Day: November 13, 2024

Landscape Motif Makes This E-Ink Weather Display Easy To Understand

November 13, 2024 by 3 Comments

True weather geeks will disagree, but there might be a better way to know how to dress for the day than divining what the weather will likely be from the current readings for temperature, pressure, humidity, and wind. Sure, the data will give you a good idea of where the weather is heading, but perhaps a quick visual summary such as the one offered by this pictorial landscape weather display is a better way to get out the door in the morning.

While many consumer weather stations incorporate some kind of graphical forecast for quick reference, [lds133] took a slightly different approach to forecasting. A cartoon landscape represents the day ahead, with various elements representing the coming weather scrolling across the display as time progresses. Trees are used to indicate wind direction and speed, with palm trees indicating south wind and pine trees winds from the north, and the taller the trees, the stronger the wind. The forest floor rises and falls with the expected temperature, the sun and moon appear at the proper time to indicate sunrise and sunset, and cloud icons are added when needed to show the degree of cloud cover. And because into each life a little rain must fall, animations show when you can expect rain or snow.

As for the electronics, if you think this would be a perfect application for an E-ink module, [lds133] agrees. The 296×128 pixel Waveshare display is the perfect aspect ratio for the job and provides nice, crisp icons. The display is updated every 15 minutes from the OpenWeather API by a Python program running on an ESP32 behind the scenes.

We’ve seen similar graphical forecast displays before, but we get it if that’s not your thing. Perhaps a more data-driven weather forecast will suit you better?

FLOSS Weekly Episode 809: Pi4J – Stable And Boring On The Raspberry Pi

November 13, 2024 by No comments

This week, Jonathan Bennett and David Ruggles chat with Frank Delporte about Pi4J, the friendly Java libraries for the Raspberry Pi, that expose GPIO, SPI, I2C and other IO interfaces. Why would anyone want to use Java for the Pi? And what’s changed since the project started? Listen to find out!

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Making Sense Of Real-Time Operating Systems In 2024

November 13, 2024 by 16 Comments

The best part about real-time OS (RTOS) availability in 2024 is that we developers are positively spoiled for choice, but as a corollary this also makes it a complete pain to determine what the optimal choice for a project is. Beyond simply opting for a safe choice like FreeRTOS for an MCU project and figuring out any implications later during the development process, it can pay off massively to invest some time up-front matching the project requirements with the features offered by these various RTOSes. A few years ago I wrote a primer on the various levels of ‘real-time’ and whether you may even just want to forego an RTOS at all and use a simple Big Loop™ & interrupt-based design.

With such design parameters in mind, we can then look more clearly at the available RTOS options available today, which is the focus of this article. Obviously it won’t be an exhaustive comparison, and especially projects like FreeRTOS have seen themselves customized to various degrees by manufacturers like ST Microelectronics and Espressif, among others. This also brings to the forefront less pleasant considerations, such as expected support levels, as illustrated by e.g. Microsoft’s Azure RTOS (formerly ThreadX) recently getting moved to the Eclipse Foundation as the Apache ThreadX open source project. On one hand this could make it a solid open-source licensed RTOS, or it could have been open sourced because Microsoft has moved on to something else and cleared out its cupboard.

Thus without further ado, let’s have a look at RTOSes in 2024 and which ones are worth considering, in my opinion.

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A Vintage Radiator Core, From Scratch

November 13, 2024 by 13 Comments

There are sadly few 1914 Dennis fire engines still on the road, so when the one owned by Imperial College in London needs a spare part, it can not be ordered from the motor factors and must be made from scratch. Happily, [Andy Pugh] is an alumnus with the required metalworking skills, so in the video below we see him tackling the manufacture of flattened brass tubes for its radiator core.

Forming a round tube to a particular shape is done by pulling it through a die whose profile gradually changes from round to the desired shape. We see him make a couple of tries at this, finally succeeding with one carefully designed to have a constant circumference. The use of CNC machining is something that wouldn’t have been available in the Dennis works in the early 20th century, so we can marvel at the skills of the machinists back then who made the original. Here in 2024 he makes a drawing rig with a geared chain drive suitable for larger scale production.

The video is both a fascinating look at tube drawing and a mind-cleansing piece of workshop observation, and we have to say we enjoyed watching it. If [Andy]’s name sounds familiar to you, this might be because this isn’t the first go he’s had at manufacturing vehicle parts.

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A Teletype By Any Other Name: The Early E-mail And Wordprocessor

November 13, 2024 by 24 Comments

Some brand names become the de facto name for the generic product. Xerox, for example. Or Velcro. Teletype was a trademark, but it has come to mean just about any teleprinter communicating with another teleprinter or a computer. The actual trademark belonged to The Teletype Corporation, part of Western Electric, which was, of course, part of AT&T. But there were many other companies that made teleprinters, some of which were very influential.

The teleprinter predates the computer by quite a bit. The original impetus for their development was to reduce the need for skilled telegraph operators. In addition, they found use as crude wordprocessors, although that term wouldn’t be used for quite some time.

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NASA Announces New Trials For In-Space Laser Welding

November 13, 2024 by 15 Comments

In-space manufacturing is a big challenge, even with many of the same manufacturing methods being available as on the ground. These methods include rivets, bolts, but also welding, the latter of which was first attempted fifty years ago by Soviet cosmonauts. In-space welding is the subject of a recently announced NASA collaboration. The main aspects to investigate are the effects of reduced gravity and varying amounts of atmosphere on welds.

The Soviets took the lead in space welding when they first performed the feat during the Soyuz-6 mission in 1969. NASA conducted their own welding experiments aboard Skylab in 1973, and in 1984, the first (and last) welds were made in open space during an EVA on the Salyut-7 mission. This time around, NASA wants to investigate fiber laser-based welding, as laid out in these presentation slides. The first set of tests during parabolic flight maneuvers were performed in August of 2024 already, with further testing in space to follow.

Back in 1996 NASA collaborated with the E.O. Paton Welding Institute in Kyiv, Ukraine, on in-space welding as part of the ISWE project which would have been tested on the Mir space station, but manifesting issues ended up killing this project. Most recently ESA has tested in-space welding using the same electron-beam welding (EBW) approach used by the 1969 Soyuz-6 experiment. Electron beam welding has the advantage of providing great control over the weld in a high-vacuum environment such as found in space.

So why use laser beam welding (LBW) rather than EBW? EBW obviously doesn’t work too well when there is some level of atmosphere, is more limited with materials and has as only major advantage that it uses less power than LBW. As these LBW trials move to space, they may offer new ways to create structure and habitats not only in space, but also on the lunar and Martian surface.

Featured image: comparing laser beam welding with electron beam welding in space. (Source: E. Choi et al., OSU, NASA)

Intuition About Maxwell’s Equations

November 13, 2024 by 10 Comments

You don’t have to know how a car engine works to drive a car — but you can bet all the drivers in the Indy 500 have a better than average understanding of what’s going on under the hood. All of our understanding of electronics hinges on Maxwell’s equations, but not many people know them. Even fewer have an intuitive feel for the equations, and [Ali] wants to help you with that. Of course, Maxwell’s gets into some hairy math, but [Ali] covers each law in a very pragmatic way, as you can see in the video below.

While the video explains the math simply, you’ll get more out of it if you understand vectors and derivatives. But even if you don’t, the explanations provide a lot of practical understanding

Understanding the divergence and curl operators is one key to Maxwell’s equations. While this video does give a quick explanation, [3Blue1Brown] has a very detailed video on just that topic. It also touches on Maxwell’s equations if you want some reinforcement and pretty graphics.

Maxwell’s equations can be very artistic. This is one of those topics where math, science, art, and history all blend together.

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