The humble USB-C port has brought us so many advantages over its USB ancestors, one of which is as a handy display output for laptops. Simply add an inexpensive adapter and you can hook up everything from a mobile phone upwards to an HDMI display or projector. There’s a snag though, merely having USB-C is not enough as the device has to support the display feature. It’s a problem [Gunnar Wolf] had to face with a Lenovo ARM laptop, and his solution is unexpected. Instead of an adapter, he’s used a Raspberry Pi 3 and some software tricks.
The obvious route to an off-board Pi mirroring onboard video is to use VNC, which he tried but found wanting due to lagginess. As a user of the Wayland compositor he found he could instead use wf-recorder and send its output to a stream, and thus capture his screen in a way that the Pi could read over the network. It’s not quite as convenient a solution as a pure-hardware adapter, but at least it allowed him to share the screen.
It’s surprising how often we find projects needing to mirror the display of a computer using what hardware is to hand, at least this one is more elegant than some others.
As we gear up for a summer in the field, or more accurately in a series of fields, it’s time to turn our attention towards Eastnor Castle in the Western English county of Herefordshire, venue for the upcoming Electromagnetic Field hacker camp. Sadly we’ve got no badge to tease you with, but they’ve released a list of the talks that will fill their schedule. There are so many to choose from, we can only mention a few in this article.
One feature of this camp we’re very interested in will be CuTEL, a wired copper telephone network on the field. We’ll be taking along our trusty GPO 746 to be part of it of course, but for those without one, there’s [Matthew Harrold]’s talk on building a copper telephone network in a field.
Our cursory scan of the list finishes up with [Alistair MacDonald] on how not to start a hackerspace. We’ve seen our fair share of hackerspace drama over the years, so whether this one causes pain for ex-hackerspace-directors or not, it promises to be informative for anyone in the hackerspace world.
When a treasure of retrotechnology fails to work, the natural next step is to have a go at repairing it. [Adam Wilson] found himself in this position when he acquired a 1974 Sinclair Cambridge Scientific calculator, and his progress with the device makes for an interesting read.
First up is something of value to all old Sinclair enthusiasts, he’s found a solution to the original battery connectors being prone to failure. A couple of parts stocked by RS can be used as replacements, which should save quite a lot of Sinclairs with crusty connectors.
Saving the connectors should have fixed the calculator, but only served to reveal that it had an electronic fault. Some detective work traced this to the power supply, which is a small switching circuit. The 1974 chip and associated coil had both failed, which rather drew the project to a halt. A second repair-or-spares Cambridge Scientific was sourced, and by good luck it happened to have a working PCB. So [Adam] got a working calculator, and we hope he’ll succumb to the temptation to shoehorn in a PSU from 2022 to get the other one working.
A problem facing architects when designing complex three-dimensional structures lies in their joints, which must be strong enough to take the loads and vector forces applied by the structure, yet light enough not to dominate it. Many efforts have been made to use generative design techniques or clever composites to fabricate them, but as Dezeen reports, a team at MIT are exploring an unexpected alternative in the form of naturally occurring tree forks.
The point at which a tree branch forks from its trunk is a natural composite material formed of an interlocking mesh of wood grain fibres. Timber processors discard these parts of the tree as they interfere with the production of smooth timber, but the same properties that make them support the weight of a branch are it seems perfect for the architects’ needs.
The clever part of the MIT team’s work lies in scanning and cataloguing a library of forks, allowing them to be matched from the database to vertices in an architectural design. The forks are subject to minimal machining before being incorporated into the structure, and to prove it the MIT folks have made a test structure. It’s not uncommon to see medieval barns or half-timbered houses using curved pieces of wood in their natural shapes, so it’s not surprising to see that this 21st century innovation isn’t an entirely new technique.
The bane of life for anyone who possesses a well-used pile of spanners is the humble nut and bolt. Durable and easy to fasten, over our lifetimes we must screw and unscrew them by the million. When they do their job they’re great, but too often they seize up solid, or more alarmingly, gradually undo themselves over time due to vibration or thermal stress. There are a host of products such as locking nuts or thread sealant to deal with this problem, but the Fraunhofer Institute have an idea which might just remove the worry surrounding important fastenings. Their work has resulted in a solar-powered bolt with an embedded sensor that phones home when the connection loosens, allowing an engineer to be dispatched with a spanner to tighten it up.
The sensor itself is a washer which reports the force placed upon it, when this reduces an alert is sent. Communication is via Fraunhofer’s own MIoTy low-power wide-area network (LPWAN) protocol, but we’d imagine that one of the many competitor technologies could also serve.
This is an interesting idea that could no doubt result in targeted maintenance catching faulty fastenings early and averting disaster in the infrastructure projects such as bridges and wind turbines that they mention. We worry slightly though, because these types of structures have lives not in the few years of most tech products but in centuries. Will an IoT bolt head sensor still be phoning home in a few decades time, or will the system rely on old bolts being replaced at regular intervals of a decade? It’s not unknown for disasters to be the result of failures in fastenings a century old, so we sincerely hope that authorities in charge of whatever bridge relies on these won’t be tempted to skimp on their replacements. Perhaps a guy with a spanner every few years might be a more dependable option.
Watching television today is a very different experience from that which our parents would have had at our age, where we have high-definition digital on-demand streaming services they had a small number of analogue channels serving linear scheduled broadcasting. A particular film coming on TV could be a major event that it was not uncommon for most of the population to have shared, and such simple things as a coffee advert could become part of our common cultural experience. Behind it all was a minor miracle of synchronised analogue technology taking the signal from studio to living room, and this is the subject of a 1952 Coronet film, Television: How It Works! Sit back and enjoy a trip into a much simpler world in the video below the break.
Production values for adverts had yet to reach their zenith in the 1950s.
After an introduction showing the cultural impact of TV in early-50s America there’s a basic intro to a cathode-ray tube, followed by something that may be less familiar to many readers, the Image Orthicon camera tube that formed the basis of most TV signals of that era.
It’s written for the general public, so the scanning raster of a TV image is introduced through the back-and-forth of reading a book, and then translated into how the raster is painted on the screen with the deflection coils and the electron gun. It’s not overly simplified though, for it talks about how the picture is interlaced and shows how a synchronisation pulse is introduced to keep all parts of the system working together.
A particularly fascinating glimpse comes in a brief mention of the solid copper co-axial cable and overland microwave links used to transmit TV signals across country, these concrete towers can still be seen today but they no longer have the colossal horn antennas we can see in the film.
A rather obvious omission in this film is the lack of any mention of colour TV, as while it would be late 1953 before the NTSC standard was formally adopted and early 1954 before the first few colour sets would go on sale. Colour TV would have been very much the Next Big Thing in 1952, but with no transmissions to watch and a bitter standards war still raging between the field-sequential CBS system and RCA’s compatible dot-sequential system that would eventually evolve into the NTSC standard it’s not surprising that colour TV was beyond the consumer audience of the time.
Thus we’re being introduced to the 525-line standard which many think of as NTSC video, but without the NTSC compatible colour system that most of us will be familiar with. The 525-line analogue standard might have disappeared from our living rooms some time ago, but as the last few stations only came off-air last year we’d say it had a pretty good run.
A couple of years ago, Hackaday published an article, “Electric Vehicles Continue the Same Wasteful Mistakes That Limit Longevity“, in which we took a look at the way the car industry, instead of taking the move to electric traction as an opportunity to simplify their products, was instead making their electric offerings far more complex. It touched a nerve and received a very large comment volume, such that now it is our 19th most commented story of all time.
It’s something brought back to the fore by seeing a The Drive piece bemoaning the evolution of the automobile as a software receptacle governed by end-user licenses rather than a machine under the control of its owner. In turn that’s posed the question: Just what do you really need for a car, and what is superfluous? Time to provide an answer to that question, so here it is: a minimal motoring manifesto. Continue reading “A Minimal Motoring Manifesto”→
