Turn the clock back a couple of decades, and the only time the average person would have given much thought to batteries was when the power would go out, and they suddenly needed to juice up their flashlight or portable radio. But today, high-capacity batteries have become part and parcel to our increasingly digital lifestyle. In fact, there’s an excellent chance the device your reading this on is currently running on battery power, or at least, is capable of it.
So let’s get to know batteries better. What’s the chemical process that allows them to work? For that matter, what even is a battery in the first place?
It’s these questions, and more, that made up this week’s Battery Engineering Hack Chat with Dave Sopchak. Our last Hack Chat of 2022 ended up being one of the longest in recent memory, with the conversation starting over an hour before the scheduled kickoff and running another half hour beyond when emcee Dan Maloney officially made his closing remarks. Not bad for a topic that so often gets taken for granted.
When NASA’s Orion capsule splashed down in the Pacific Ocean yesterday afternoon, it marked the end of a journey that started decades ago. The origins of the Orion capsule can be tracked back to a Lockheed Martin proposal from the early 2000s, and development of the towering Space Launch System rocket that sent it on its historic trip around the Moon started back in 2011 — although few at the time could have imagined that’s what it would end up being used for. The intended mission for the incredibly powerful Shuttle-derived rocket changed so many times over the years that for a time it was referred to as the “Rocket to Nowhere”, as it appeared the agency couldn’t decide just where they wanted to send their flagship exploration vehicle.
But today, for perhaps the first time, the future of the SLS and Orion seem bright. The Artemis I mission wasn’t just a technical success by about pretty much every metric you’d care to use, it was also a public relations boon the likes of which NASA has rarely seen outside the dramatic landings of their Mars rovers. Tens of millions of people watched the unmanned mission blast off towards the Moon, a prelude to the global excitement that will surround the crewed follow-up flight currently scheduled for 2024.
As NASA’s commentators reminded viewers during the live streamed segments of the nearly 26-day long mission around the Moon, the test flight officially ushered in what the space agency is calling the Artemis Generation, a new era of lunar exploration that picks up where the Apollo left off. Rather than occasional hasty visits to its beautiful desolation, Artemis aims to lay the groundwork for a permanent human presence on our natural satellite.
With the successful conclusion of the Artemis I, NASA has now demonstrated effectively two-thirds of the hardware and techniques required to return humans to the surface of the Moon: SLS proved it has the power to send heavy payloads beyond low Earth orbit, and the long-duration flight Orion took around our nearest celestial neighbor ensured it’s more than up to the task of ferrying human explorers on a shorter and more direct route.
But of course, it would be unreasonable to expect the first flight of such a complex vehicle to go off without a hitch. While the primary mission goals were all accomplished, and the architecture generally met or exceeded pre-launch expectations, there’s still plenty of work to be done before NASA is ready for Artemis II.
Fair warning for readers with a weak stomach, the video below graphically depicts an innocent rubber band airplane being obliterated in mid-air by a smug high-tech RC helicopter. It’s a shocking display of airborne class warfare, but the story does have a happy ending, as [Concrete Dog] was able to repair his old school flyer with some very modern technology: a set of 3D printed propeller blades.
Now under normal circumstances, 3D printed propellers are a dicey prospect. To avoid being torn apart by the incredible rotational forces they will be subjected to, they generally need to be bulked up to the point that they become too heavy, and performance suffers. The stepped outer surface of the printed blade doesn’t help, either.
But in a lightweight aircraft powered by a rubber band, obviously things are a bit more relaxed. The thin blades [Concrete Dog] produced on his Prusa Mini appear to be just a layer or two thick, and were printed flat on the bed. He then attached them to the side of a jar using Kapton tape, and put them in the oven to anneal for about 10 minutes. This not only strengthened the printed blades, but put a permanent curve into them.
The results demonstrated at the end of the video are quite impressive. [Concrete Dog] says the new blades actually outperform the originals aluminum blades, so he’s has to trim the plane out again for the increased thrust. Hopefully the extra performance will help his spindly bird avoid future aerial altercations.
This week, Editor-in-Chief Elliot Williams and Managing Editor Tom Nardi start the Hackaday Podcast by talking about another podcast that’s talking about…Hackaday. Or more accurately, the recent Hackaday Supercon. After confirming the public’s adoration, conversation moves on to designing flexible PCBs with code, adding a rotary dial to your mechanical keyboard, and a simulator that lets you visualize an extinction-level event. We’ll wrap things up by playing the world’s smallest violin for mildly inconvenienced closed source software developers, and wonder how the world might have been different if the lady of the house had learned to read binary back in 1969.
Check out the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
At this point, you’re likely aware that you can store your wireless network’s credentials in a QR code, so that anyone who wants to connect with their smartphone need only scan the 2D barcode. Whether you print it out on paper, extrude it out of plastic, or paint the thing on the wall, it still works the same. It’s a neat trick for when you’ve got friends and family over, and saves you having to explain your ponderously long WPA key.
But what if you want to change up the encryption key every so often? Sure would be a hassle to have to repaint the wall. Enter this interesting project from [Predrag Mijatovic], which uses a few scripts to automatically set up a new encrypted guest WiFi network and present the appropriate QR code on an OLED display attached to a Raspberry Pi Pico. It’s a bit convoluted, and almost certainly won’t work on your network without significant tweaks, but we’re intrigued by the idea.
As [Predrag] explains, the whole thing is based on a Latvian MikroTik router that can be configured over SSH. A Bash script generates a new encryption key by base64 encoding the output /dev/urandom, logs into the router to set up a new network using it, and then generates the matching ASCII QR code. With some sed trickery, the code is then embedded into a MicroPython program that gets uploaded to the connected Pi Pico.
In the video after the break [Predrag] takes us through the process manually so it’s easier to see what’s going on. Under normal circumstances, it would all happen automatically and would take just a few seconds to complete. We’d feel more comfortable if the scripts had some error correction that would allow them to gracefully exit if something goes wrong, but as a proof of concept, it certainly works.
Over the last couple years, we’ve seen an absolute explosion of masked stereolithography (MSLA) 3D printers that use an LCD screen to selectively block UV light coming from a powerful LED array. Combined with a stepper motor that gradually lifts the build plate away from the screen, this arrangement can be used to produce high-resolution 3D prints out of photosensitive resins. The machines are cheap, relatively simple, and the end results can be phenomenal.
But they aren’t foolproof. As [Jan Mrázek] explains, these printers are only as good as their optical setup — if they don’t have a consistent UV light source, or the masking LCD isn’t working properly, the final printed part will suffer. In an effort to better understand how these factors impact print quality, he designed the DrLCD: a TSL2561 luminosity sensor mounted to a robotic arm with associated software to map out the printer’s light source.
The individual LED assemblies are clearly visible.
The results when running DrLCD against a few different types of printers is fascinating. [Jan] was clearly able to make out the type of lenses used, and in one case, was even able to detect that a darker spot in the scan was due to a bit of resin having leaked into the light source and clouded up the optics.
But DrLCD can do more than just tell you where you’ve got a dark spot. Using the data collected from the scan, it’s possible to create a “compensation map” that can be combined with the sliced model you wish to print. As the slicer assumes an idealistic light source, this map can help by adding additional masking where bright spots in the display have been detected.
[Jan] goes on to compare the dimensional accuracy of printed parts before and after the compensation map has been applied to the model, and was able to identify a small but distinctive improvement. Not everyone is going to be concerned about the 157 µm deviation observed without the backlight compensation, but we certainly aren’t going to complain about 3D printers getting even more dimensionally accurate.
A couple years back we covered a similar technique that used a DSLR to capture high-resolution images of the bed. While arguably much easier to pull off, we can’t help but fall in love with the glorious overengineering that went into the DrLCD system, and we can’t wait until it starts making house calls.
Regular Hackaday readers may recall the Inkplate family of devices: open source all-in-one development boards that combine the power and versatility of the ESP32 with electronic paper displays salvaged from commercial e-readers. By taking the sharp, high-speed, displays intended for readers such as Amazon’s Kindle and bundling it together with all the hardware and software you need to make it work, the Inkplate provided a turn-key platform for anyone looking to get serious with e-paper.
Given the fact that their screens were pulled from recycled readers, it’s no surprise the previous Inkplate entries came in familiar 6 and 10 inch variants. There was even an upgraded 6 inch model that benefited from newer reader technology by adopting a touch-sensitive backlit panel, which we took a close look at last year. Their large displays make them excellent for wall mounted applications, such as a household notification center or constantly-changing art display. Plus, as you might expect, the Inkplate is an ideal choice for anyone looking to roll their own custom e-reader.
But of course, not every application needs so much screen real estate. In fact, for some tasks, such a large display could be considered a liability. Seeing a void in their existing product lineup, the folks at Soldered Electronics (previously e-radionica) have recently unveiled the diminutive Inkplate 2. This new miniature Inkplate uses the same software library as its larger predecessors, but thanks to its 2.13 inch three-color display, lends itself to a wider array of potential projects. Plus it’s considerably cheaper than the larger Inkplate models, at just $35 USD.
Considering the crowd sourced funding campaign for the Inkplate 2 blew past its goal in just 72 hours, it seems clear there’s plenty of interest in this new smaller model. But if you’re still not sure if it’s the e-paper solution you’ve been waiting for, maybe we can help — the folks at Soldered sent along a pre-production version of the Inkplate 2 for us to play around with, so let’s take it for a test drive and see what all the fuss is about.
