[David Lovett] aka Usagi Electric is taking a dive into yet another old computer design, this one from the early 1960s. He recently obtained eight mystery circuit boards on-loan for the purpose of reverse engineering them. It turns out these came from an old mainframe called the Bendix G-20, a successor to the 1965 G-15 vacuum tube model. The cards are:
Quad Inverting Amplifier
Most of these are pretty straightforward to figure out, but he ran into some troubles trying to understand the full adder board. The first issue is there is some uncertainty surrounding the logic level voltages. This system uses negative voltages, with -3.5 V representing a logic 1 … or is it a logic 0? And even taking into account this ambiguity, [David] is having a hard time deciphering how the adder works. It uses a bunch of diodes to implement a logic lookup table of an adder — except he is not able to make it match any known addition scheme. [David] has called out to the community for help on this one, and if you have any ideas how this adder works, visit his wiki linked above for more information and give him shout.
The AquaPing is a so-called “stand-off” sensor that is intended to detect leaks at a distance, even if they are inside a wall. No contact is needed with the plumbing itself. Instead, the device detects the broadband high-frequency noise created when water leaks from a pipe under pressure.
It’s a method that’s best suited to leaks from cracks or loose fittings. These generate a characteristic hiss that can be picked up with signal analysis even if the noise itself is obscured to human perception by other noises in the area. However, leaks like a hole in a gutter or a dripping rusted-out water tank are best found by other methods, as they don’t create this same signature noise.
The device will soon be launched on CrowdSupply as a purchasable product, however the project is fully open source for those eager to dive in themselves. We’ve featured some other really creative leak detectors before, too! Video after the break.
At Hackaday, we love those times when we get a chance to follow up on a project that we’ve already featured. Generally, it’s because the project has advanced in some significant way, which is always great to see. Sometimes, though, new details on the original project are available, and that’s where we find ourselves with [Scott Bez] and his haptic smart knob project.
Alert readers may recall [Scott]’s announcement of this project back in March. It made quite a splash, with favorable comments and a general “Why didn’t I think of that?” vibe. And with good reason; the build quality is excellent, and the idea is simple yet powerful. By attaching a knob to the shaft of a brushless DC motor and mounting a small circular LCD screen in the middle, [Scott] came up with an input device that could be reprogrammed on the fly. The BLDC can provide virtual detents at any interval while generating haptic feedback for button pushes, and the LCD screen can provide user feedback.
But how is such a thing built? That’s the subject of the current video, which has a ton of neat design details and build insights. The big challenge for [Scott] was supporting the LCD screen in the middle of the knob while still allowing the knob — and the motor — to rotate. Part of the solution was, sadly, a hollow-shaft motor that was out of stock soon after he released this project; hopefully a suitable replacement will be available soon. Another neat feature is the way [Scott] built tiny strain gauges into the PCB itself, which pick up the knob presses that act as an input button. We also found the way button press haptics are provided by a quick jerk of the motor shaft very clever.
This is one of those projects that seems like a solution waiting for a problem, and something that you’d build just for the coolness factor. Hats off to [Scott] for following up a sweet build with equally juicy details.
USB-C seeks to rule the roost when it comes to connectors, and even has Big Europe on its side. Apple hasn’t had to abandon Lightning just yet, but [Restore Technique] has put a USB-C port into an iPhone 13 to give us all an idea what it’s going to be like in the brave new future ahead of us.
The idea came about after disassembling the iPhone 13, and the project was locked in after seeing the first iPhone with a USB-C connector sell for $86,001 on eBay. The plan had to support fast charging, cable reversibility, and data transfer, without cutting out any functionality or compromising water resistance.
The concept is simple enough: take the C94 board from a Lightning to USB-C cable, and put it inside the phone along with a USB-C port. Of course, actually achieving that is the real challenge. Techniques from melting apart Lightning connectors to carefully peeling apart 0.5 mm pitch flex cables to fit 0.6 mm pitch pads.
It’s an impressive hack, and explained so well it’s actually tempting to try it at home for the sheer challenge of the thing. If you do pull off a similar hack yourself, drop us a line! Video after the break.
The desk of any self-respecting technology enthusiast in the 2020s is not complete without a special keyboard of some sort, be it a vintage IBM Model M, an esoteric layout or form factor, or just a standard keyboard made with clacky mechanical switches. But perhaps we’ve found the one esoteric keyboard to rule them all, in the form of [HIGEDARUMA]’s 8-bit keyboard. You can all go home now, the competition has been well and truly won by this input device with the simplest of premises; enter text by setting the ASCII value as binary on a row of toggle switches. No keyboard is more retro than the one you’d find on the earliest microcomputers!
Jokes aside, perhaps this keyboard may be just a little bit esoteric for many readers, but it’s nevertheless a well-executed project. Aside from the row of binary inputs there is a keypress button which sends whatever the value is to the computer, and a stock button that allows for multiple inputs to be stored and sent as one. If you pause for a moment and think how often you use Ctrl-C and Ctrl-V for example, this is an essential function. There’s more information on a Japanese website (Google Translate link), which reveals that under the hood it’s a Bluetooth device running on an ESP32.
We can imagine that with a bit of use it would be possible to memorize ASCII as binary pretty quickly, in fact we wouldn’t be at all surprised to find readers already possessing that skill. But somehow we can’t imagine it ever being a particularly fast text input device. Take a look for yourselves, it’s in the video below the break.
It’s fair to say that there’s really no phase of spaceflight that could be considered easy. But the case could be made that the most difficult part of a spacecraft’s journey is right at the very beginning, within the first few minutes of flight. At this point the vehicle’s booster rocket will be fighting with all its might against its own immense propellant-laden mass, a battle that it’s been engineered to win by the smallest of margins. Assuming the balance was struck properly and the vehicle makes its way off of the launch pad, it will still need to contend with the thick sea-level atmosphere as it accelerates, a building dynamic pressure that culminates with a point known as “Max q” — the moment where the air density imposes the maximum structural load on the rocket before quickly dropping off as the vehicle continues to ascend and the atmosphere thins.
While the vast majority of rocket launches have to contend with the realities of flying through the lower atmosphere, there are some exceptions. By launching a rocket from an aircraft, it can avoid having to power itself up from sea level. This allows the rocket to be smaller and lighter, as it doesn’t require as much propellant nor do its engines need to be as powerful.
The downside of this approach however is that even a relatively small rocket needs a very large aircraft to carry it. For example, Virgin Orbit’s LauncherOne rocket must be carried to launch altitude by a Boeing 747-400 airliner in order to place a 500 kg (1,100 lb) payload into orbit.
But what if there was another way? What if you could get all the benefits of starting your rocket from a higher altitude, without the cost and logistical issues involved in carrying it with a massive airplane? It might sound impossible, but the answer is actually quite simple…all you have to do it throw it hard enough.
Fresh from vacation, Editor-in-Chief Elliot Williams makes his triumphant return to the Hackaday Podcast! He’s joined this week by Managing Editor Tom Nardi, who’s just happy he didn’t have to do the whole thing by himself again. In this episode we’ll talk about tackling BGA components in your custom PCBs, a particularly well executed hack against Google’s Nest Hub, and why you probably don’t really want the world’s cheapest 3D printer. We’ll also take a look at an incredible project to turn the Nokia 1680 into a Linux-powered handheld computer, a first of its kind HDMI firewall, and a robot that’s pretty good at making tacos. Listeners who are into artificial intelligence will be in for quite a treat as well, as is anyone who dreams of elevating the lowly automotive alternator to a more prominent position in the hacker world.
By the way, it seems nobody has figured out the hidden message in last week’s podcast yet. What are you waiting for? One of you out there has to be bored enough to give it a shot.