Hacker Tactic: Building Blocks

October 24, 2024 by Arya Voronova 11 Comments

The software and hardware worlds have overlaps, and it’s worth looking over the fence to see if there’s anything you missed. You might’ve already noticed that we hackers use PCB modules and devboards in the same way that programmers might use libraries and frameworks. You’ll find way more parallels if you think about it.

Building blocks are about belonging to a community, being able to draw from it. Sometimes it’s a community of one, but you might just find that building blocks help you reach other people easily, touching upon common elements between projects that both you and some other hacker might be planning out. With every building block, you make your or someone else’s next project quicker, and maybe you make it possible.

Sometimes, however, building blocks are about being lazy.

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Supercon 2023: Aleksa Bjelogrlic Dives Into Circuits That Measure Circuits

September 11, 2024 by Lewin Day 10 Comments

Oscilloscopes are one of our favorite tools for electronics development. They make the hidden dances of electrons visually obvious to us, and give us a clear understanding of what’s actually going on in a circuit.

The question few of us ever ask is, how do they work? Most specifically—how do you design a circuit that’s intended to measure another circuit? Aleksa Bjelogrlic has pondered that very idea, and came down to explain it all to us at the 2023 Hackaday Supercon.

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Mobile Coffee Table Uses Legs To Get Around

September 10, 2024 by Bryan Cockfield 22 Comments

For getting around on most surfaces, it’s hard to beat the utility of the wheel. Versatile, inexpensive, and able to be made from a wide array of materials has led to this being a cornerstone technology for the past ten thousand years or so. But with that much history it can seem a little bit played out. To change up the locomotion game, you might want to consider using robotic legs instead. That’s what [Giliam] designed into this mobile coffee table which uses custom linkages to move its legs and get itself from place to place around the living room.

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Better Battery Design Through Science

August 2, 2024 by Bryan Cockfield 6 Comments

Before the age of lithium batteries, any project needing to carry its own power had to rely on batteries that were much less energy-dense and affordable. In many ways, we take modern lithium technology for granted, and can easily put massive batteries in our projects by the standards of just a few decades ago. While the affordability of lithium batteries has certainly decreased the amount of energy we need to put in to our projects to properly size batteries, there’s still a lot of work to be done if you’re working on a bigger project or just want to get the maximize the efficiency and effectiveness of your DIY battery pack.

The main problem with choosing a battery, as [ionworks] explains, is that batteries can’t be built for both high energy and high power, at least not without making major concessions for weight or cost. After diving in to all of the possible ways of customizing a battery, the battery guide jumps in to using PyBaMM to perform computational modeling of potential battery designs to hopefully avoid the cumbersome task of testing all of the possible ways of building a battery. With this tool virtually all of a battery’s characteristics can be simulated and potential problems with your setup can be uncovered before you chose (or start production of) a specific battery system.

While customizing a battery pack to this extent might not be a consideration for most of us unless the project is going to be big enough to run something like an electric car or a whole-house generator, it’s a worthwhile tool to know about as even smaller projects like ebikes can benefit from choosing the right cell for the application. Some of the nuances of battery pack design can be found in this guide to building packs from the standard 18650 cells.

Header: Lead holder, CC BY-SA 3.0 .

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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A FreeCAD sticker, a FreeCAD pencil, a Hackaday Jolly Wrencher SAO PCB and the board-to-be-encased next to each other

FreeCAD Foray: Shells For All Our PCBs

July 1, 2024 by Arya Voronova 58 Comments

Are you the kind of hacker who tries to pick up FreeCAD, but doesn’t want to go through a tutorial and instead pokes around the interface, trying to transfer the skills from a CAD suite you’ve been using before? I’ve been there too, and in my experience, FreeCAD doesn’t treat such forays lightly. It’s a huge package that enables everything from architecture to robotics design, so if you just want a 3D-printed case for a PCB project, the hill can be steep. So let’s take that first simple project as an example, and see if it helps you learn a little bit of FreeCAD.

As motivation, I recently built a USB-C PSU board that uses a DC PSU and does the USB-C handshaking to provide 20 V to a laptop. It is currently my only 100 W USB-C PSU, and my 60 W PSU just died, which is why I now use this board 24/7. I have brought it on two different conferences so far, which has highlighted a problem – it’s a board with tons of exposed contacts, which means that it isn’t perfectly travel-friendly, and neither it is airport-friendly – not that I won’t try and bring it anyway. So, currently, I have to watch that nothing shorts out – given the board has 3.3 V close to 20 V at 9 A, it’s a bit of a worry.

This means I have to design some sort of case for it. I was taught SolidWorks in the half a year that I spent in a university, and honestly, I’m tired of the licensing and proprietary format stuff. When it comes to more hobbyist-accepted tools like Fusion360, I just don’t feel like exchanging one proprietary software for another. So, FreeCAD is the obvious choice – apart from OpenSCAD, which I know and love, but I don’t always want to think up fifteen variable names for every silly little feature. That, and I also want to fillet corners every now and then.

For a full-open-source workflow, today’s PCB is designed with KiCad, too. Let’s see about installing FreeCAD, and the few things you need to import a KiCad board file into FreeCAD.

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CADmium Moves CAD To The Browser

May 23, 2024 by Bryan Cockfield 43 Comments

For plenty of computer users, the operating system of choice is largely a middleman on the way to the browser, which hosts the tools that are most important. There are even entire operating systems with little more than browser support, under the assumption that everything will be done in the browser eventually. We may be one step closer to that type of utopia as well with this software tool called CADmium which runs exclusively in a browser.

As the name implies, this is a computer-aided design (CAD) package which looks to build everything one would need for designing project models in a traditional CAD program like AutoCAD or FreeCAD, but without the burden of needing to carry local files around on a specific computer. [Matt], one of the creators of this ambitious project, lays out the basic structure of a CAD program from the constraint solver, boundary representation (in this case, a modern one built in Rust), the history tracker, and various other underpinnings of a program like this. The group hopes to standardize around JSON files as well, making it easy to make changes to designs on the fly in whatever browser the user happens to have on hand.

While this project is extremely early in the design stage, it looks like they have a fairly solid framework going to get this developed. That said, they are looking for some more help getting it off the ground. If you’ve ever wanted something like this in the browser, or maybe if you’ve ever contributed to the FreeCAD project and have some experience, this might be worth taking a look at.