Save Your USB-C Plugs From Oblivion

October 11, 2025 by Jenny List 59 Comments

USB-C as the “One Cable To Rule Them All” has certainly been a success. While USB-A is still around for now, most of us have breathed a hefty sigh of relief with the passing of micro-USB and the several display and power standards it replaces. It’s not without its minor issues though. One of them is that it’s as susceptible as any other cable to a bit of strain. For that, we think [NordcaForm]’s 3D-printed USB-C cable strain relief is definitely a cut above the rest.

Waxing lyrical about a simple 3D printed model might seem overkill for Hackaday, and it’s true, it’s not something we do often, but as Hackaday writers travel around with plenty of USB-C connected peripherals, we like the design of this one. It’s flexible enough to be useful without resorting to exotic filaments, and since it’s available in a few different forms with curved or straight edges, we think it can find a place in many a cable setup. Certainly more of an everyday carry than a previously featured 3D print. If you want to learn more about USB C, we have a whole series of posts for you to binge read.

A Casio Toy Synth Is Ready To ROCK!

October 11, 2025 by Jenny List 6 Comments

There is likely to be more than one of you who has eyed up a child’s toy synthesizer in a second hand store, and considered making something more impressive with it. In many cases these instruments are underwhelming, having a very small subset of functions based into their black-epoxy-blob microcontrollers.

[Make Something] found a Casio toy synth that has a few more functions than the average model, and with the addition of some extra effects electronics and a beautifully made case, turned it into an altogether more interesting instrument.

Most of the video has an element of workshop porn about it, as he makes a very nice Moog-style console case for it, a task made easier by an impressive array of CNC tools. The electronics are slightly more interesting, being a selection of cheap guitar pedals gutted and combined with a cheap tube preamp board. The result is a machine capable of some far more interesting sounds

We think many Hackaday readers would be able to repeat these functions from scratch without the pedals, and while the case is a thing of beauty it’s likely a decent job could be done with a little less finesse on more commonplace tools. Perhaps it’s worth giving those toy synths a second look, because they really can be had for pennies if you look hard enough. Perhaps it’s an easier option than a previous toy musical upgrade.

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The Electret Preamp You Might Need

October 11, 2025 by Jenny List 18 Comments

Electret capsules can be found in some of the highest quality microphones for studio use, as well as in some of the very cheapest microphone capsules on the market. More care and attention has gone into the high-end capsule and its associated circuitry than the cheap one, but is it still possible to get good quality from something costing under a dollar? [Mubarak Basha] thinks so, and has designed a preamp circuit to get the best from a cheap electret capsule.

These capsules may be cheap, but with the addition of a low voltage supply, a resistor, and a capacitor, their internal FET delivers a decent enough input to many a project. To improve on that will need a bit of effort, and in this the preamp delivers by taking care to match impedance, impose a carefully chosen frequency response, and just the right gain to derive a line level output from the electret’s level. It’s hardly a complex circuit, but that’s not always necessary.

As always in these situations, without appropriate test equipment it’s difficult to gauge quality. We’d say this though, if you make one of these and it falls short, you won’t have spent much. Meanwhile if you’re curious about electrets, here’s our guide.

A Function Generator From The Past

October 10, 2025 by Jenny List 11 Comments

It’s always a pleasure to find a hardware hacker who you haven’t seen before, and page back through their work. [Bettina Neumryr]’s niche comes in building projects from old electronics magazines, and her latest, a function generator from the British Everyday Electronics magazine in April 1983, is a typical build.

The project uses the XR2206 function generator chip, a favourite of the time. It contains a current controlled oscillator and waveform shaper, and can easily produce square, triangle, and sine waves. It was always a puzzle back in the day why this chip existed as surely the global market for function generators can’t have been that large, however a little bit of background reading for this write-up reveals that its intended application was for producing frequency-shift-keyed sinusoidal tones.

The two PCBs on the bench, with a multimeter — Yellow-stained boards for the win!

The EE project pairs the XR2206 with an op-amp current generator to control the frequency, and another op-amp as an amplifier and signal conditioner. The power supply is typical of the time too, a mains transformer, rectifier, and linear regulators. There are a pair of very period PCBs supplied as print-outs in the magazine for home etching. This she duly does, though with toner transfer which would have been unheard of in 1983. After a few issues with faulty pots and a miswired switch, she has a working function generator which she puts in a very period project box.

It’s interesting to look at this and muse on what’s changed in electronic construction at our level in the last four decades. The PCB is single sided and has that characteristic yellow of ferric chloride etching, it takes up several times the space achievable with the same parts on the professionally-made dual-sided board designed using a modern PCB CAD package we’d use today. A modern take on the same project would probably use a microcontroller and a DAC, and a small switch-mode supply for less money than that transformer would provide the power. But we like the 1983 approach, and we commend [Bettina] for taking it on. The full video is below the break.

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Hackaday Podcast Episode 341: Qualcomm Owns Arduino, Steppers Still Dominate 3D Printing, And Google Controls Your Apps

October 10, 2025 by Jenny List 2 Comments

The nights are drawing in for Europeans, and Elliot Williams is joined this week by Jenny List for an evening podcast looking at the past week in all things Hackaday. After reminding listeners of the upcoming Hackaday Supercon and Jawncon events, we take a moment to mark the sad passing of the prolific YouTuber, Robert Murray-Smith.

Before diving into the real hacks, there are a couple of more general news stories with an effect on our community. First, the takeover of Arduino by Qualcomm, and what its effect is likely to be. We try to speculate as to where the Arduino platform might go from here, and even whether it remains the player it once was, in 2025. Then there’s the decision by Google to restrict Android sideloading to only approved-developer APKs unless over ADB. It’s an assault on a user’s rights over their own hardware, as well as something of a blow to the open-source Android ecosystem. What will be our community’s response?

On more familiar territory we have custom LCDs, algorithmic art, and a discussion of non-stepper motors in 3D printing. Even the MakerBot Cupcake makes an appearance. Then there’s a tiny RV, new creative use of an ESP32 peripheral, and the DVD logo screensaver, in hardware. We end the show with a look at why logic circuits use the voltages they do. It’s a smorgasbord of hacks for your listening enjoyment.

Download yourself an MP3 even without a Hackaday Listeners’ License.

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Inside A Germanium Transistor

October 10, 2025 by Jenny List 9 Comments

The first transistors were point contact devices, not far from the cats-whiskers of early radio receivers. They were fragile and expensive, and their performance was not very high. The transistor which brought the devices to a mass audience through the 1950s and 1960s was the one which followed, the alloy diffusion type. [Play With Junk] has a failed OC71 PNP alloy diffusion transistor, first introduced in 1957, and has cracked it open for a closer look.

Inside the glass tube is a small wafer of germanium crystal, surrounded by silicone grease. It forms the N-type base of the device, with the collector and emitter being small indium beads fused into the germanium. The junctions were formed by the resulting region of germanium/indium alloy. The outside of the tube is pained black because the device is light-sensitive, indeed a version of this transistor without the paint was sold as the OCP71 phototransistor.

These devices were leaky and noisy, with a low maximum frequency and low gain. But they were reliable and eventually affordable, so some of us even cut our electronic teeth on them.

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Google Japan Turn Out Another Keyboard, And It’s A Dial

October 9, 2025 by Jenny List 20 Comments

There’s a joke that does the rounds, about a teenager being given a dial phone and being unable to make head nor tail of it. Whether or not it’s true, we’re guessing that the same teen might be just a stumped by this year’s keyboard oddity from Google Japan. It replaces keys with a series of dials that work in the same way as the telephone dial of old. Could you dial your way through typing?

All the files to make the board, as well as a build guide, are in the GitHub repository linked above, but they’ve also released a promotional video that we’ve put below the break. The dials use 3D printed parts, and a rotary encoder to detect the key in question. We remember from back in the day how there were speed dialing techniques with dial phones, something we’ve probably by now lost the muscle memory for.

We like this board for its quirkiness, and while it might become a little tedious to type a Hackaday piece on it, there might be some entertainment for old-timers in watching the youngsters figuring it out. If you’re hungry for more, we’ve covered them before.

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