Free And Open E-Reader From The Ground Up

July 17, 2024 by Bryan Cockfield 21 Comments

Although ebooks and e-readers have a number of benefits over reading an analog paper book as well as on more common electronic devices like tablets, most of them are locked behind proprietary systems like Kindle which make it difficult to take control over your electronic library. While there are a few off-brand e-readers that allow users to take a bit of control back and manually manage their files and libraries, there are few options for open-source solutions. This project aims to provide not only a free and open e-reader from the hardware to the software, but also a server to host a library as well.

The goal of most of the build is to keep everything as FLOSS as possible including the hardware, which is based on a Raspberry Pi compute module. The display comes from Good Display, which includes a built-in light and a touchscreen. There’s a lithium battery to power the tablet-like device with a number of support chips to charge it, handle the display, and interface with the Pi. On the software side, the system uses MuPDF which has support for most ebook file types while the server side is based on Calibre and the Open Publication Distribution System.

A subsection of the build log discusses a lot of how the code works for those looking to build their own similar system based on this project. The project code is even hosted on GitLab, a more FLOSS-y version of GitHub. Free and open ebook readers have been a goal of a number of builders for some time now, as we’ve seen projects going back at least a few years now and others that hope to make the Kindle hardware a little more open instead.

Las Vegas’ Sphere: Powered By Nvidia GPUs And With Impressive Power Bill

July 17, 2024 by Maya Posch 51 Comments

A daytime closeup of the LED pucks that comprise the exosphere of the Sphere in Paradise, Nevada (Credit: Y2kcrazyjoker4, Wikimedia)

As the United States’ pinnacle of extravaganza, the Las Vegas Strip and the rest of the town of Paradise are on a seemingly never-ending quest to become brighter, glossier and more over the top as one venue tries to overshadow the competition. A good example of this is the ironically very uninspiredly named Sphere, which has both an incredibly dull name and yet forms a completely outrageous entertainment venue with a 54,000 m² (~3.67 acre) wrap-around interior LED display (16 x 16K displays) and an exterior LED display (‘Exosphere’) consisting out of 1.23 million LED ‘pucks’. Although opened in September of 2023, details about the hardware that drives those displays have now been published by NVidia in a recent blog post.

Driving all these pixels are around 150 NVidia RTX A6000 GPUs, installed in computer systems which are networked using NVidia BlueField data processing units (DPUs) and NVidia ConnectX-6 NICs (up to 400 Gb/s), with visual content transferred from Sphere Studios in California to the Sphere. All this hardware uses about 45 kW of power when running at full blast, before adding the LED displays and related hardware to the total count, which is estimated to be up to 28 MW of power and causing local environmentalists grief despite claims by the owner that it’ll use solar power for 70% of the power needs, despite many night-time events. Another item that locals take issue with is the amount of light pollution that the exterior display adds.

Although it’s popular to either attack or defend luxurious excesses like the Sphere, it’s interesting to note that the state of Nevada mostly gets its electricity from natural gas. Meanwhile the 2.3 billion USD price tag for the Sphere would have gotten Nevada 16.5% of a nuclear power station like Arizona’s Palo Verde (before the recurring power bill), but Palo Verde’s reactor spheres are admittedly less suitable for rock concerts.

Office Supplies Make Math Sculptures If You Know What You’re Doing

July 17, 2024 by Lewin Day 7 Comments

Ever been fiddling around at your desk in the office, wondering if some grander structure might come from an assemblage of paper clips, pens, and binder clips? You’re not alone. Let your mind contemplate these beautiful maths sculptures from [Zachary Abel].

[Zachary] has a knack for both three-dimensional forms and the artistic use of color. His Möbius Clips sculpture ably takes 110 humble pieces of office equipment in multiple colors, and laces them into a continuous strip that has beguiled humanity for generations. The simple paper clip becomes a dodecahedron, a colorful spiralling ball, or a tightly-stitched box. He does great things with playing cards too.

What elevates his work is that there’s a mathematical structure to it. It’s so much more than a pile of stationary, there’s always a geometry, a pattern which your mind latches on to when you see it. He also often shares the mathematical background behind his work, too.

If you’re fumbling about with the contents of your desk drawer while another Zoom meeting drags on, you might want to challenge yourself to draw from [Zachary’s] example. If you pull off something fantastical, do let us know!

Digitally Reading A Micrometer’s Output

July 17, 2024 by Lewin Day 11 Comments

If you’re instrumenting your machine tools, or if you’re just curious, you might want to get granular access to the output of a digital micrometer or the like. [Tommy] set his mind to figuring out the communications protocol of the ClockWise Tools dial indicator for this very purpose. And he succeeded!

Work began by finding the clock and signal lines for the gauge. With those identified, and the signals up on an AD2 logic analyzer, it was determined that once every 40 milliseconds, the device sent a data burst of six nibbles separated by 1.58 milliseconds apiece. The device communicates the absolute position of the gauge, and the data can be readily decoded with the aid of an op-amp to help boost up the 1.5-volt logic to a more reasonable level for a modern commodity microcontroller like the Arduino Nano. From there, the information can be trucked over serial to a PC, or you can do just about anything else with it besides.

We’ve seen similar hacks performed on calipers before, too, making automated measurements a breeze. If you’re working on something that needs precise measurements down to the, well… micrometer… this project might be just the thing you’re looking for.

FLOSS Weekly Episode 792: Rust Coreutils

July 17, 2024 by Jonathan Bennett 9 Comments

This week Jonathan Bennett and Jeff Massie chat with Sylvestre Ledru about the Rust Coreutils! Why would we want to re-implement 50 year old utilities, what’s the benefit of doing them in Rust, and what do the maintainers of the regular coreutils project think about it?

Continue reading “FLOSS Weekly Episode 792: Rust Coreutils” →

Hacker Tactic: Single-PCB Panels

July 17, 2024 by Arya Voronova 35 Comments

Ordering a PCB? Two of them? Three? Five? For about eight years now, I’ve been regularly ordering large numbers of different PCBs, and, naturally, have developed a toolkit to make things smoother. One trick is PCB panelization, and you should really know about it.

You might’ve encountered PCB panels already. Perhaps, if you order PCBA at a fab, you will get your board returned in a whole new form-factor, with rails on the sides that you have to snap off before your PCB is usable. Those rails are used so that your PCBs are easier to handle during assembly, but that’s far from the only reason why you would make a panel.

If you need multiple pieces of a PCB, your fab may say that building 50 pcs is classified as “large batch” and that takes longer than 30 days, which delays your entire PCB order. I’ve been there, five years ago, running out of time right before Chinese New Year. The fix was simple – I made a 2×2 panel and ordered that in quantity of 10-15. Panelization might be a little more expensive, or maybe even cheaper, but, most importantly, it will be faster.

In a few hours’ time, I sat down, figured out that KiCad has built-in features for panelization, and ordered panels instead of separate PCBs. Thanks to that, I made the Chinese New Year deadline that year and could successfully restock my store, letting me earn a fair bit of money instead of keeping a popular product out-of-stock – ultimately, helping my family stay up on rent that month.

Panelization lets you hack around many PCB ordering and assembly limitations, and I’ve only gotten started – there’s way way more! For now, let’s sort out panelizing multiples of the same PCB. As long as your boards are using KiCad (or KiCad-converted from Eagle/EasyEDA/Altium/gerbers), there’s no better software than KiKit.

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Making Art With Maxwell’s Equations

July 17, 2024 by Lewin Day 5 Comments

When you think of art, you might think of portraiture, landscapes, or other kinds of paintings. But mathematics can feel artistic at times, too. We’ve all seen gorgeous Mandelbrot fractals, and less gorgeous Julia fractals, but that’s not all that’s out there. As [Prof. Halim Boutayeb] demonstrates, Maxwell’s equations can show us some real beauty, too.

The work involves running simulations of multiple electromagnetic sources moving, bouncing around, interacting, and so on. The art comes in the plotting of the fields, in warm colors or just outright rainbows. The professor does a great job of pairing some of these videos with pumping electronic music, which only adds to the fun.

Of course, the colors are pretty, but there’s a lot of valuable physics going on behind all this. Thankfully, there are all kinds of additional resources linked for those eager to learn about the Finite Difference Time Domain method and how it can be used for valid simulation tasks.

Throw this kind of stuff on a projector at your next rave and you will not be disappointed. Video after the break.

Continue reading “Making Art With Maxwell’s Equations” →