Author: Jenny List

3250 Articles

Making An Aircraft Wing Work For An Audience

January 31, 2024 by 3 Comments

Many of us will have sat and idly watched the flaps and other moving parts of an airliner wing as we travel, and it’s likely that most of you will know the basics of how an aircraft wing works. But there’s more to an aircraft wing than meets the eye, which is why the Aerospace Bristol museum has an Airbus A320 wing on display. [Chris Lymas] was part of the team which turned a surplus piece of aircraft into an interactive and working exhibit, and he told the Electromagnetic Field audience all about it in his talk Using Arduinos to Resurrect an Airliner Wing.

The talk starts with an explanation of how a variable surface wing works, and then starts to talk about the control systems employed. We’re struck with the similarity to industrial robots, in that this is a a powerful and thus surprisingly dangerous machine to be close to. The various moving surfaces are moved by a series of shafts and gearboxes, driven by a DC motor. Running the show is an Arduino Mega, which has enough interfaces for all the various limit switches.

It’s fascinating to see how the moving parts in an airliner wing work up close, and we’re impressed at the scale of the parts which keep us safe as we fly. Take a look, the video is below the break.

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A Basic USB-C Primer

January 30, 2024 by 32 Comments

Over the last five years or so there has been a quiet take-over of the ports on laptops, phones, and other devices, as a variety of older ports as well as the familiar USB A and micro USB sockets have been replaced by the now-ubiquitous USB-C port. It’s a connector which can do so many things, so many in fact that it bears a handy explanation. The Electromagnetic Field 2022 hacker camp has been quietly uploading videos of its talks, and a recent one has [Tyler Ward] explaining the intricacies of the interface.

Many of you will be familiar with XKCD number 927 which makes a joke about proliferating connector standards, and it’s evident that USB-C is a rare case of a connector which bucks the trend of simply making another standard, and has instead created something with which it makes sense to replace what went before. We learn about the intricacies of inter-device communications and USB-PD, and the multiple high-speed connection  lanes shoehorned into it. That one small connector can plug into a laptop and provide power, USB peripherals including network, and display, is nothing short of amazing. Take a look at the video below the break, and if you’re interested in diving deeper, have a look at our colleague [Arya Voronova]’s USB-C for hackers series.

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A Complete Exchange From Scratch For Your Rotary Dial Phones

January 29, 2024 by 12 Comments

Such has been the success of the mobile phone that in many places they have removed the need for wired connections, for example where this is being written the old copper connection can only be made via an emulated phone line on an internet router. That doesn’t mean that wired phones are no longer of interest to a hardware hacker though, and many of us have at times experimented with these obsolete instruments. At the recent 37C3 event in Germany, [Hans Gelke] gave a talk on the analog exchange he’s created from scratch.

The basic form of the circuit is built around a crosspoint switch array, with interfaces for each line and a Raspberry Pi to control it all. But that simple description doesn’t fully express its awesomeness, rather than hooking up a set of off-the-shelf modules he’s designed everything himself from scratch. His subscriber line interface circuit uses a motor controller to generate the bell signal, his analogue splitter has an op-amp and a transistor, and his crosspoint array is a collection of JFETs. Having dabbled in these matters ourselves, it’s fascinating to see someone else making this work. Video below the break.

Have an analogue phone but nowhere to use it? Bring it to a hacker camp!

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A Mouse Becomes A Camera

January 29, 2024 by 24 Comments

If your pointing device is a mouse, turn it over. The chances are you’ll see a red LED light if you’re not seriously old-school and your mouse has a ball, this light serves as the illumination for a very simple camera sensor. The mouse electronics do their thing by looking for movement in the resulting image, but it should be possible to pull out the data and repurpose the sensor as a digital camera. [Doctor Volt] has a new video showing just that with the innards of a Logitech peripheral.

The mouse contains a microcontroller and the camera part, which fortunately has an SPI interface. The correct register to query the sensor information was deduced, and as if my magic, an image appeared. An M12 lens provided focus with a handy 3D printed mount, and the board went back into the mouse case as a housing. The pictures have something of the Game Boy camera about them, being low-res and monochrome, but it’s still a neat hack.

If you’d like to give it a go you can find the code in a GitHub repository. You might find it worth finding a gaming mouse though, for the much higher resolution sensor.

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A Vintage Monitor Lives Again With A New Heart

January 29, 2024 by 25 Comments

Aside from keeping decades-old consumer-grade computing hardware working, a major problem for many retrocomputing enthusiasts lies in doing the same for vintage monitors. Whether your screen is a domestic TV or a dedicated monitor, the heat and voltage stress of driving a CRT made these devices significantly less reliable than many of their modern-day counterparts. [Adrian’s Digital Basement] has a worn-out and broken Commodore 1701 monitor, which he’s brought back to life with a modern circuit board and a CRT transplant.

Following on from a previous project, he’s using a replacement board sold as a repair option for CRT TVs on AliExpress. The Commodore monitor has its board on a metal chassis which takes the replacement with a bit of modification. He doesn’t say where the new CRT came from, but we’re guessing it was a late model TV as CRTs made over the last few decades are more interchangeable than might be expected. There’s a moment of mild dodginess as he makes a voltage doubler to run the 220 V board from 120 V with a pair of large electrolytic capacitors hot glued in place, but otherwise it’s a success.

At the end of it all after some testing and set-up he has a Commodore monitor with a new heart and multi-standard support. Is it really a Commodore monitor though, or should it have been repaired? It’s a difficult one to answer, but we’d suggest that CRT monitor repair is less easy today than it used to be because many of the parts are now difficult to find. If it saves at least some of the original from the dumpster it’s better than doing nothing. We wonder how long these upgrades will remain possible as even with Chinese plants making these boards and a handful of CRT TVs still appearing on AliBaba it’s clear that CRTs are at the very end of their life.

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Flux, From Scratch

January 29, 2024 by 53 Comments

Soldering flux is (or at least, should be) one of the ubiquitous features of any electronics bench. It serves the purpose of excluding oxygen from a solder joint as it solidifies, and in most cases its base is derived from pine rosin. Most of us just buy flux, but [pileofstuff] is having a go at making his own.

He starts with a block of rosin and a couple of different solvents. Isopropanol we’re happy with, but perhaps using methanol for something to be vaporized within breathing distance isn’t something we’d do. At about 25% rosin to solvent ratio the result is a yellow liquid flux, which he tests against some commercial fluxes. The result is a reasonable liquid flux, something which perhaps shouldn’t be too much of a surprise, and is a handy piece of information to store away should we ever be MacGuyver-like stuck in a pine forest with a need to save the day with electronics.

It would be interesting to try the same technique but with a solvent selected to soften the rosin for a paste flux, and perhaps any chemists among our readership could enlighten us about just what rosin is beside the heavy fractions left after extracting the volatiles from pine resin.

In the past we’ve taken a close look at how solder really works.

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Bringing An IBM Butterfly Laptop Back From The Dead

January 28, 2024 by 8 Comments

Among all the laptops produced over the last few decades, there is one which rises above the rest and which has retained an appeal long after its meager computing resources became obsolete. It’s the IBM 701c, the famous “Butterfly” laptop, whose fold-out keyboard still gives it star  quality, and [John Graham-Cumming] has documented the restoration of one from the tattered remains of two scrap examples.

The two laptops in question were someone else’s never-started project, and were in a sorry state. The flexible cables were in poor condition, and the 1990s Ni-MH batteries had leaked and damaged both circuits and case. We were unaware that NiMH leakage could damage plastic, but the parts of these machines were significantly damaged.

One had a working mainboard, the other a working modem card. One keyboard was in pretty bad shape, the other was complete. Of the pair there was a double super twisted nematic (DSTN) display and a more contemporary thin film transistor (TFT) panel. Be thankful if you have never had to use a DSTN laptop, as they were truly awful. From this pile of parts a working machine could be made, and with a new CMOS battery, that cable repair, and a repaint, he was ready. Or at least, as he says, ready for 1995.

This isn’t the first 701c restoration we’ve seen, and within reason, it’s even possible to give them a retro processor upgrade.