Inside The F-4 Attitude Indicator

September 30, 2024 by Al Williams 10 Comments

[Ken] recently obtained an attitude indicator—sometimes called an artificial horizon—from an F-4 fighter jet. Unlike some indicators, the F-4’s can rotate to show pitch, roll, and yaw, so it moves in three different directions. [Ken] wondered how that could work, so, like any of us, he took it apart to find out.

With the cover off, the device is a marvel of compact design. Then you realize that some of the circuit is inside the ball, so there’s even more than it appears at a quick glance. As you might have guessed, there are two separate slip rings that allow the ball to turn freely without tangling wires. Of course, even if you don’t tangle wires, getting the ball to reflect the aircraft’s orientation is an exercise in control theory, and [Ken] shows us the servo loop that makes it happen. There’s a gyroscope and synchros—sometimes known by the trade name selsyn—to keep everything in the same position.

You have to be amazed by the designers of things like this. Sophisticated both electrically and mechanically, rugged, compact, and able to handle a lot of stress. Good thing it didn’t have to be cheap.

We’ve seen inside an ADI before. If you want to make any of this look simple, check out the mechanical flight computers from the 1950s.

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Shoot Smooth Video From Your Phone With The Syringe Slider

September 29, 2024 by Donald Papp 5 Comments

We love the idea [Btoretsukuru] shared that uses a simple setup called the Syringe Slider to take smoothly-tracked video footage of small scenes like model trains in action. The post is in Japanese, but the video is very much “show, don’t tell” and it’s perfectly clear how it all works. The results look fantastic!

The device consists of a frame that forms a sort of enclosed track in which one’s mobile phone can slide horizontally. The phone butts up against the plunger of an ordinary syringe built into the frame. As the phone is pushed along, it depresses the plunger which puts up enough resistance to turn the phone’s slide into a slow, even, and smooth glide. Want to fine-tune the resistance and therefore the performance? Simply attach different diameter tips to the syringe.

The results speak for themselves, and it’s a fantastically clever bit of work. There are plenty of DIY slider designs (some of which get amazingly complex) but they are rarely small things that can be easily gotten up close and personal with small subjects like mini train terrain.

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Some SPI Flash Chip Nuances Worth Learning

September 29, 2024 by Arya Voronova 13 Comments

Some hackers have the skills to help us find noteworthy lessons in even the most basic of repairs. For instance, is your computer failing to boot? Guess what, it could just be a flash chip that’s to blame — and, there’s more you should know about such a failure mode. [Manawyrm] and [tSYS] over at the Kittenlabs blog show us a server motherboard fix involving a SPI flash chip replacement, and tell us every single detail we should know if we ever encounter such a case.

They got some Gigabyte MJ11-EC1 boards for cheap, and indeed, one of the BIOS chips simply failed — they show you how to figure that one out. Lesson one: after flashing a SPI chip, remember to read back the image and compare it to the one you just flashed into it! Now, you might be tempted to take any flash chip as a replacement, after all, many are command-compatible. Indeed, the duo crew harvested a SPI chip from an ESP32 board, the size matched, and surely, that’d suffice.

That’s another factor you should watch out for. Lesson two is to compare the SPI flash commands being used on the two chips you’re working with. In this case, the motherboard would read the BIOS alright and boot just fine, but wasn’t able to save the BIOS settings. Nothing you couldn’t fix by buying the exact chip needed and waiting for it to arrive, of course! SPI flash command sets are fun and worth learning about — after all, they could be the key to hacking your “smart” kettle. Need a 1.8 V level shifter while flashing? Remember, some resistors and a NPN transistor is more than enough.

Hackaday Links: September 29, 2024

September 29, 2024 by Dan Maloney 16 Comments

There was movement in the “AM Radio in Every Vehicle Act” last week, with the bill advancing out of the US House of Representatives Energy and Commerce Committee and heading to a full floor vote. For those not playing along at home, auto manufacturers have been making moves toward deleting AM radios from cars because they’re too sensitive to all the RF interference generated by modern vehicles. The trouble with that is that the government has spent a lot of effort on making AM broadcasters the centerpiece of a robust and survivable emergency communications system that reaches 90% of the US population.

The bill would require cars and trucks manufactured or sold in the US to be equipped to receive AM broadcasts without further fees or subscriptions, and seems to enjoy bipartisan support in both the House and the Senate. Critics of the bill will likely point out that while the AM broadcast system is a fantastic resource for emergency communications, if nobody is listening to it when an event happens, what’s the point? That’s fair, but short-sighted; emergency communications isn’t just about warning people that something is going to happen, but coordinating the response after the fact. We imagine Hurricane Helene’s path of devastation from Florida to Pennsylvania this week and the subsequent emergency response might bring that fact into focus a bit.

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Thinkpad 13 Gets NVMe Support With Three Jumpers

September 29, 2024 by Arya Voronova 17 Comments

Hardware restrictions can be unreasonable, and at times, it can be downright puzzling just how arbitrary they are. Such is the case with the Lenovo ThinkPad 13 — it’s got a M.2 M-key socket, yet somehow only supports SATA SSDs in it, despite the CPU being new enough to support both SATA and NVMe effortlessly. [treble] got one of those laptops from a recycler, and decided to figure out just what this laptop’s deal is.

Armed with schematics, she and her friend looked at the M.2 implementation. The slot’s schematic sure looked ready to support either kind of drive, a surprising find. Here’s the catch — Lenovo only populated components for SATA drive support. All you need to switch from SATA to NVMe support is three magnet wire jumpers, or zero-ohm 0402 resistors, and voila; you can now use the significantly cheaper kind of M.2 drives in your ThinkPad.

All is documented, and [treble] even mentions that you could increase the link speed by adding more PCIe lane capacitors that Lenovo, again, left unsoldered. UEFI already has the modules needed to boot from NVMe, too – it’s an outright upgrade for your laptop with just a soldering iron’s touch required, and a reminder that proprietary tech will screw you over for entirely arbitrary reasons. Now, it’s not just laptops you can upgrade with a few resistors — same goes for certain electric cars.

First Tentative Sales Of Tandem Perovskite-Silicon PV Panels

September 29, 2024 by Maya Posch 18 Comments

To anyone who has spent some time in photovoltaic (PV) power circles, the word ‘perovskite’ probably sounds familiar. Offering arguably better bandgap properties than traditional silicon cells, perovskite-based PV panels also promise to be cheaper and (literally) more flexible, but commercialization has been elusive. This is something which Oxford PV seeks to change, with the claim that they will be shipping the first hybrid perovskite-silicon panels to a US customer.

Although Oxford PV prefers to keep the details of their technology classified, there have been decades of research on pure perovskite PV cells as well as tandem perovskite-silicon versions. The reason for the tandem (i.e. stacked) construction is to use more of the solar rays’ spectrum and total energy to increase output. The obvious disadvantage of this approach is that you need to find ways to make each layer integrate in a stable fashion, with ideally the connecting electrodes being transparent. A good primer on the topic is found in this 2021 review article by [Yuanhang Cheng] and [Liming Ding].

The primary disadvantage of perovskites has always been their lack of longevity, with humidity, UV irradiation, temperature and other environmental factors conspiring against their continued existence. In a 2022 study by [Jiang Liu] et al. in Science it was reported that a perovskite-silicon tandem solar cell lost about 5% of its initial performance after 1,000 hours. A 2024 study by [Yongbin Jin] et al. in Advanced Materials measured a loss of 2% after approximately the same timespan. At a loss of 2%/1,000 hours, the perovskite layer would be at 50% of its initial output after 25,000 hours, or a hair over 2.85 years.

A quick glance through the Oxford PV website didn’t reveal any datasheets or other technical information which might elucidate the true loss rate, so it would seem that we’ll have to wait a while longer on real data to see whether this plucky little startup has truly cracked the perovskite stability issue.

Top image: Summary of tandem perovskite-silicon solar cell workings. (Credit: Yuanhang Cheng, Liming Ding, SusMat, 2021)

Seven Day Movement Makes A Rubbish Clock

September 29, 2024 by Jenny List 10 Comments

We see a lot of clocks here at Hackaday. Some of them are better than others, but this one from [John Graham-Cumming] is definitely a rubbish clock. It performs the simple yet vital task of keeping track of which day is which when it comes to trash collection.

The big revelation for us from this project is that the standard plastic battery clock mechanism which you’ll no doubt be familiar with from many cheap clocks can also be bought with gearing for a weekly rather than daily revolution. The physical hack is therefore a pretty simple one of mounting the movement with a single hand over a face showing the waste collections, and the write-up goes into more depth about the code for creating custom SVG clock faces. We’re already thinking of interesting stuff that can be done with one of these movements.

Meanwhile, we like this clock, but it’s certainly not the first trash indicator we’ve seen.