A Guide To CubeSat Mission And Bus Design

April 28, 2026 by Al Williams 8 Comments

If you mention the word bus, you might think of public transportation or, more likely for us, a way to connect things together. But in the satellite world, the bus is the part of a vehicle that supports the payload but isn’t itself the payload. Typically, that means the electric power system, propulsion, radios, and thermal control, among other systems. If you are designing a CubeSat, you will want to read A Guide to CubeSat Mission and Bus Design by [Frances Zhu].

The Creative Commons-licensed book has twelve chapters, ranging from systems engineering — that is, defining what you want to do — to analyzing structures, handling power, setting up communications, and more. Of particular interest to us was the chapter on command and data handling. The final chapters cover software, system integration, and there’s even a chapter on Ethics.

If you want to build a CubeSat or just want to learn more about how satellites actually work, this is a great read. There are videos and other features, too. If you don’t like reading in your browser, you can download an EPUB, PDF, or MOBI near the top of the page.

There are many resources for the want-to-be CubeSat builder. You can even start with an open source design.

Hackaday Links: April 19, 2026

April 19, 2026 by Tom Nardi 5 Comments

We’ll start things off this week with a story that’s developing more than 25 billion kilometers from Earth — on Friday, NASA announced that the command had been sent to shut down Voyager 1’s Low-energy Charged Particles (LECP) instrument. As the power produced by the spacecraft’s aging radioisotope thermoelectric generator (RTG) continues to dwindle, engineers at the Jet Propulsion Laboratory have been systematically turning off various systems to extend the mission for as long as possible. It’s believed that deactivating LECP should buy them another year, during which engineers hope to implement a more ambitious power-saving routine. If this sounds a bit familiar, you’re probably thinking of Voyager 2. The plug was pulled on its LECP instrument back in March of 2025.

The JPL engineers hope that their new plan may allow them to reactivate previously disabled systems on the twin space probes, but even if everything goes according to plan, there’s no fighting the inevitable. At some point, there simply won’t be enough juice in the RTGs to keep the lights on. Although it’s going to be a sad day when we have to bring you that news, surviving a half-century in space is one hell of a run.

Speaking of ending a run, just a week after Amazon announced that pre-2012 Kindles would no longer be supported, the company is letting users know that the Kindle software for PCs will be discontinued in June. In its current form, at least. As Good e-Reader reports, Amazon is developing a new client for users who want to access the Kindle ecosystem from their computers, but it will only run on Windows 11. Since older software could be used to strip DRM from purchased ebooks, it seems likely this is another attempt to lock the platform down.

Continue reading “Hackaday Links: April 19, 2026” →

No Plans For The Weekend? Learn Raytracing!

September 6, 2025 by Tyler August 15 Comments

Weekends can be busy for a lot of us, but sometimes you have one gloriously free and full of possibilities. If that’s you, you might consider taking a gander at [Peter Shirley]’s e-book “Learning Raytracing in One Weekend”.

This gradient is the first image that the book talks you through producing. It ends with the spheres.

This is very much a zero-to-hero kind of class: it starts out defining the PPM image format, which is easy to create and manipulate using nearly any language. The book uses C++, but as [Peter] points out in the introduction, you don’t have to follow along in that language; there won’t be anything unique to C++ you couldn’t implement in your language of choice.

There are many types of ray tracers. Technically, what you should end up with after the weekend ends is a path tracer. You won’t be replacing the Blender Cycles renderer with your weekend’s work, but you get some nice images and a place to build from. [Peter] manages to cram a lot of topics into a weekend, including diffuse materials, metals, dialectrics, diffraction, and camera classes with simple lens effects.

If you find yourself with slightly more time, [Peter] has you covered. He’s also released books on “Raytracing: The Next Week.” If you have a lot more time, then check out his third book, “Raytracing: The Rest of Your Life.”

This weekend e-book shows that ray-tracing doesn’t have to be the darkest of occult sciences; it doesn’t need oodles of hardware, either. Even an Arduino can do it..

Solar-Powered E-Reader With No Buttons

March 10, 2025 by Bryan Cockfield 21 Comments

Modern e-readers such as the Amazon Kindle are incredible pieces of engineering, but that doesn’t mean there’s no room for improvement. A device custom-built to your own specifications is always going to provide a more satisfying experience than something purchased off the shelf. That’s why [fel88] put together this custom e-reader which offers a number of unique features, such as a solar panel on the back and button-free operation.

One issue with modern e-readers, at least as [fel88] sees it, is that they have a lot of unnecessary features. This project removes most of them, stripping down the device to its core functionality: a straightforward menu for selecting books and gesture-sensing for navigating the menu as well as changing the pages. The only physical input on the device is a small reed switch to turn the device on. A 3D printed case holds the e-ink display and encloses the inner workings, driven by an Arduino Mega 2560 and powered by three lithium-ion capacitors (LICs) and a small solar panel.

By dropping all of the unnecessary features, the device doesn’t need to waste energy with things like WiFi or Bluetooth and can get around 880 pages on a single charge, not counting any extra energy coming in through the solar panel while it’s operating. The LICs will also theoretically improve its life cycle as well. If you’re still stuck with a paperweight when you formerly had a working e-reader, though, there are plenty of ways to bring old devices back to life as well.

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.

Obsolete E-Reader Gets New Life

November 13, 2023 by Bryan Cockfield 6 Comments

For those who read often, e-readers are a great niche device that can help prevent eye fatigue with their e-ink displays especially when compared to a backlit display like a tablet or smartphone, all while taking up minimal space unlike a stack of real books. But for all their perks, there are still plenty of reasons to maintain a library of bound paper volumes. For those who have turned back to books or whose e-readers aren’t getting the attention they once did, there are plenty of things to do with them like this e-book picture frame.

The device started life as a PocketBook Basic Touch, or PocketBook 624, a fairly basic e-reader from 2014, but at its core is a decent ARM chip that can do many more things than display text. It also shipped running a version of Linux, which made it fairly easy to get a shell and start probing around. Unlike modern smart phones this e-reader seems to be fairly open and able to run some custom software, and as a result there are already some C++ programs available for these devices. Armed with some example programs, [Peter] was able to write a piece of custom software that displays images from an on-board directory and mounted the new picture display using an old book.

There were a number of options for this specific device that [Peter] explored that didn’t pan out well, like downloading images from the internet to display instead of images on the device, but in the end he went with a simpler setup to avoid feature creep and get his project up and running for “#inktober”, a fediverse-oriented drawing challenge that happened last month. While not strictly in line with a daily piece of hand-drawn artwork, the project still follows the spirit of the event. And, for those with more locked-down e-readers there’s some hope of unlocking the full functionality of older models with this FOSS operating system.

2600 Breaks Free From DRM With PDF/EPUB Subscription

July 21, 2023 by Tom Nardi 13 Comments

Hackaday has been online in some form or another since 2004, which for the Internet, makes us pretty damn old. But while that makes us one of the oldest surviving web resources for hacker types, we’ve got nothing on 2600 — they’ve been publishing their quarterly zine since 1984.

While the physical magazine can still be found on store shelves, the iconic publication expanded into digital distribution some time ago, thanks largely to the Kindle’s Newsstand service. Unfortunately, that meant Amazon’s recent decision to shutter Newsstand threatened to deprive 2600 of a sizable chunk of their income. So what would any group of hackers do? They took matters into their own hands and spun-up their own digital distribution system.

As of today you’re able to subscribe to the digital version of 2600 in DRM-free PDF or EPUB formats, directly from the magazine’s official website. Which one you pick largely depends on how you want to read it: those looking for the highest fidelity experience should go with PDF, as it features an identical layout to the physical magazine, while those who are more concerned with how the content looks on their reader of choice would perhaps be better served by the flexibility of EPUB. After signing up you can download the current Summer issue immediately, with future issues hitting your inbox automatically. Load it onto your home-built Open Book, and you can really stick it to the establishment.

While the ending of this story seems to be a happy one, we can’t help but see it as a cautionary tale. How many other magazines would have the means and experience to offer up their own digital subscriptions? Or for that matter, how many could boast readers savvy enough to utilize it? The reality is many publications will be injured by Amazon’s decision, some mortally so. That’s a lot of power to be put into the hands of just one company, no matter how quick the shipping is.