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Hackaday Links: September 29, 2024

September 29, 2024 by 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.

Continue reading “Hackaday Links: September 29, 2024” →

Thinkpad 13 Gets NVMe Support With Three Jumpers

September 29, 2024 by 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 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 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.

Curing CRT Cataracts Freshens Up Retro Roundy TVs

September 29, 2024 by 12 Comments

It’s been a long time since the family TV has had a CRT in it, and even longer since that it was using what was basically an overgrown oscilloscope tube. But “roundies” were once a thing, and even back in the early 80s you’d still find them in living rooms on TV repair calls, usually sporting a characteristic and unsightly bullseye discoloration.

Fast-forward a few decades, and roundy TVs have become collectible enough that curing their CRT cataracts is necessary for restorationists like [shango066], a skill he demonstrates in the video below. The defect comes from the composite construction of CRTs — a safety feature added by television manufacturers wisely concerned with the safety aspects of putting a particle accelerator with the twin hazards of high vacuum and high voltage in the family home. The phosphor-covered face of the tube was covered by a secondary glass cover, often tinted and frosted to improve the admittedly marginal viewing experience. This cover was often glued in place with an epoxy resin that eventually oxidized from the edges in, making the bullseye pattern.

The remedy for this problem? According to [shango066], it’s heat, and plenty of it. After liberating the tube from the remarkably clean TV chassis, he took advantage of a warm summer’s day and got the tube face cooking under a black plastic wrap. Once things were warmed up, more heat was added to really soften the glue; you can easily see the softening progress across the face of the tube in the video below. Once softened, gentle prying with wooden chopsticks completes the job of freeing the safety lens, also in remarkably good shape.

With the adhesive peeled off in an oddly satisfying manner, all that’s left is a thorough cleaning and gluing the lens back on with a little silicone sealant around the edges. We’d love to see the restored TV in operation, but that’s left to a promised future video. In the meantime, please enjoy a look at the retro necessities TV owners depended on in the good old days, which really weren’t all that good when you get down to it.

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Internet Connected TI-84 To Cut Your Academic Career Short

September 29, 2024 by 22 Comments

In an educational project with ethically questionable applications, [ChromaLock] has converted the ubiquitous TI-84 calculator into the ultimate cheating device.

The foundation of this hack lies in the TI-84’s link protocol, which has been a mainstay in calculator mods for years. [ChromaLock] uses this interface to connect to a tiny WiFi-enabled XIAO ESP32-C3 module hidden in the calculator. It’s mounted on a custom PCB with a simple MOSFET-based level shifting circuit, and slots neatly into a space on the calculator rear cover. The connecting wires are soldered directly to the pads of the 2.5 mm jack, and to the battery connections for power.

But what does this mod do? It connects your calculator to the internet and gives you a launcher with several applets. These allow you to view images badly pixelated images on the TI-84’s screen, text-chat with an accomplice, install more apps or notes, or hit up ChatGPT for some potentially hallucinated answers. Inputting long sections of text on the calculator’s keypad is a time-consuming process, so [ChromaLock] teased a camera integration, which will probably make use of newer LLMs image input capabilities. The ESP32 doesn’t handle all the heavy lifting, and needs to connect to an external server for more complex interfaces.

To prevent pre-installed programs from being used for cheating on TI-84s, examiners will often wipe the memory or put it into test mode. This mod can circumvent both. Pre-installed programs are not required on the calculator to interface with the hardware module, and installing the launcher is done by sending two variables containing a password and download command to the ESP32 module. The response from the module will also automatically break the calculator out of test mode.

We cannot help but admire [ChromaLock]’s ingenuity and polished implementation, and hopefully our readers are more interested in technical details than academic self-sabotage. For those who need even more capability in their calculator, we’d suggest checking out the NumWorks. Continue reading “Internet Connected TI-84 To Cut Your Academic Career Short” →

An ESP32 Delivers Perfect Slot Car Control

September 28, 2024 by 5 Comments

If your memory of slot cars as a childhood toy is of lightweight controllers with wire-wound rheostats inside, then you’re many years behind the state of the art when it comes to competitive slot car racing. In that world the full force of modern electronics has been brought to keeping the car on the road, and as an example here’s [Maker Fabio] with a cutting edge controller that has an ESP32 at its heart.

It’s obvious that a huge amount of attention has gone into both the physical design of the unit and its software, and the result speaks for itself. The trigger sits on a proper bearing, and the sensor is a Hall-effect device on the PCB. The firmware was written in the Arduino IDE, and through the trigger and a rotary encoder all of its options can be configured on a small OLED display. Individual settings can be configured for each car, and we’re treated to a full explanation of this in the video.

We are told that the files for both software and hardware will be released in due course, as this is still a work in progress for the moment. The video meanwhile provides ample demonstration, so we look forward to the release.

It’s a surprise to find relatively few projects from the slot car world on these pages, given the amount of potential there is in them for electronic improvement. Here’s one from a few years ago though.

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