How To Lace Cables Like It’s 1962

May 20, 2024 by Donald Papp 33 Comments

Cable harnesses made wire management a much more reliable and consistent affair in electronic equipment, and while things like printed circuit boards have done away with many wires, cable harnessing still has its place today. Here is a short how-to on how to lace cables from a 1962 document, thoughtfully made available on the web by [Gary Allsebrook] and [Jeff Dairiki].

It’s a short resource that is to the point in all the ways we love to see. The diagrams are very clear and the descriptions are concise, and everything is done for a reason. The knots are self-locking, ensuring that things stay put without being overly tight or constrictive.

According to the document, the ideal material for lacing cables is a ribbon-like nylon cord (which reduces the possibility of biting into wire insulation compared to a cord with a round profile) but the knots and techniques apply to whatever material one may wish to use.

Cable lacing can be done ad-hoc, but back in the day cable assemblies were made separately and electrically tested on jigs prior to installation. In a way, such assemblies served a similar purpose to traces on a circuit board today.

Neatly wrapping cables really has its place, and while doing so by hand can be satisfying, we’ve also seen custom-made tools for neatly wrapping cables with PTFE tape.

Lost Foam Casting In Action

May 19, 2024 by Jenny List 19 Comments

Even though not all of us will do it, many of us are interested in the art of casting metal. It remains a process that’s not out of reach, though, especially for metals such as aluminium whose melting points are reachable with a gas flame. The video below the break takes us through the aluminium casting process by showing us the lost-foam casting of a cylinder head for a BSA Bantam motorcycle.

The foam pattern is CNC milled to shape, and the leftover foam swarf is removed with a hot wire. The pattern is coated with a refractory coating of gypsum slurry, and the whole is set up in a tub packed with sand. We get the impression that the escaping gasses make this a tricky pour without an extra sprue, and indeed, they rate it as not perfect. The cooling fins on the final head are a little ragged, so it won’t be the part that goes on a bike, but we can see with a bit of refining, this process could deliver very good results.

For this pour, they use a gas furnace, but we’ve seen it done with a microwave oven. Usually, you are losing wax, not foam, but the idea is the same.

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DisplayPort: Hacking And Examples

May 16, 2024 by Arya Voronova 16 Comments

So far, I’ve talked about why DisplayPort is the future, introduced the basics of how to work with it on the hacker level, took apart and tamed the DisplayPort altmode, and recently, went through the eDP (embedded DisplayPort) display technology. This time, I want to give you a project library to reference, so that your hacking goes as smoothly as possible – real-world examples of open-source DisplayPort boards, a few boards I’ve worked on, part numbers, and whatever other information you might need.

Even this wonderful build is not immune from wasting power on unnecessary video conversion

Over the past few years, I’ve noticed that a non-zero amount of cyberdeck builders buy eDP screens with HDMI converter boards on Aliexpress, then connect them to SBCs using USB-C to HDMI adapters, or ignore the onboard eDP port; even this super cool Framework-based cyberdeck has done that! I get that it’s the simplest option, but I do believe that you ought to know how to improve it. The issue is that this double-conversion decreases the battery life significantly by burning two extra ASICs doing video conversion back and forth. Every hour of battery life matters in a cyberdeck, doubly so if it’s based on a low-power device already – you could easily cut your battery life in half if you’re not careful!

With these projects and references in your arsenal, my aim is that DisplayPort becomes way more comfortable for you to work with. Thankfully, there are quite a few projects to reference by now – let’s delve in.

Right out of the gate – are you looking for an SBC with DisplayPort support? The BoardDB website, a database of single-board computers, has a DisplayPort filter – click this link with the filter already enabled and browse through.

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Think Again: Tips On Finding And Flexing Your Creativity

May 15, 2024 by Donald Papp 19 Comments

Technical work — including problem-solving — is creative work. In addition, creativity is more than a vague and nebulous attribute that either is or isn’t present when it’s needed. A short article by [Anthony D. Fredericks] gives some practical and useful tips on energizing and exercising one’s creativity.

Why would creative thinking be meaningful to a technical person? The author shares an anonymous observation that as children we’re taught to stay inside the lines, while as adults we are often expected to think outside the box. Certainly when it comes to technical tasks, our focus is more on logical thinking. But problem solving benefits as much from creative thinking as it does from more logical approaches.

How can one cultivate creative thinking? The main idea is that creativity is best flexed and exercised by actively looking for connections and similarities between highly dissimilar elements, rather than focusing on their differences. Some thought exercises are provided to help with this process. Like with any exercise, the more one does it, the better one becomes.

Practicing more creative thinking can help jolt new ideas and approaches to a tough problem, so give it a shot. It’s also worth keeping in mind that we all need a feeling of progress, especially during extended times of applying effort to something, so do yourself a favor and give yourself an occasional win.

Supercon 2023: Building The Ultimate Apple IIe, Decades Later

May 14, 2024 by Lewin Day 2 Comments

The Apple II was launched in 1977, a full 47 years ago. The Apple IIe came out six years later, with a higher level of integration and a raft of new useful features. Apple eventually ended production of the whole Apple II line in 1993, but that wasn’t the end. People like [James Lewis] are still riffing on the platform to this day. Even better, he came to Supercon 2023 to tell us all about his efforts!

[James]’s talk covers the construction of the Mega IIe, a portable machine of his own design. As the name suggests, the project was based on the Mega II chip, an ASIC for which he had little documentation. He wasn’t about to let a little detail like that stop him, though.

The journey of building the Mega IIe wasn’t supposed to be long or arduous; the initial plan was to “just wire this chip up” as [James] puts it. Things are rarely so simple, but he persevered nonetheless—and learned all about the Apple II architecture along the way.

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Displays We Love Hacking: LVDS And EDP

May 8, 2024 by Arya Voronova 20 Comments

There are times when tiny displays no longer cut it. Whether you want to build a tablet or reuse some laptop displays, you will eventually deal with LVDS and eDP displays. To be more exact, these are displays that want you to use either LVDS or eDP signaling to send a picture.

Of the two, LVDS is the older standard for connecting displays, and eDP is the newer one. In fact, eDP has mostly replaced LVDS for things like laptop and tablet displays. Nevertheless, you will still encounter both of these in the wild, so let’s start with LVDS.

The name “LVDS” actually comes from the LVDS signaling standard (Low-Voltage Differential Signaling), which is a fairly generic data transfer standard over differential pairs, just like RS485. Using LVDS signaling for embedded display purposes is covered by a separate standard called FPD-Link, and when people say “LVDS”, what they’re actually talking about is FPD-Link. In this article, I will also use LVDS while actually talking about FPD-Link. Barely anyone uses FPD-Link except some datasheets, and I’ll use “LVDS” because that’s what people actually use. It’s just that you deserve to know the distinction so that you’re not confused when someone mentions LVDS when talking about, say, industrial machinery.

Both LVDS and eDP run at pretty high frequencies – they’re commonly used for color displays with pretty large resolutions, so speed can no longer be a constraint. eDP, as a successor technology, is a fair bit more capable, but LVDS doesn’t pull punches either – if you want to make a 1024 x 768 color LCD panel work, you will use LVDS, sometimes parallel RGB – at this point, SPI just won’t cut it. There’s a lot of overlap – and that’s because LVDS is basically parallel RGB, but serialized and put onto diffpairs. Let me show you how that happened, and why it’s cool.

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Supercon 2023: MakeItHackin Automates The Tindie Workflow

May 7, 2024 by Arya Voronova 2 Comments

Selling your hardware hacks is a great way to multiply your project’s impact, get your creations into others’ hands, and contribute to your hacking-related budget while at it. If you’re good at it, your store begins to grow. From receiving a couple orders a year, to getting one almost every day – if you don’t optimize the process of mailing orders out, it might just start taking a toll on you.

That is not to say that you should worry – it’s merely a matter of optimization, and, now you have a veritable resource to refer to. At Supercon 2023, [MakeItHackin]/[Andrew] has graced us with his extensive experience scaling up your sales and making your shipping process as seamless as it could be. His experience is multifaceted, and he’s working with entire four platforms – Tindie, Lectronz, Etsy and Shopify, which makes his talk all that more valuable.

[MakeItHackin] tells us how he started out selling hardware, how his stores grew, and what pushed him to automate the shipping process to a formidable extent. Not just that – he’s developed a codebase for making the shipping experience as smooth as possible, and he’s sharing it all with us.

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