The Wow! Signal And The Search For Extraterrestrial Intelligence

November 25, 2020 by 54 Comments

On a balmy August evening in 1977, an enormous radio telescope in a field in the middle of Ohio sat silently listening to the radio universe. Shortly after 10:00 PM, the Earth’s rotation slewed the telescope through a powerful radio signal whose passage was noted only by the slight change in tone in the song sung every twelve seconds by the line printer recording that evening’s data.

When the data was analyzed later, an astronomer’s marginal exclamation of the extraordinarily powerful but vanishingly brief blip would give the signal its forever name: the Wow! Signal. How we came to hear this signal, what it could possibly mean, and where it might have come from are all interesting details of an event that left a mystery in its wake, one that citizen scientists are now looking into with a fresh perspective. If it was sent from a region of space with habitable planets, it’s at least worth a listen.

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A Rocket Powered Ejection Seat For Model Aircraft

November 21, 2020 by 4 Comments

As radio control planes don’t typically have human pilots onboard, the idea of installing an ejection seat in one is somewhat frivolous. But that doesn’t mean it wouldn’t be a lot of fun, and [James Whomsley] has set his mind to achieving the task.

The build process is an iterative one, with [James] solving problems step-by-step and testing along the way. The first task was to successfully launch a small action figure and his flight seat vertically in a controlled fashion. After a few attempts, a combination of rocket motors and guide rails were settled upon that could achieve the goal. Next up, a drogue parachute system was designed and tested to stabilize the seat at the height of its trajectory. Further work to come involves handling seat separation and getting the action figure safely back to the ground.

While action figures aren’t alive and the ejection seat serves no real emergency purpose, we can imagine it would be a hit at the local flying field – assuming the parachutes don’t get tangled in someone else’s model. For those interested in the real technology, our own [Dan Maloney] did a great piece on the topic. Video after the break.

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Under The Sea GPS Uses Sound

November 8, 2020 by 18 Comments

If you’ve ever tried to use GPS indoors, you know that the signals aren’t easy to acquire in any sort of structure. Now imagine trying to get a satellite fix underwater. Researchers at MIT have a new technique, underwater backscatter localization or UBL, that promises to provide a low-power localization system tailored for the subsea environment.

Like other existing solutions, UBL uses sound waves, but it avoids some of the common problems with using sonic beacons in that environment. A typical system has a fixed beacon constrained by the availability of power or battery-operated beacons that require replacement or recharging. Since the beacon acts as a transponder — it receives a signal and then replies — it requires either constant power or time to wake up from the external stimulus and that time typically varies with the environment. That variable startup time interferes with computing the round-trip time of the signal, which is crucial for estimating position.

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Linux Fu: Global Search And Replace With Ripgrep

October 14, 2020 by 9 Comments

If you are even a casual Linux user, you probably know how to use grep. Even if you aren’t a regular expression guru, it is easy to use grep to search for lines in a file that match anything from simple strings to complex patterns. Of course, grep is fine for looking, but what if you want to find things and change them. Maybe you want to change each instance of “HackADay” to “Hackaday,” for example. You might use sed, but it is somewhat hard to use. You could use awk, but as a general-purpose language, it seems a bit of overkill for such a simple and common task. That’s the idea behind ripgrep which actually has the command name rg. Using rg, you can do things that grep can do using more modern regular expressions and also do replacements.

A Note on Installing Ripgrep

Your best bet is to get ripgrep from your repositories. When I tried running KDE Neon, it helpfully told me that I could install a version using apt or take a Snap version that was newer. I usually hate installing a snap, but I did anyway. It informed me that I had to add –classic to the install line because ripgrep could affect files outside the Snap sandbox. Since the whole purpose of the program is to change files, I didn’t think that was too surprising, so I did the install.

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Improved Part Searches For JLCPCB Parts

October 11, 2020 by 29 Comments

Finding the JLCPCB component parts library frustrating to navigate, [Jan Mrázek] took matters into his own hands and made an open-source parametric search utility. We’ve all probably wasted time before trying to track down a particular flavor of a part, and this tool promises to make the process easier.  It downloads data from the JLCPCB parts site upon initialization and presents the user with typical selection filters for categories and parameter values. You can install it yourself on GitHub Pages, or [Jan] provides a link to his site.

For the curious, the details of how to pull parts information from the JLBPCB site can be found in the project’s source code.  We like it when a distributor provides this level of access to their part details and parameters, allowing others to sort and filter the parts in ways not originally envisioned by the site design team.  We think this is a win-win situation — distributors can’t sell parts that designers can’t find.

If [Jan]’s name sounds familiar, it should be.  We have written about several of his projects before, two of them are also PCB designer tools ( KiCad Board Renderings and KiCad Panelization ).

This Week In Security: Code Scanning, Information Gathering, And Seams In The Cloud

October 9, 2020 by 6 Comments

GitHub has enabled free code analysis on public repositories. This is the fruit of the purchase of Semmle, almost exactly one year ago. Anyone with write permissions to a repository can go into the settings, and enable scanning. Beyond the obvious use case of finding vulnerabilities, an exciting option is to automatically analyse pull requests and flag potential security problems automatically. I definitely look forward to seeing this tool in action.

The Code Scanning option is under the Security tab, and the process to enable it only takes a few seconds. I flipped the switch on one of my repos, and it found a handful of issues that are worth looking in to. An important note, anyone can run the tool on a forked repo and see the results. If CodeQL finds an issue, it’s essentially publicly available for anyone who cares to look for it.

Simpler Code Scanning

On the extreme other hand, [Will Butler] wrote a guide to searching for exploits using grep. A simple example, if raw shows up in code, it often signals an unsafe operation. The terms fixme or todo, often in comments, can signal a known security problem that has yet to be fixed. Another example is unsafe, which is an actual keyword in some languages, like Rust. If a Rust project is going to have vulnerabilities, they will likely be in an unsafe block. There are some other language-dependent pointers, and other good tips, so check it out.

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Aruna: An Open Source ROV For Affordable Research

October 7, 2020 by 19 Comments

Underwater exploration and research can be exceedingly dangerous, which is why remotely operated vehicles (ROVs) are so commonly used. Operators can remotely command these small submersibles to capture images or collect samples at depths which would otherwise be unreachable. Unfortunately, such technology comes at a considerable price.

Believing that the high cost of commercial ROVs is a hindrance to aquatic conservation efforts, [Noeël Moeskops] has been developing an open source modular ROV he calls Aruna. Constructed largely from off-the-shelf components and 3D-printed parts, the Aruna promises to be far more affordable than anything currently on the market. Hopefully cheap enough to allow local governments and even citizens to conduct their own underwater research and observations.

More than just the ROV itself, Aruna represents an entire system for developing modular underwater vehicles. Whether you decide to build the boilerplate ROV documented and tested by [Noeël], or implement individual components into your own design, the project is a valuable source of hardware and software information for anyone interested in DIY underwater robotics.

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