This excellent content from the Hackaday writing crew highlights recurring topics and popular series like Linux-Fu, 3D-Printering, Hackaday Links, This Week in Security, Inputs of Interest, Profiles in Science, Retrotechtacular, Ask Hackaday, Teardowns, Reviews, and many more.
This week Jonathan and Dan chat with Frank Vasquez and Chris Simmonds about Embedded Linux, and the 4th edition of the Mastering Embedded Linux Programming book. How has this space changed in the last 20 years, and what’s the latest in Embedded Linux?
Continue reading “FLOSS Weekly Episode 846: Mastering Embedded Linux Programming”
Last time, I described how to write a simple Android app and get it talking to your code on Linux. So, of course, we need an example. Since I’ve been on something of a macropad kick lately, I decided to write a toolkit for building your own macropad using App Inventor and any sort of Linux tools you like.
I mentioned there is a server. I wrote some very basic code to exchange data with the Android device on the Linux side. The protocol is simple:
You can build the server so that it can execute arbitrary commands. Since some people will doubtlessly be upset about that, the server can also have a restrictive set of numbered commands. You can also allow those commands to take arguments or disallow them, but you have to rebuild the server with your options set.
There is a handshake at the start of communications where Android sends “>.” and the server responds “<.” to allow synchronization and any resetting to occur. Sending “>#x” runs a numbered command (where x is an integer) which could have arguments like “>#20~/todo.txt” for example, or, with no arguments, “>#20” if you just want to run the command.
If the server allows it, you can also just send an entire command line using “>>” as in: “>>vi ~/todo.txt” to start a vi session.
[Rex Malik] didn’t need an alarm clock. That’s because he had one of two “home computer terminals” next to his bed and, as you can see in the video below, it made quite a racket. The terminal looks like an ASR33 with some modifications. In 1967, it was quite a novelty and, of course, it didn’t have any real processing power. It connected to an “invisible brain” ten miles away.
What do you do with a computer in 1967? Well, it looks like you could trade stocks. It also apparently managed his shopping list and calendar. His young son also learned some letters and numbers. We’d love to hear from the young [Mr. Malik] today to find out what kind of computer he’s using now.
Continue reading “Retrotechtacular: The Noisy Home Computer From 1967”
There’s a saying in mine country, the kind that sometimes shows up on bumper stickers: “If it can’t be grown, it has to be mined.” Before mining can ever start, though, there has to be ore in the ground. In the last edition of this series, we learned what counts as ore (anything that can be economically mined) and talked about the ways magma can form ore bodies. The so-called magmatic processes are responsible for only a minority of the mines working today. Much more important, from an economic point of view, are the so-called “hydrothermal” processes.
When you hear the word “hydrothermal” you probably think of hot water; in the context of geology, that might conjure images of Yellowstone and regions like it : Old Faithful geysers and steaming hot springs. Those hot springs might have a role to play in certain processes, but most of the time when a geologist talks about a “hydrothermal fluid” it’s a lot hotter than that.
Is there a point on the phase diagram that we stop calling it water? We’re edging into supercritical fluid territory, here. The fluids in question can be hundreds of degrees centigrade, and can carry things like silica (SiO2) and a metal more famous for not dissolving: gold. Perhaps that’s why we prefer to talk about a “fluid” instead of “water”. It certainly would not behave like water on surface; on the surface it would be superheated steam. Pressure is a wonderful thing.
Let’s return to where we left off last time, into a magma chamber deep underground. Magma isn’t just molten rock– it also contains small amounts of dissolved gasses, like CO2 and H2O. If magma cools quickly, the water gets trapped inside the matrix of the new rock, or even inside the crystal structure of certain minerals. If it cools slowly, however? You can get a hydrothermal fluid within the magma chamber.
Continue reading “Ore Formation Processes, Part Two: Hydrothermal Boogaloo”
Two weeks ago, it was holographic cops. This week, it’s humanoid robot doctors. Or is it? We’re pretty sure it’s not, as MediBot, supposedly a $10,000 medical robot from Tesla, appears to be completely made up. Aside from the one story we came across, we can’t find any other references to it, which we think would make quite a splash in the media if it were legit. The article also has a notable lack of links and no quotes at all, even the kind that reporters obviously pull from press releases to make it seem like they actually interviewed someone.
Aside from a few stand-out programs — looking at you, Star Trek — by the late 1960s, TV had already become the “vast wasteland” predicted almost a decade earlier by Newton Minnow. But for the technically inclined, the period offered no end of engaging content in the form of wall-to-wall coverage of anything and everything to do with the run-up to the Apollo moon landings. It was the best thing on TV, and even the endless press conferences beat watching a rerun of Gilligan’s Island.
At the time, most of the attention landed on the manned missions, with the photogenic and courageous astronauts of the Mercury, Gemini, and Apollo programs very much in the limelight. But for our money, it was the unmanned missions where the real heroics were on display, starring the less-photogenic but arguably vastly more important engineers and scientists who made it all possible. It probably didn’t do much for the general public, but it sure inspired a generation of future scientists and engineers.
With that in mind, we were pleased to see this Surveyor 1 documentary from Retro Space HD pop up in our feed the other day. It appears to be a compilation of news coverage and documentaries about the mission, which took place in the summer of 1966 and became the first lunar lander to set down softly on the Moon’s surface. The rationale of the mission boiled down to one simple fact: we had no idea what the properties of the lunar surface were. The Surveyor program was designed to take the lay of the land, and Surveyor 1 in particular was tasked with exploring the mechanical properties of the lunar regolith, primarily to make sure that the Apollo astronauts wouldn’t be swallowed whole when they eventually made the trip President Kennedy had mandated back in 1961.
The video below really captures the spirit of these early missions, a time when there were far more unknowns than knowns, and disaster always seemed to be right around the corner. Even the launch system for Surveyor, the Atlas-Centaur booster, was a wild card, having only recently emerged from an accelerated testing program that was rife with spectacular failures. The other thing the film captures well is the spacecraft’s nail-biting descent and landing, attended not only by the short-sleeved and skinny-tied engineers but by a large number of obvious civilians, including a few lucky children. They were all there to witness history and see the first grainy but glorious pictures from the Moon, captured by a craft that seemed to have only just barely gotten there in one piece.
The film is loaded with vintage tech gems, of course, along with classic examples of the animations used at the time to illustrate the abstract concepts of spaceflight to the general public. These sequences really bring back the excitement of the time, at least for those of us whose imaginations were captured by the space program and the deeds of these nervous men and women.
NASA wants to return to the moon. They also want you to help. Turns out making a good landing on the moon is harder than you might think.
Continue reading “Retrotechtacular: Exploring The Moon On Surveyor 1“
Thunderstorms were raging across southern Germany as Elliot Williams was joined by Jenny List for this week’s podcast. The deluge outside didn’t stop the hacks coming though, and we’ve got a healthy smorgasbord for you to snack from. There’s the cutest ever data cassette recorder taking a tiny Olympus dictation machine and re-engineering it with a beautiful case for the Commodore 64, a vastly overcomplex machine for perfectly cracking an egg, the best lightning talk timer Hackaday has ever seen, and a demoscene challenge that eschews a CPU. Then in Quick Hacks we’ve got a QWERTY slider phone, and a self-rowing canoe that comes straight out of Disney’s The Sorcerer’s Apprentice sequence.
For a long time we’ve had a Field guide series covering tech in infrastructure and other public plain sight, and this week’s one dealt with pivot irrigation. A new subject for Jenny who grew up on a farm in a wet country. Then both editors are for once in agreement, over using self-tapping screws to assemble 3D-printed structures. Sit back and enjoy the show!
Want to listen offline? Grab yourself an MP3 hot off the press.
