After being licensed as a ham radio operator since the early 2000s, you tend to start thinking about combining your love for the radio with other talents. In a 20-minute talk at Hackaday Supercon 2022, [Mooneer Salem] tells the story of one such passion project that combined software and radio to miniaturize a digital ham radio modulator.
[Mooneer] works as a software developer and contributes to a project called FreeDV (free digital voice), a digital voice mode for HF radio. FreeDV first compresses the digital audio stream, then converts it into a modulation scheme sent out over a radio. The appeal is that this can be understandable down to very low signal-to-noise ratios and includes metadata and all the other niceties that digital signals bring.
Traditionally, this has required a computer to compress the audio and modulate the signal in addition to two sound cards. One card processes the audio in and out of your headset, and another for the audio coming in and out of the radio. [David Rowe] and [Rick Barnich] developed the SM1000, a portable FreeDV adapter based around the STM32F4 microcontroller. However, flash space was running low, and the cost was more than they wanted. Continue reading “Supercon 2022: Mooneer Salem Goes Ham With An ESP32”→
The topic of energy has been top-of-mind for us since the first of our ancestors came down out of the trees looking for something to eat that wouldn’t eat them. But in a world where the neverending struggle for energy has been abstracted away to the flick of a finger on a light switch or thermostat, thanks to geopolitical forces many of us are now facing the wrath of winter with a completely different outlook on what it takes to stay warm.
The problem isn’t necessarily that we don’t have enough energy, it’s more that what we have is neither evenly distributed nor easily obtained. Moving energy from where it’s produced to where it’s needed is rarely a simple matter, and often poses significant and interesting engineering challenges. This is especially true for sources of energy that don’t pack a lot of punch into a small space, like natural gas. Getting it across a continent is challenging enough; getting it across an ocean is another thing altogether, and that’s where liquefied natural gas, or LNG, comes into the picture.
Turn the clock back a couple of decades, and the only time the average person would have given much thought to batteries was when the power would go out, and they suddenly needed to juice up their flashlight or portable radio. But today, high-capacity batteries have become part and parcel to our increasingly digital lifestyle. In fact, there’s an excellent chance the device your reading this on is currently running on battery power, or at least, is capable of it.
So let’s get to know batteries better. What’s the chemical process that allows them to work? For that matter, what even is a battery in the first place?
It’s these questions, and more, that made up this week’s Battery Engineering Hack Chat with Dave Sopchak. Our last Hack Chat of 2022 ended up being one of the longest in recent memory, with the conversation starting over an hour before the scheduled kickoff and running another half hour beyond when emcee Dan Maloney officially made his closing remarks. Not bad for a topic that so often gets taken for granted.
Hackaday has been around long enough to see incredible changes in what’s possible at the hobbyist level. The tools, techniques, and materials available today border on science-fiction compared to what the average individual had access to even just a decade ago. On a day to day basis, that’s manifested itself as increasingly elaborate electronic projects that in many cases bear little resemblance to the cobbled together gadgets which graced these pages in the early 2000s.
Kip Daugirdas
But these gains aren’t limited to our normal niche — hobbyists of all walks have been pushing their respective envelopes. Take for example the successful launch of MESOS, a homebuilt reusable multi-stage rocket, to the very edge of the Kármán line. It was designed and built by amateur rocket enthusiast Kip Daugirdas over the course of several years, and if all goes to plan, will take flight once again this summer with improved hardware that just might help it cross the internationally recognized 100 kilometer boundary that marks the edge of space.
We were fortunate enough to have Kip stop by the Hack Chat this week to talk all things rocketry, and the result was a predictably lively conversation. Many in our community have a fascination with spaceflight, and even though MESOS might not technically have made it that far yet (there’s some debate depending on who’s definition you want to use), it’s certainly close enough to get our imaginations running wild.
Humanity thus far has supplied most of its electricity needs by burning stuff, mostly very old stuff that burns great but is hard to replace. That stuff is getting increasingly expensive, and the pollution is a bother too, so renewable sources of energy are becoming more popular.
In the electronics world, even for the hobbyists, things have only gotten smaller over the years. We went from through-hole components to surface mount, and now we’re at the point where the experienced DIYers are coming around to the idea of using ball grid array (BGA) components in their designs. We’d wonder what things are going to look like in another couple decades, but frankly, it gives us the heebie-jeebies.
So while we’re pretty well versed these days in the hows and whys of tiny things, we see comparatively little large-scale engineering projects. Which is why we were excited to have Andy Oliver stop by this week for the Heavy Engineering Hack Chat. His day job sees him designing and inspecting the control systems for movable bridges — or what many would colloquially refer to as drawbridges.
Now you might think there’s not a lot of demand for this particular skill set, but we’re willing to bet there’s a lot more of these bridges out there than you realized. Andy kicked things off with the revelation that just between the states of Florida and Louisiana, there are about 200 movable bridges of various sizes. On a larger scale, he points out that BridgeHunter.com lists an incredible 3,166 movable bridges in their database, though admittedly many of those are historical and no longer standing. (There really is a site for everything!)
Andy Oliver
There’s also a huge incentive to keep the existing bridges functioning for as long as possible — building a new one these days could cost hundreds of millions of dollars. Instead, repairs and upgrades are the name of the game. Andy says that if it’s properly maintained, you should get about a century out of a good bridge.
It will probably come as little surprise to find that keeping things as simple as possible is key to making sure a movable bridge can withstand the test of time. While we might imagine that all sorts of high-tech automation systems are at work, and they probably would be if any of us were in charge, Andy says that most of the time it’s old school relay logic.
Even controlling the speed of motors is often down to using beefy relays to switch some additional resistance into the circuit. But when reliability and ease of repair are top priorities, who’s to argue against a classic? Andy recalled a time when a government client made it clear that the only tool you should need to maintain a particular bridge’s control system was a hammer.
Of course, when moving around a million pounds of steel, there’s more than just electrical considerations at play. You’ve also got to take into account things like wind forces on the bridge, specifically that your gears and motors can handle the extra load without tearing themselves apart. The bridge also needs an emergency stop system that can arrest movement at a moment’s notice, but not damage anything in the process.
A lot of fascinating details about these motorized behemoths were covered in the Chat, so we’d invite anyone who’s ever watched a bridge slowly reconfigure itself to peruse through the full transcript. Special thanks to Andy Oliver for stopping by and sharing some of the details about his unique career with the community, and remember that if you’ve got your own engineering stories to tell, we’d love to hear them.
The Hack Chat is a weekly online chat session hosted by leading experts from all corners of the hardware hacking universe. It’s a great way for hackers connect in a fun and informal way, but if you can’t make it live, these overview posts as well as the transcripts posted to Hackaday.io make sure you don’t miss out.
Since their relatively recent appearance on the commercial scene, rare-earth magnets have made quite a splash in the public imagination. The amount of magnetic energy packed into these tiny, shiny objects has led to technological leaps that weren’t possible before they came along, like the vibration motors in cell phones, or the tiny speakers in earbuds and hearing aids. And that’s not to mention the motors in electric vehicles and the generators in wind turbines, along with countless medical, military, and scientific uses.
These advances come at a cost, though, as the rare earth elements needed to make them are getting harder to come by. It’s not that rare earth elements like neodymium are all that rare geologically; rather, deposits are unevenly distributed, making it easy for the metals to become pawns in a neverending geopolitical chess game. What’s more, extracting them from their ores is a tricky business in an era of increased sensitivity to environmental considerations.
Luckily, there’s more than one way to make a magnet, and it may soon be possible to build permanent magnets as strong as neodymium magnets, but without any rare earth metals. In fact, the only thing needed to make them is iron and nitrogen, plus an understanding of crystal structure and some engineering ingenuity.
