Custom Touchpad PCBs Without The Pain

March 6, 2025 by Jenny List 9 Comments

Many of us use touch pads daily on our laptops, but rarely do we give much thought about what they really do. In fact they are a PCB matrix of conductive pads, with a controller chip addressing it and sensing the area of contact. Such a complex and repetitive pattern can be annoying to create by hand in an EDA package, so [Timonsku] has written a script to take away the work.

It starts with an OpenSCAD script (originally written by Texas Instruments, and released as open source) that creates a diamond grid, which can be edited to the required dimensions and resolution. This is then exported as a DXF file, and the magic begins in a Python script. After adjustment of variables to suit, it finishes with an Eagle-compatible board file which should be importable into other EDA packages.

We’ve never made a touchpad ourselves, but having dome other such repetitive PCB tasks we feel the pain of anyone who has. Looking at this project we’re struck by the thought that its approach could be adapted for other uses, so it’s one to file away for later.

This isn’t the first home-made touchpad project we’ve brought you.

Why 56k Modems Relied On Digital Phone Lines You Didn’t Know We Had

March 6, 2025 by Lewin Day 46 Comments

If you came of age in the 1990s, you’ll remember the unmistakable auditory handshake of an analog modem negotiating its connection via the plain old telephone system. That cacophony of screeches and hisses was the result of careful engineering. They allowed digital data to travel down phone lines that were only ever built to carry audio—and pretty crummy audio, at that.

Speeds crept up over the years, eventually reaching 33.6 kbps—thought to be the practical limit for audio modems running over the telephone network. Yet, hindsight tells us that 56k modems eventually became the norm! It was all thanks to some lateral thinking which made the most of the what the 1990s phone network had to offer.

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Illustrated Kristina with an IBM Model M keyboard floating between her hands.

Keebin’ With Kristina: The One With The Schreibmaschine

March 4, 2025 by Kristina Panos 5 Comments

Choc switches on a ThumbsUp! v8 keyboard with IBM Selectric typewriter keycaps, thanks to some 3D-printed adapters. — Image by [Sasha K.] via reddit

Remember that lovely Hacktric centerfold from a couple Keebins ago with the Selectric keycaps? Yeah you do. Well, so does [Sasha K.], who saw the original reddit post and got inspired. [Sasha K.] has more than one IBM Selectric lying around, which is a nice problem to have, and decided to strip one of its keycaps and get to experimenting.

The result is a nice adapter that allows them to be used with Kailh chocs — you can find the file on Thingiverse, and check out the video after the break to see how they sound on a set of clicky white chocs.

Those white chocs are attached to a ThumbsUp! v8 keyboard, a line that [Sasha K.] designed. His daily driver boards are on v9 and v10, but the caps were getting jammed up because of the spacing on those. So instead, he used v8 which has Cherry MX spacing but also supports chocs.

As you can see, there is not much to the adapter, which essentially plugs the Selectric keycap’s slot and splits the force into the electrical outlet-style pair of holes that chocs bear This feels like an easier problem to solve than making an adapter for MX-style switches. What do you think?

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Cheap Fiber Optic Wand Toy Becomes Tiny Weird Display

February 28, 2025 by Lewin Day 9 Comments

If you’ve ever seen those cheap LED fiber optic wands at the dollar store, you’ve probably just thought of them as a simple novelty. However, as [Ancient] shows us, you can turn them into a surprisingly nifty little display if you’re so inclined.

The build starts by removing the fiber optic bundle from the wand. One end is left as a round bundle. At the other end, the strands are then fed into plastic frames to separate them out individually. After plenty of tedious sorting, the fibers are glued in place in a larger rectangular 3D-printed frame, which holds the fibers in place over a matrix of LEDs. The individual LEDs of the matrix light individual fibers, which carry the light to the round end of the bundle. The result is a tiny little round display driven by a much larger one at the other end.

[Ancient] had hoped to use the set up for a volumetric display build, but found it too fragile to be fit for purpose. Still, it’s interesting to look at nonetheless, and a good demonstration of how fiber optics work in practice. As this display shows, you can have two glass fibers carrying completely different wavelengths of light right next to each other without issue.

We’ve featured some other great fiber optic hacks over the years, like this guide on making your own fiber couplings. Video after the break.

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Old IPad To New Screen

February 24, 2025 by Jenny List 5 Comments

Turning surplus LCD panels into stand-alone monitors with the help of a driver board is an established hack, and a search of eBay or AliExpress will turn up boards for almost any widely available panel. [Drygol] has a couple of old iPad screens, and has done exactly this with them. What makes these two projects stand aside from the crowd is their attention to detail, instead of creating a hacky monitor this is almost something you might buy as a product.

For a start, both screens sit in very smart 3D printed cases. Behind them is the LCD driver, and perhaps this is where many people might leave it. But the point of an iPad is portability, so the first one receives a suitably large lithium polymer battery and its associated electronics. As such a thing is of limited use without a battery level monitor, so one is mounted flush with the case on the outside. The final touch is a Bluetooth audio board and speaker, making an all-in-one peripheral we’d be happy to carry with us.

The second screen is a slimmer version of the first case, with a different board that has an onboard audio channel. It’s mounted in a stand with a MiSter FPGA emulator, for a very neat and compact desktop set-up.

This project shows what can be done with these screens, and raises the bar. All the files are included, so it should be possible to make your own. We expect someone might stick a Raspberry Pi in there, to make… something like an iPad.

This isn’t the first time we’ve seen an iPad screen mod.

Keebin’ With Kristina: The One With All The Green Keyboards

February 24, 2025 by Kristina Panos 2 Comments

Okay, you have to see the gallery to appreciate it, but this keyboard was designed to resemble a red cedar tree with the green shell and wood bottom and the copper PCB showing through the tree cutouts on the sides.

A lovely green split keyboard with PlayStation buttons. — Image by [WesternRedCdar] via reddit

But you know why I chose this picture — those PS2 buttons. According to [WesternRedCdar] they are just for fun, although they do allow for pressing Ctrl and Alt at the same time with a single thumb.

Oh, and are those Nintendo Switch joysticks above the PS2 buttons? Those are for the mouse and vertical/horizontal scrolling. Honestly, this seems like a great amount of thumb controls. The basics are there (presumably), and there isn’t any thumb-extending excess, like keys on the insides by the mouse.

This bad mama jama runs on an RP2040 and has 50 hand-wired Cherry Brown switches plus the PS2 buttons. In the build guide, you can read all about [WesternRedCdar]’s troubles with integrating those. The Nintendo Switch joysticks weren’t terribly easy, either, since the ribbon connector can’t be soldered directly.

The final issue was one of weight. Since many of the switches stand quite tall, it sort of jostles the keyboard to actuate them. [WesternRedCdar] opined that that the ideal solution would have been to use metal base plates instead of wood, but took care of the issue by adding layers of 1/8″ steel flat bar inside the case.

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In A World Without USB…

February 19, 2025 by Al Williams 26 Comments

It is easy to forget that many technology juggernauts weren’t always the only game in town. Ethernet seems ubiquitous today, but it had to fight past several competing standards. VHS and Blu-ray beat out their respective competitors. But what about USB? Sure, it was off to a rocky start in the beginning, but what was the real competition at that time? SCSI? Firewire? While those had plusses and minuses, neither were really in a position to fill the gap that USB would inhabit. But [Ernie Smith] remembers ACCESS.bus (or, sometimes, A.b) — what you might be using today if USB hadn’t taken over the world.

Back in the mid-1980s, there were several competing serial bus systems including Apple Desktop Bus and some other brand-specific things from companies like Commodore (the IEC bus) and Atari (SIO). The problem is that all of these things belong to one company. If you wanted to make, say, keyboards, this was terrible. Your Apple keyboard didn’t fit your Atari or your IBM computer. But there was a very robust serial protocol already in use — one you’ve probably used yourself. IIC or I2C (depending on who you ask).

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