If you’ve been on the RTL-SDR forums lately you may have seen that a lot of work has been going into the DragonOS software. This is a software-defined radio group that has seen a lot of effort put into a purpose-built Debian-based Linux distribution that can do a lot of SDR out of the box. The latest and most exciting project coming from them involves a method for using the software to receive and demodulate analog video.
[Aaron]’s video (linked below) demonstrates using a particular piece of software called SigDigger to analyze an incoming analog video stream from a drone using a HackRF. (Of course any incoming analog signal could be used, it doesn’t need to be a drone.) The software shows the various active frequency ranges, allows a user to narrow in on one and then start demodulating it. While it has to be dialed in just right to get anything that doesn’t look like snow, [Aaron] is able to get recognizable results in just a few minutes.
Getting something like this to work completely in software is an impressive feat, especially considering that all of the software used here is free. Granted, this wouldn’t be as easy for a digital signal like most TV stations broadcast, but there’s still a lot of fun to be had. In case you missed the release of DragonOS, we covered it a few weeks ago and it’s only gotten better since then, with this project just as one example.
Continue reading “Receive Analog Video Radio Signals From Scratch”
In the classic gaming world, even before the NES arrived on the scene, there was no name more ubiquitous than Atari. Their famous 2600 console sold almost as many units as the Nintendo 64, but was released nearly 20 years prior. In many ways, despite making mistakes that led to the video game crash of the early 80s, Atari was the first to make a path in the video game industry. If you want to explore what the era of 8-bit computing was like in the Atari age, a new resource is compiling all kinds of Atari-based projects.
This site has everything, from assembling Atari 8-bit computers based on the 6502 chip, to programming them in BASIC and assembly, to running official and homebrew games on the hardware itself. This was put together by [Jason H. Moore] who grew up around Atari systems and later, their home computers. He even puts his biomedical experience to use here by designing a game for the 2600 called Gene Medic which can be found at the site as well.
If you grew up in the 70s and 80s and are looking for a bit of Atari nostalgia this site is the place to go. It’s even worth a visit from younger folks as well since the 8-bit world is a lot easier to get immersed in and learn the fundamentals of computer science. Of course, if you want to take it the other direction, it’s possible to modify the old Atari to add a few modern conveniences.
Photo via Evan-Amos
Not only do console gamers complain about the use of a mouse, but PC users themselves often don’t have kind words to say even about some of the higher-end options. Granted, their gripes aren’t about game experience or balance, they’re usually about comfort, features, or longevity of the mice themselves. So far we haven’t seen many people try to solve these problems, but [benw] recently stepped on the scene with a modular mouse that can fit virtually any need.
Called the RX-Modulus, this mouse has been designed from the ground up to be completely open source from hardware to software. Most of the components can be 3D printed to suit an individual’s particular grip style by making adjustments. The electronics can be custom fitted as well. Users can swap out mouse buttons and wheels in any number of positions, and replace them when they wear out. To that end, one of the goals of this project is also to avoid any planned obsolescence that typically goes along with any current consumer-level product.
While [benw] currently only has a few prototypes under his belt, he’s far enough along with the project that he’s willing to show it off to the community. His hopes are that there are others that see a need for this type of mouse and can contribute to the final design. After all, there are all kinds of other custom mice out there that would have been much easier builds with [benw]’s designs at hand.
Raspberry Pi clusters are a common enough project, but a lot of the builds we see focus on the hardware side of the cluster. Once it’s up and running, though, what comes next? Raspberry Pis aren’t very powerful devices, but they can still be a great project for learning how to interact with a cluster of computers or for experimental test setups. In this project from [Dino], four Pis are networked together and then loaded with a basic set of software for cluster computing.
The first thing to set up, after the hardware and OS, is the network configuration. Each Pi needs a static IP in order to communicate properly. In this case, [Dino] makes extensive use of SSH. From there, he gets to work installing Prometheus and Grafana to use as monitoring software which can track system resources and operating temperature. After that, the final step is to install Ansible which is monitoring software specifically meant for clusters, which allows all of the computers to be administered more as a unit than as four separate devices.
This was only part 1 of [Dino]’s dive into cluster computing, and we hope there’s more to come. There’s a lot to do with a computer cluster, and once you learn the ropes with a Raspberry Pi setup like this it will be a lot easier to move on to a more powerful (and expensive) setup that can power through some serious work.
Just a few decades ago, getting into hobby radio meant lots of specialty hardware, and making changes to your setup to work on various frequencies wasn’t particularly easy. Since software-defined radio (SDR) came onto the scene in an accessible way for most of us, this barrier to entry was reduced significantly and made the process of getting on the air a lot easier. It goes without saying that it does require some software, but [Aaron]’s latest project makes even getting that software extremely simple.
What he has done is created a custom Linux distribution based on Debian, called DragonOS, with the entire suite of SDR programs needed to get up and running. Out of the box, it supports RTL-SDR, HackRF and LimeSDR packages and even includes other fun tools you’ll need like Kismet. There are several video demonstrations of his distribution, including using RTL-SDR for ADS-B reception, and also shows off several custom implementations of the OS in various scenarios on his YouTube channel. The video linked below also shows how to set up the distribution in a virtual machine, so you can run this even if you don’t have a computer to dedicate to SDR.
Getting into SDR has never been easier, and the odds of having something floating around in the junk drawer that you can use to get started are pretty high. The process is exceptionally streamlined with [Aaron]’s software suite. If you’re a little short on hardware, though, there’s no better place to get started than with the classic TV-tuner-to-SDR hack from a few years back.
Continue reading “Software-Defined Radio Made Easy”
In the days of carburetors and leaf spring suspensions, odometer fraud was pretty simple to do just by disconnecting the cable or even winding the odometer backwards. With the OBD standard and the prevalence of electronics in cars, promises were made by marketing teams that this risk had all but been eliminated. In reality, however, the manipulation of CAN bus makes odometer fraud just as easy, and [Andras] is here to show us exactly how easy with a teardown of a few cheap CAN bus adapters.
We featured another project that was a hardware teardown of one of these devices, but [Andras] takes this a step further by probing into the code running on the microcontroller. One would imagine that basic measures would have been taken by the attackers to obscure code or at least disable debugging modes, but on this one no such effort was made. [Andras] was able to dump the firmware from both of his test devices and start analyzing them.
Analyzing the codes showed identical firmware running on both devices, which made his job half as hard. It looked like the code was executing a type of man-in-the-middle attack on the CAN bus which allowed it to insert the bogus mileage reading. There’s a lot of interesting information in [Andras]’s writeup though, so if you’re interested in CAN bus or attacks like this, it’s definitely worth a read.
For however many Linux distributions there are to choose from, there are perhaps even more window managers that can be paired with them, and some have dramatically different features than the X window systems that most of us are familiar with. There’s a rabbit hole to fall down, as with most Linux-related topics, but while this tiling window manager from [caoluin], called sara, adds to the cacophony, it’s also representative of any pet project that lets us take a deep dive into something personally interesting.
What started as a desire to revive an abandoned window manager called catwm eventually evolved into a fork of sorts of another popular window manager called dwm. dwm is used as a basis or as building blocks for many other window managers, and while [caoluin] was writing sara he found that many of the solutions he found converged on the same things that dwm had already implemented. In a way, it’s reassuring if your solutions are similar to tried-and-true methods already in use. For other things he found interesting solutions, and other features that dwm has he found to be unnecessary and removed them.
Does the world need another window manager? Probably not. But we can all appreciate building something from scratch, just to see how it really works under the hood. As far as that goes, we’d consider sara a success for [caoluin], and if you’re really interested in window managers then you can take a look at his Github page or one of the more esoteric window managers we’ve seen.