On March 8, 2014, Malaysia Airlines Flight 370 vanished. The crash site was never found, nor was the plane. It remains one of the most perplexing aviation mysteries in history. In the years since the crash, investigators have looked into everything from ocean currents to obscure radio phenomena to try and locate the plane. All have thus far failed to find the wreckage.
It was on July 2015 when a flaperon from the aircraft washed up on Réunion Island. It was the first piece of wreckage found, and it was hoped it could provide clues to the airliner’s final resting place. While it’s yet to reveal a final answer as to the aircraft’s fate, some of the ocean life living on it could help investigators need to find the plane. The picture is murky right now, but in an investigation where details are scarce, every little clue helps.
There are probably very few people on this globe who at some point in time haven’t heard the term ‘Higgs Boson’ zip past, along with the term ‘God Particle’. As during the 2010s the scientists at CERN were trying to find evidence for the existence of this scalar boson and with it evidence for the existence of the Higgs field that according to the Standard Model gives mass to gauge bosons like photons, this effort got communicated in the international media and elsewhere in a variety of ways.
Along with this media frenzy, the physicist after whom the Higgs boson was named also gained more fame, despite Peter Higgs already having been a well-known presence in the scientific community for decades by that time until his retirement in 1996. With Peter Higgs’ recent death after a brief illness at the age of 94, we are saying farewell to one of the big names in physics. Even if not a household name like Einstein and Stephen Hawking, the photogenic hunt for the Higgs boson ended up highlighting a story that began in the 1960s with a series of papers.
PhD students spend their time pursuing whatever general paths their supervisor has given them, and if they are lucky, it yields enough solid data to finally write a thesis without tearing their hair out. Sometimes along the way they result in discoveries with immediate application outside academia, and so it was for [Paul Bupe Jr.], whose work resulted in a rather elegant and simple bend sensor.
The original research came when shining light along flexible media, including a piece of transparent 3D printer filament. He noticed that when the filament was bent at a point that it was covered by a piece of electrical tape there was a reduction in transmission, and from this he was able to repeat the effect with a piece of pipe over a narrow air gap in the medium.
Putting these at regular intervals and measuring the transmission for light sent along it, he could then detect a bend. Take three filaments with the air-gap-pipe sensors spaced to form a Gray code, and he could digitally read the location.
He appears to be developing this discovery into a product. We’re not sure which is likely to be more stress, writing up his thesis, or surviving a small start-up, so we wish him luck.
The simple capacitor equivalent circuit taught in school
Inductors are more like a resistor in series with an ideal inductor, resistors can be inductors as well, and well, capacitors aren’t just simply a capacitance in a package. Little with electronics is as plain and simple in reality as basic theory would have you believe. [Tahmid Mahbub] was measuring an electrolytic capacitor with an LCR and noticed it measuring 19 uF despite the device being rated at 470 uF. This was because such parts are usually specified at low frequencies, and at a mere 100 kHz, it was measuring way out of the specification they were expecting. [Tahmid] goes into a fair bit of detail regarding how to model the equivalent circuit of a typical electrolytic capacitor and how to determine with a bit more accuracy what to expect.
An aluminium electrolytic capacitor is more like this
The basic equivalent circuit for a capacitor has a series resistance and inductance, which covers the connecting leads and any internal tabs on the plates. A large-valued parallel resistor models the leakage through the dielectric in series with the ideal capacitance, which is responsible for the capacitor’s self-discharge property. However, this model is still too simple for some use cases. A more interesting model, shown to the left, comprises a ladder of distributed capacitances and associated resistances that result in a progressively longer time-constant component as you move from C1 to C5. This resembles more closely the linear structure of the capacitor, with its rolled-up construction. This model is hard to use in any practical sense due to the need to determine values for the components from a physical part. Still, it is useful to understand why such capacitors perform far worse than you would expect from just a simple equivalent model that looks at the connecting leads and little else.
During the 1980s, a moral panic swept across the landscape with the mistaken belief that there were Satanic messages hidden in various games, books, and music that at any moment would corrupt the youth of the era and destroy society as we knew it. While completely unfounded, it turns out that there actually were some hidden messages in vinyl records of the time although they’d corrupt children in a different way, largely by getting them interested in computer science. [Dandu] has taken to collecting these historic artifacts, preserving the music and the software on various hidden recordings.
While it was possible to record only programs or other data to vinyl, much in the same way that cassette tapes can be used as a storage medium, [Dandu]’s research focuses mostly on records, tapes, and CDs which had data included alongside music. This includes not only messages or images, but often entire computer programs. In some cases these programs were meant to be used with the accompanying music, as was the case for The Other Side Of Heaven by Kissing The Pink with a program for the BBC Micro. Plenty of other contemporary machines are represented here too including the ZX Spectrum, Atari, Apple II, and the Commodore 64. The documentation extends through the CD era and even into modern music platforms like Spotify and Apple Music.
The process of extraction and recovery is detailed for each discovery, making it a comprehensive resource for retro computing enthusiasts stretching from the 80s to now. There are likely a few hidden pieces of data out there hidden in various antique storage media that [Dandu] hasn’t found yet, either. You could even make your own records with hidden programs provided you have some musical and programming talents, and a laser engraver for the record itself.
Imagine an electronics lab. If you grew up in the age of tubes, you might envision a room full of heavy large equipment. Even if you grew up in the latter part of the last century, your idea might be a fairly large workbench with giant boxes full of blinking lights. These days, you can do everything in one little box connected to a PC. Somehow, though, it doesn’t quite feel right. Besides, you might be using your computer for something else.
I’m fortunate in that I have a good-sized workspace in a separate building. My main bench has an oscilloscope, several power supplies, a function generator, a bench meter, and at least two counters. But I also have an office in the house, and sometimes I just want to do something there, but I don’t have a lot of space. I finally found a very workable solution that fits on a credenza and takes just around 14 inches of linear space.
How?
How can I pack the whole thing in 14 inches? The trick is to use only two boxes, but they need to be devices that can do a lot. The latest generation of oscilloscopes are quite small. My scope of choice is a Rigol DHO900, although there are other similar-sized scopes out there.
If you’ve only seen these in pictures, it is hard to realize how much smaller they are than the usual scopes. They should put a banana in the pictures for scale. The scope is about 10.5″ wide (265 mm and change). It is also razor thin: 3″ or 77 mm. For comparison, that’s about an inch and a half narrower and nearly half the width of a DS1052E, which has a smaller screen and only two channels.
A lot of test gear in a short run.
If you get the scope tricked out, you’ve just crammed a bunch of features into that small space. Of course, you have a scope and a spectrum analyzer. You can use the thing as a voltmeter, but it isn’t the primary meter on the bench. If you spend a few extra dollars, you can also get a function generator and logic analyzer built-in. Tip: the scope doesn’t come with the logic analyzer probes, and they are pricey. However, you can find clones of them in the usual places that are very inexpensive and work fine.
There are plenty of reviews of this and similar scopes around, so I won’t talk anymore about it. The biggest problem is where to park all the probes. Continue reading “The Short Workbench”→
With the recently introduced SecOC (Secure Onboard Communication) standard, car manufacturers seek to make the CAN bus networks that form the backbone of modern day cars more secure. This standard adds a MAC (message authentication code) to the CAN messages, which can be used to validate that these messages come from a genuine part of the car, and not from a car thief or some third-party peripheral.
To check that it isn’t possible to circumvent SecOC, [Willem Melching] and [Greg Hogan] got their hands on the power steering (EPS) unit of a Toyota RAV4 Prime, as one of the first cars to implement this new security standard.
The 2021 Toyota RAV4 Prime’s power steering unit on the examination bench. (Credit: Willem Melching)
As noted by [Willem], the ultimate goal is to be able to run the open source driver assistance system openpilot on these SecOC-enabled cars, which would require either breaking SecOC, or following the official method of ‘rekeying’ the SecOC gateway.
After dumping the firmware of the EPS Renesas RH850/P1M-E MCU via a voltage fault injection, the AES-based encryption routines were identified, but no easy exploits found in the main application. This left the bootloader as the next target.
Ultimately they managed to reverse-engineer the bootloader to determine how the update procedure works, which enabled them to upload shellcode. This script then enabled them to extract the SecOC keys from RAM and send these over the CAN bus. With these keys the path is thus opened to allow any device to generate CAN messages with valid SecOC MACs, effectively breaking encryption. Naturally, there are many caveats with this discovery.
