The Case Of The Mysterious Driveline Noise

July 14, 2021 by Lewin Day 31 Comments

Spend enough time on the automotive classifieds and you’ll end up finding a deal that’s too good to pass up. The latest of these in one’s own case was a Mercedes-Benz sedan, just past its twentieth birthday and in surprisingly tidy condition. At less than $3,000, the 1998 E240 was too good to pass up and simply had to be seen.

The car in question. Clean bodywork is too tempting to resist, even if there are mechanical issues.

The car was clean, too clean for asking price. Of course, a test drive revealed the car had one major flaw – an annoying hum from the drivetrain that seemed to vary with speed. Overall though, mechanical problems are often cheaper and easier to fix than bodywork, so a gamble was taken on the German sedan. The first order of business was to diagnose and rectify the issue.

Characterise, Research, Investigate

The first step to hunting down any noise is to characterise it as much as possible. In this case, the noise was most noticeable when the car was traveling at speeds from 40 km/h – 60 km/h, present as a vibrational humming noise. The location of the noise source was unclear. Importantly, the noise varied with the speed of the car, raising in pitch at higher speeds and dropping as speeds decreased. Engine speed had no effect on noise whatsoever, and the noise was present regardless of gear selected in the transmission, including neutral. Continue reading “The Case Of The Mysterious Driveline Noise” →

Retrotechtacular: The Secret Life Of The Electric Light

July 13, 2021 by Dan Maloney 22 Comments

Normally, when we pick out something to carry the “Retrotechtacular” banner, it’s a film from the good old days when technology was young and fresh, and filmmakers were paid by one corporate giant or another to produce a film extolling the benefits of their products or services, often with a not-so-subtle “celebrate the march of progress” undertone.

So when we spied this remastered version of The Secret Life of the Electric Light, an episode from [Tim Hunkin]’s fabulous educational The Secret Life of Machines TV series, we didn’t really think it would be good Retrotechtacular fodder. But just watching a few minutes reminded us of why the series was must-see TV back in the 1990s (when it first aired widely here in the States), especially for the budding geek. When viewed with eyes more used to CGI animations and high production values, what [Tim] and his collaborator, the late [Rex Garrod], accomplished with each of these programs is truly astounding. Almost every bit of the material, as well as the delivery, has an off-the-cuff quality to it that belies what must have taken an enormous amount of planning and organization to pull off. [Tim] and [Rex] obviously went to a lot of trouble to make it look like they didn’t go to a lot of trouble, and the result is films that home in on the essentials of technology in a way few programs have ever managed, and none since. And the set-piece at the end of each episode — often meeting its pyrotechnic destruction — always were real crowd-pleasers. They still are.

We have to say the remastered versions of The Secret Life episodes, all of which appear to be posted at [Tim]’s YouTube channel, look just great, and the retrospectives at the end of each episode where he talks about the travails of production are priceless. Also posted are his more recent The Secret Life of Components, which is a treasure trove of practical tips for makers and backyard engineers that’s well worth watching too.

Continue reading “Retrotechtacular: The Secret Life Of The Electric Light” →

Virginia Apgar May Have Saved Your Life

July 13, 2021 by Kristina Panos 28 Comments

Between the 1930s and the 1950s, something sort of strange happened in the United States. The infant mortality rate went into decline, but the number of babies that died within 24 hours of birth didn’t budge at all. It sounds terrible, but back then, many babies who weren’t breathing well or showed other signs of a failure to thrive were usually left to die and recorded as stillborn.

As an obstetrical anesthesiologist, physician, and medical researcher, Virginia Apgar was in a great position to observe fresh newborns and study the care given to them by doctors. She is best known for inventing the Apgar Score, which is is used to quickly rate the viability of newborn babies outside the uterus. Using the Apgar Score, a newborn is evaluated based on heart rate, reflex irritability, muscle tone, respiratory effort, and skin color and given a score between zero and two for each category. Depending on the score, the baby would be rated every five minutes to assess improvement. Virginia’s method is still used today, and has saved many babies from being declared stillborn.

Virginia wanted to be a doctor from a young age, specifically a surgeon. Despite having graduated fourth in her class from Columbia University College of Physicians and Surgeons, Virginia was discouraged from becoming a surgeon by a chairman of surgery and encouraged to go to school a little bit longer and study anesthesiology instead. As unfortunate as that may be, she probably would have never have created the Apgar Score with a surgeon’s schedule. Continue reading “Virginia Apgar May Have Saved Your Life” →

Teardown: VTech Smart Start

July 12, 2021 by Tom Nardi 12 Comments

Regular readers may be aware that I have a certain affinity for vintage VTech educational toys, especially ones that attempted to visually or even functionally tie in with contemporary computer design. In the late 1980s, when it became obvious the personal computer was here to stay, these devices were seen as an affordable way to give kids and even young teens hands-on time with something that at least somewhat resembled the far more expensive machines their parents were using.

A perfect example is the PreComputer 1000, released in 1988. Featuring a full QWERTY keyboard and the ability to run BASIC programs, it truly blurred the line between toy and computer. In fact from a technical standpoint it wasn’t far removed from early desktop computers, as it was powered by the same Zilog Z80 CPU found in the TRS-80 Model I.

By comparison, the Smart Start has more in common with a desktop electronic calculator. Even though it was released just two years prior to the PreComputer 1000, you can tell at a glance that it’s a far more simplistic device. That’s due at least in part to the fact that it was aimed at a younger audience, but surely the rapid advancement of computer technology at the time also played a part. Somewhat ironically, VTech did still at least attempt to make the Smart Start look like a desktop computer, complete with the faux disk drive on the front panel.

Of course, looks can be deceiving. While the Smart Start looks decidedly juvenile on the outside, that doesn’t mean there aren’t a few surprising technical discoveries lurking under its beige plastic exterior. There’s only one way to find out.

Continue reading “Teardown: VTech Smart Start” →

SCADA Security Hack Chat

July 12, 2021 by Dan Maloney 18 Comments

Join us on Wednesday, July 14 at noon Pacific for the SCADA Security Hack Chat with Éireann Leverett!

As a society, we’ve learned a lot of hard lessons over the last year and a half or so. But one of the strongest lessons we’ve faced is the true fragility of our infrastructure. The crumbling buildings and bridges and their tragic consequences are one thing, but along with attacks on the food and energy supply chains, it’s clear that our systems are at the most vulnerable as their complexity increases.

And boy are we good at making complex systems. In the United States alone, millions of miles of cables and pipelines stitch the country together from one coast to the other, much of it installed in remote and rugged places. Such far-flung systems require monitoring and control, which is the job of supervisory control and data acquisition, or SCADA, systems. These networks have grown along with the infrastructure, often in a somewhat ad hoc manner, and given their nature they can be tempting targets for threat actors.

Finding ways to secure such systems is very much on Éireann Leverett’s mind. As a Senior Risk Researcher at the University of Cambridge, he knows about the threats to our infrastructure and works to find ways to mitigate them. His book Solving Cyber Risk lays out a framework for protecting IT infrastructure in general. For this Hack Chat, Éireann will be addressing the special needs of SCADA systems, and how best to protect these networks. Drop by with your questions about infrastructure automation, mitigating cyber risks, and what it takes to protect the endless web of pipes and wires we all need to survive.

Our Hack Chats are live community events in the Hackaday.io Hack Chat group messaging. This week we’ll be sitting down on Wednesday, July 14 at 12:00 PM Pacific time. If time zones have you tied up, we have a handy time zone converter.

Hackaday Links: July 11, 2021

July 11, 2021 by Dan Maloney 5 Comments

Well, at least the acronym will stay the same. It looks like black is the new blue for Windows 11, as the BSOD screen gets its first makeover in years. It’s an admittedly minor change, since the on-screen text is virtually identical to the BSOD from recent versions of Windows 10, and the new death-knell even sports the same frowny-face emoji and QR code. Really, the white-on-black color scheme is the only major difference we can see — even the acronym will stay the same. It’s not really that newsworthy, we suppose, although it does make us miss the extremely busy BSODs from back in the Windows NT days.

As the semiconductor shortage continues, manufacturers are getting desperate to procure the parts they need to make their products. And if there’s one thing as certain as death and taxes, it’s that desperation provides opportunity to criminals. A thread over on EEVBlog details an encounter one company had with an alleged scammer, who sent an unsolicited offer to them for a large number of ordinarily hard-to-find microprocessors at a good price. Wisely, the company explored the offer in some depth and found that “Brian” (the representative who contacted them) is actually named Nick Martin and, according to an article on the Electronic Resellers Association International (ERAI) website, is apparently associated with a number of fraudulent operations. Their list of allegedly fraudulent deals made by Mr. Martin stretches back to 2018 and totals over $300,000 of ill-gotten gain.

Last year, friend-of-Hackaday and laser artist Seb Lee-Delisle spent a lot of time and effort getting together an amazing interactive laser light show for the night skies of cities in the UK. Laser Light City, with powerful lasers mounted on the tops of tall buildings, was a smashing success that brought a little cheer into what was an otherwise dreadful time. But we have to admit that the videos and other materials covering Laser Light City left us wanting more — something like that, with a far-flung installation on rooftops and the ability for audience members to control it all from their phone, really needs a deeper “how it works” treatment. Thankfully, Seb has released a video that dives into the nuts and bolts of the show, including a look at ludicrously powerful lasers with beams that can still be seen in broad daylight.

Continue reading “Hackaday Links: July 11, 2021” →

You Can’t Fix What You Can’t Measure

July 10, 2021 by Elliot Williams 13 Comments

Last year, as my Corona Hobby™, I took up RC plane flying. I started out with discus-launched gliders, and honestly that’s still my main love, but there’s only so much room for hackery in planes that are designed to be absolutely minimum weight and maximum performance; these are the kind of planes that notice an extra half gram in the tail. So I’ve also built a few crude workhorse planes — the kind of things that you could slap a 60 g decade-old GoPro on and it won’t even really notice. Some have ended their lives in trees, but most have been disassembled and reincarnated — the electronics live on in the next body.

The journey has been really fun. I’ve learned about aerodynamics, gotten an excuse to put together a 4-axis hot-wire CNC styrofoam cutter, and covered everything in sight with carbon fiber tow, which is cheaper than you might think but makes the plane space-age. My current workhorse has bolted on an IMU, GPS, and a minimal Ardupilot setup, though I have yet to really put it through its paces. What’s holding me back is the video link — it just won’t work reliably further than a few hundred meters, and I certainly don’t trust it to get out of line-of-sight.

My suspicion is that the crappy antennas I have are holding me back, which of course is an encouragement to DIY, but measuring antennas in the 5.8 GHz band is tricky. I’d love to just be able to buy one of the cheap vector analyzers that we’ve covered in the past — anyone can make an antenna when they can see what they’re doing — but they top out at 2.4 GHz or lower. No dice. I’m blind in 5.8 GHz.

Of course, I do have one way in, and that’s tapping into the received signal strength indicator (RSSI) of a dedicated 5.8 GHz receiver, and just testing antennas out in practice, but that only gives a sort of loose better-worse indication. More capacitance or more inductance? Plates closer together or further apart? Try it out and see, I guess, but it’s time-consuming.

Moral of the story: don’t take measurement equipment for granted. Imagine trying to build an analog circuit without a voltmeter, or to debug something digital without a logic probe. Sometimes the most important tool is the one that lets you see the problem in the first place.