, and small-signal analysis.

Unfortunately there are only Windows versions available, and although some might have some success running it under WINE. There are plenty of other options for those of us running non-Windows operating systems though. Here’s a review of 30 of them.

Thanks to [Electroagenda] for the tip!

Where Old Files Go To Die

July 26, 2023 by 30 Comments

We all lead digital lives, and we work in and on files of one sort or another. And sometimes we get attached to them. That long manifesto you poured your heart into, but nonetheless probably shouldn’t see the light of day? Love letters from former flames? Your first favorite video game that you can’t play any more, but it just sits there eating up drive space?

These are the files that are important enough that they deserve better than just a drag-and-drop into the trashcan. They deserve to be buried with dignity, and that’s just what [Ulf Schleth]’s /death/null offers us – a digital graveyard where our files no longer exist as they were, but still are allowed to linger in memory.

This is an old project, but one that tickled our funny  and poignant bones in equal parts. The pun on /dev/null probably works just a little better if you read both filepaths with a German accent in your head, but the idea translates anyway.

To use it, you simply upload your file and it gets sent to the great trashcan in the sky, but along the way a 4 x 5 matrix of colored blocks is created that represents the file, and it is registered forever in the graveyard, where you can check up on it any time you like. Of course you can’t read it – only 20 RGB triples remain – but you have the digital “gravestone” as commemoration.

Even if you don’t have any loved ones in [Ulf]’s graveyard, you can walk by and see which files others have chosen to remember. Swing on by and pay your respects to notepad.exe.

Grab Your ‘Scope’s Screen From The Command Line

July 25, 2023 by 9 Comments

Many of us have oscilloscopes and other instruments with built-in digital interfaces, but how many of us use them? [Andrej Radović] has a Tektronix TDS2022 which can print its screen to any of its various interfaces, and he set about automating the process of acquisition with a Bash script.

The easiest interface to use was the trusty serial port — hardly the fastest but definitely the best supported. But how does one retrieve an image fired down a serial port? Most of the post is devoted to spotting file headers in a Bash script monitoring the serial port, and streaming the result to a local file. There’s a discussion of the various formats supported by the Tek, with an ancient PCX bitmap format being chosen over Postscript for speed. The result is a decent quality screen grab, making the ‘scope that little bit more useful and perhaps extending its life.

Perhaps your instrument isn’t a TEK, but the chances are you can still make it bend to your will from a PC. Try it, with the magic of VISA.