Author: Jenny List

3431 Articles

Rock Salt May Lead The Way To Better Batteries

October 5, 2023 by 58 Comments

The regular refrain here when it comes to announcements of new battery chemistries hailed as potentially miraculous is that if we had a pound, dollar, or Euro for each one we’ve heard, by now we’d be millionaires. But still they keep coming, and it’s inevitable that there will one or two that break through the practicality barrier and really do deliver on their promise. Which brings us tot he story which has come our way today, the suggestion that something as simple as rock salt could triple the energy density of a lithium-ion vehicle battery.

The research led from Lawrence Berkeley National Laboratory started around the use of cobalt in the battery cathode, an expensive and finite resource with the added concern of being in large part a conflict mineral from the Democratic Republic of Congo. Cobalt is used in  the cathodes because its oxide crystals form a stable layered structure into which the lithium ions can percolate. Alternative layered-structure metal oxides perform less well in retaining the lithium ions, making them unsuccessful substitutes. It seems that the three-dimensional structure of a rock salt crystal performs up to three times better than any layered oxide, which is where the excitement comes from.

Of course, if it were that simple we’d all be using three-times-more-powerful, half-price 18650s right now, which of course we aren’t. The challenge comes in making a rock salt cathode which both holds the lithium ions, and keeps that property reliably over the thousands of charge cycles needed for a real-world application. This one may yet be anther dollar on that metaphorical pile, but it just might give us the batteries we’ve been looking for.

Then again, when you’re looking at exciting battery chemistry, why limit yourself to lithium?

Using 5V Programmable Logic Here In The 2020s

October 4, 2023 by 29 Comments

Do you speak GAL? [Peterzieba] does, and has pulled together a collection of documents and tools so that you can too. There’s a dividing line in electronic engineering education, between those who were taught about FPGAs, and those who weren’t. Blurring that line slightly is gate array logic (GAL). These devices were a preceursor to the FPGA, with a much simpler structure, and usually in those days UV-erasable in the same manner as an EPROM. And oddly enough, they, or at least their successor compatible parts, are still available, and as handy DIP devices that talk to 5 volt logic.

The guide goes into detail about the parts, the terminology surrounding them, and the CUPL language which raises a few memories for us. There are several possible workflows, including for those not faint of heart, the possibility of writing a fusemap by hand. We’re impressed by that one.

If these devices interest you, our colleague Bil Herd wrote a two-part guide (part one, and part two) which should answer your questions.

Thanks [Bjonnh] for the tip!

Featured image: “Commodore Amiga 1000 – sub board – Texas Instruments PAL16L8ACN-0126” by Raimond Spekking

Review: LibrePCB Hits Version 1.0

October 3, 2023 by 53 Comments

Nearly three years ago at the start of 2020 and before the pandemic hit, we took a look at an up-and-coming player in the world of PCB design. LibrePCB is by no means as old as the more established players, but at the time it was joining the ranks of open-source EDA packages with its first early stable releases. It showed a lot of promise but was still a little rough around the edges back then, but in the years since it’s advanced to the extent that in September they released version 1.0. That’s a significant moment for any open source package, so it’s time to return and take another look. It’s a cross-platform package with builds available for Linux, Windows, MacOS and FreeBSD, of which I needed the Linux version. There are one or two options to choose from, I went for the appImage as probably the least trouble. Very quickly I was in a new EDA package, and I set out to make a simple Schmitt trigger oscillator as a test project. Continue reading “Review: LibrePCB Hits Version 1.0” →

At Last! Faster OpenSCAD Rendering Is On The Horizon

October 3, 2023 by 30 Comments

Known as “The Programmers Solid 3D CAD Modeller”, OpenSCAD is used by many people for whom writing code comes more naturally than learning a fiddly user interface. It’s a very capable piece of software, but regular users will tell you that it can be rather slow when it comes to rendering your work. We’re very pleased to see that a fix for this has been produced courtesy of [@ochafik], can now be found as an experimental feature in nightly builds, and will in due course no doubt find its way to official releases.

Despite a modern computer invariably having a multi-core architecture, it might surprise you to find that OpenSCAD wasn’t able to take advantage of this previously. The above-linked thread spans over a decade of experimenting and contains some fascinating discussions if you’re prepared to wade through it, and culminates a few weeks ago in the announcement of the new feature giving access to multiple CPUs. We don’t have it yet, but it’s great to know it’s in the works and we’re looking forward to render time involving considerably less of a wait.

So many OpenSCAD projects have passed through these pages over the years, it’s safe to say that it has a significant user base among Hackaday readers. It’s still something an AI hasn’t mastered yet though.

Thanks [pca006132] for the tip.

Hackaday Prize 2023: An Agricultural Robot That Looks Ready For The Field

October 2, 2023 by 12 Comments

In the world of agriculture, not all enterprises are large arable cropland affairs upon which tractors do their work traversing strip by strip under the hot sun. Many farms raise far more intensive crops on a much smaller scale, and across varying terrain. When it comes to automation these farms offer their own special challenges, but with the benefit of a smaller machine reducing some of the engineering tasks. There’s an entry in this year’s Hackaday prize which typifies this, [KP]’s Agrofelis robot is a small four-wheeled carrier platform designed to deliver autonomous help on smaller farms. It’s shown servicing a vineyard with probably one of the most bad-ass pictures you could think of as a pesticide duster on its implement platform makes it look for all the world like a futuristic weapon.

A sturdy tubular frame houses the battery bank and brains, while motive power is provided by four bicycle derived motorized wheels with disk brakes. Interestingly this machine steers mechanically rather than the skid-steering found in so many such platforms. On top is a two degrees of freedom rotating mount which serves as the implement system — akin to a 3-point linkage on a tractor. This is the basis of the bad-ass pesticide duster turret mentioned above. Running it all is a Nvidia Jetson Nano, with input from a range of sensors including global positioning and LIDAR.

The attention to detail in this agricultural robot is clearly very high, and we could see machines like it becoming indispensable in the coming decades. Many tasks on a small farm are time-consuming and involve carrying or wheeling a small machine around performing the same task over and over. Something like this could take that load off the farmer. We’ve been there, and sure would appreciate something to do the job.

While we’re on the subject of farm robots, this one’s not the only Prize entry this year.

The HackadayPrize 2023 is Sponsored by:

The Magic Of A Diode Sampler To Increase Oscilloscope Bandwidth

September 30, 2023 by 25 Comments

Making an oscilloscope is relatively easy, while making a very fast oscilloscope is hard. There’s a trick that converts a mundane instrument into a very fast one, it’s been around since the 1950s, and [CuriousMarc] has a video explaining it with an instrument from the 1960s. The diode sampler is the electronic equivalent of a stroboscope, capturing parts of multiple cycle of a waveform to give a much-slowed-down representation of it on the screen. How it works is both extremely simple, and also exceptionally clever as some genius-level high-speed tricks are used to push it to the limit. We’ve put the video below the break.

[Marc] has a Keysight 100 MHz ‘scope and the sampler allows him to use it to show 4 GHz. Inside the instrument is a pair of sample-and-hold circuits using fast diodes as RF switches, triggered by very low-rise-time short pulses. Clever tricks abound, such as using the diode pair to cancel out pulse leakage finding its way back to the source. To complete this black magic, an RF-tuned stub is utilized to help filter the pulses and further remove slower components.

It’s slightly amusing to note that the Keysight 100 MHz ‘scope is now “slow” while the early sampling ‘scopes had their “fast” capabilities in that range. The same technique is still used today, in fact, you probably have one on your bench.

The sampler he’s showing us is an accessory for another instrument we’ve previously shown you his work with.

Continue reading “The Magic Of A Diode Sampler To Increase Oscilloscope Bandwidth” →

CNC Soldering Bot Handles Your Headers

September 30, 2023 by 39 Comments

Soldering pin headers by hand is a tedious task, especially when your project has a huge number of them. [iforce2d] has a large number of boards with a lot of headers, and has created a rather special CNC machine to to do the job. It’s a soldering robot, controlled by LinuxCNC and you can see it below the break.

Superficially it resembles a 3D printer made in aluminium, with an X-Y movable table and a Z-direction represented by a soldering iron and solder feeder on an arm. The solder feeder uses a Bowden tube, with a 3D-printer extruder motor pushing the solder wire down a PTFE tube and finally into a fine aluminium tube from which it’s fed to the iron tip.

Though he’s done a beautiful job of it, creating the machine is not all that’s required, because the tool path requires more attention than simply moving the iron to each pin and supplying some solder. There’s a need to consider the effect of that heat, how much each pad needs, and how much neighbouring pads contribute.

We’ve had repetitive soldering tasks just like this one though not on this scale, so we can understand the tedium this machine will relieve. We can’t however help being reminded of XKCD 1319.

Continue reading “CNC Soldering Bot Handles Your Headers” →