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Hardware hacking how-tos

One Tool Twists Wires, And Skewers Shish Kebabs

February 11, 2022 by 19 Comments

Twisting stranded wire with your fingers in preparation for tinning and/or soldering is almost a reflex for folks making electronic assemblies. But what if the wires are too close to get your fingers around, or you have the fingers of a sumo wresters? Well [DIYDSP] has a solution for you (see video below the break) that’s easy to make from a shish kebab skewer that’s probably rolling around your kitchen drawer. The reason that [DIYDSP] wanted to twist such closely spaced wires was to solder a length of 0.1 in O.C. stranded ribbon cable directly onto a PCB pin header pattern.

The method is very simple. Drill a long hole in the factory-cut flat end, followed by using a countersink bit to give a conical taper to guide the wires in. [DIYDSP] found that a 1/16 inch (1.6 mm) drill bit was a bit too large to grip the types of wires he was using, and finally settled on a 0.6 mm bit. If you are using larger wires, you should experiment to get the right size, or just build a handful of these of differing diameters since they’re so easy to make — just mark them clearly so you don’t accidentally grill shish kebabs with them on the BBQ.

The resulting tool is not unlike the business end of a hand-held wire-wrap tool, but works different principle and is a fraction of the cost. If you do any amount of interconnect wiring with stranded wires, then you should check out this video and whip up a couple of these to throw in your tool box.

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A Guide To Milling PCBs At Home

February 9, 2022 by 31 Comments

If you keep up with various retro vacuum tube projects, you probably have run across [UsagiElectric] aka [David]’s various PCBs that he makes on his own Bridgeport EZ-Track 3-axis milling machine — massively oversized for the job, as he puts it. In a recent video, [David] walks us through the steps of making a sample PCB, introducing the various tools and procedures of his workflow. He points out that these are the tools he uses, but the overall process should be similar no matter what tools you use.

  • Logisim to validate logic designs
  • TINA-TI, Texas Instrument’s version of the TINA SPICE simulator
  • DesignSpark PCB for schematic entry and PCB layout
  • FlatCAM, a computer-aided PCB manufacturing tool

For this video, [David] makes a half-adder circuit out of four vacuum tubes plus a seven-segment VFD tube to show the combined sum and carry outputs. Momentary switches are used to generate the two addends. Using this example, he proceeds to design, simulate, build and demonstrate a working circuit board. We like his use of the machined pin socket inserts for building a vacuum tube socket directly into the board.

Now this process isn’t for everyone. First of all, a Bridgeport mill is a pretty good sized, and heavy, tool. That said, these procedures should adapt well to other milling machines and engravers. We should point out that [David] is making boards mostly for vacuum tubes, where circuit trace width and spacing distances are generous. If you’re planning to make home PCBs for a 273-pin PGA chip, this isn’t the technique for you.

It seems that the bulk of [David]’s vacuum tube PCBs are single-sided, and reasonably so. They use wire links here and there to jump over traces. Adapting this process to double-sided PCBs is doable, but more complex. Are you milling double-sided boards in your lab? If so, let us know about it in the comments below.

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A graph visualising approximation errors - the specific principle pictured is described well by the linked article

Time And Accuracy In Las ATMegas

January 31, 2022 by 4 Comments

Do you ever have to ensure that an exact amount of time passes between two tasks in your microcontroller code? Do you know what’s the difference between precision and accuracy? Today, [Jim Mack] tells us about pushing timers and interrupts to their limits when it comes to managing time, while keeping it applicable to an ever-popular ATMega328P target! Every now and then, someone decides to push the frontiers of what’s possible on a given platform, and today’s rules is coding within constraints of an Arduino environment. However, you should check [Jim]’s post out even if you use Arduino as a swearword – purely for all of the theoretical insights laid out, accompanied by hardware-accurate examples!

This will be useful to any hacker looking to implement, say, motor encoder readings, signal frequency calculations, or build a gadget processing or modifying audio in real time. To give you a sample of this article, [Jim] starts by introducing us to distinctions between precision and accuracy, and then presents us with a seemingly simple task – creating exactly 2400 interrupts a second. As much as it might look straightforward, problems quickly arise when clock crystal frequency doesn’t cleanly divide by the sampling frequency that you have to pick for your application! This is just a taste of all the examples of hidden complexity presented, and they’re accompanied with solutions you can use when you eventually encounter one of these examples in your hacker pursuits. In the end, [Jim] concludes with links to other sources you can study if you ever need to dig deeper into this topic.

Keeping our projects true to the passage of time can be an issue, and we’ve been at it for ages – calibrating your RC oscillator is a rite of passage for any ATTiny project. If you ever decide to have an interrupt peripheral help you with timing issues, we’ve gone in-depth on that topic in the past, with a three-part series describing the benefits, the drawbacks and the edgecases of interrupts. Going for a more modern target? Our piece on using interrupts with STM32 is a great path for trying out tools of the modern age.

View of a well-organized workspace in front of a window view to outdoors

How To Optimize Your Workspace: Analyze How You Work

January 24, 2022 by 27 Comments

[Jay Carlson] has shared some fantastic guidance on how to optimize one’s home workspace, and you just might want to emulate some of his layout, especially if you routinely juggle multiple projects. He makes the important point that different people have different needs, so one size does not fit all. Optimizing one’s workspace must first take into account what kind(s) of work one does, and many of his tips and tricks are pretty broadly applicable.

A rack of trays, each with a project
Looking online for these? A common industry term is “bun rack”. This one is “half-height” in size.

[Jay] works on embedded systems, and often switches between many different jobs and projects. Get your notepads ready, because there are plenty of great takeaways.

For example, to get a good top-down camera view of what’s on the workbench, he uses a camera mounted on an articulated arm (the kind that usually has a lamp attached to the end.) This makes the camera easy to deploy and easy to stow, and he can effortlessly save footage or share video with colleagues online.

Another great tip is using what most of us would call cafeteria trays and a matching rack. With each tray devoted to a different project or version of hardware, it makes switching between jobs as simple as sliding in one tray and pulling out another. It’s also a highly space-efficient way to store a lot of in-progress hardware. [Jay] gives a detailed walkthrough of his workspace and explains every decision, it’s well worth a read.

It’s always better to save space, as long as doing so doesn’t negatively impact the work itself. If you’re looking for space-saving tips, be sure to check out this tiny workshop’s space-saving hacks for more ideas.

Cables Too Long? Try Cable Management Via DIY Coiling

January 23, 2022 by 34 Comments

Annoyed by excessively-long cables? Tired of the dull drudgery and ugly results of bunching up the slack and wrapping it with a twist-tie? Suffer no longer, because the solution is to make your own coiled cables!

[Dmitry] is annoyed with long, unruly cables and shared a solution he learned from the DIY keyboards community: coil them yourself with a piece of dowel, a hair dryer, and about 10 minutes of your time. However, it’s just a wee bit more complicated than it may seem at first glance.

The process begins with wrapping a cable around a mandrel, then heating it as uniformly as possible to thermoform the jacket, but the instructional video (embedded below) says that all by itself that isn’t quite enough to yield lasting results. After heating the cable and letting it cool, the coils will be formed but it will not hold the new shape very well. The finishing touch is to “reverse” the direction of the coils, by re-wrapping it backward around the mandrel, inverting the coils upon themselves. This process is awkward to explain, but much simpler to demonstrate. This video by [DailySetupTech] explains this process around the 2:30 mark. That final step is what yields a tightly-wound, springy coil.

The nice part about using this process as a cable management technique is that it is possible to coil only a portion of a cable, leaving the exact amount of uncoiled slack required for a given application. Keep it in mind the next time some cables need managing. And if you don’t want to coil a cable but still need it out of the way, you might find this design for a DIY cable chain made from a tape measure useful.

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Advanced PCB Graphics With KiCAD 6 And Inkscape

January 8, 2022 by 16 Comments

There are many, many video tutorials about designing the functional side of PCBs, giving you tips on schematic construction, and layout tips. What is a little harder to find are tutorials on the graphical aspects, covering the process from creating artworks and how you can drive the tools to get them looking good on a PCB, leveraging the silkscreen, solder and copper layers to maximum effect. [Stuart Patterson] presents his guide for Advanced PCB Graphics in KiCAD 6.0 and Inkscape, (Video, embedded below) to help you on your way to that cool looking PCB build.

Silkscreen layers in yellow, solder mask opening in red

The first step is to get your bitmap, whether you create it yourself, or download it, and trace it into a set of vectors using the Inkscape ‘trace bitmap’ tool. If you started with an SVG or similar vector shape, then you can skip that stage.

Next simply create a PCB outline shape by deleting all the details that aren’t part of the outline. A little scaling here and there to get the dimensions correct and you’re done with the first part. [Stuart] has an earlier video showing that process.

The usability improvements in KiCAD 6.0 are many, but one greatly demanded feature is the ability to group objects, just like you do in Inkscape and any other vector graphics tool for that matter. That means you can simply import that SVG outline into the Edge.Cuts PCB layer and all the curves will be nicely tied together. Next you select the details you want for the silkscreen layer, solder mask removal layers and any non-circuit copper. In Inkscape it would be wise to use the layers feature to assign the different material types to a uniquely named layer, so they can be hidden for exporting. This allows you to handle silk, mask and copper PNG exports from a single master file, in addition to any vector details for outline, slots and holes.

Once you have PNG bitmap exports for the silk, mask etc. you need to create a footprint inside a board-specific library, using the KiCAD image converter tool. It was interesting to note that you can export a new image footprint from the tool and paste it straight into the footprint editor, and tweak all the visibility details at the same time. That will save some time and effort for sure. Anyway, we hope this little tutorial from [Stuart] helps, and we will be sure to bring you plenty more in the coming months.

Need some more help with KiCAD? Checkout this tutorial, and if you want a bit more power from the tool, you need some action plugins!

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Jet burner and close-up

$7 Tent Heater Provides Comfort On A Budget

January 6, 2022 by 120 Comments

At Hackaday’s Minnesota office, we appreciate central heat and hot coffee because the outdoor temperature is sub-zero in Celsius and Fahrenheit. Not everyone here has such amenities, and families living in tents could use heater help. If you live somewhere inhospitably cold and have the resources (time being the most crucial), please consider building and donating alcohol jet burners.

Alcohol burners like these are great for tents because if they tip over, they self-extinguish. You can fill them with 70% rubbing alcohol and they’ll heat a small space, and if running on denatured alcohol, they can be used to cook with. They won’t do you much good outdoors unless you have significant wind protection, as the tiny jet is likely to blow out. The first time you light one, you must heat the coil with a lighter or another heater to vaporize incoming fuel, then it can sustain itself by wicking fluid up from the reservoir jar. Relighting after a tip or accidental gust only takes a spark since the copper is already hot.

If you came for a hack, note how they fill the small tubes with salt funneled through a condiment cap before bending them. Sure, there are springy pipe bending tools, but who doesn’t already have salt and tape? Keeping humans warm is crucial, but heating metal takes a different approach.

Thank you for the tip, [cyberlass]