Misc Hacks

4108 Articles

Inside An Edison Phonograph

April 5, 2025 by 14 Comments

If you think of records as platters, you are of a certain age. If you don’t remember records at all, you are even younger. But there was a time when audio records were not flat — they were drums, which was how the original Edison phonograph worked. [Our Own Devices] did a video earlier showing one of these devices, but since it was in a museum, he didn’t get to open it up. Lucky for us, he now has one of his own, and we get to see inside in the video below.

Ironically, Edison was deaf yet still invented the phonograph. While he did create the working phonograph — his self-identified most important invention — the original invention wasn’t commercially viable. You could record and playback audio on tin foil wrapped around a drum. But you couldn’t remove the foil without destroying it.

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Shrinking Blinky As Far As Possible

April 1, 2025 by 39 Comments

Many of us know the basic Blink Arduino sketch, or have coded similar routines on other microcontrollers. Flashing an LED on and off—it doesn’t get much simpler than that. But how big should a blink sketch be? Or more importantly, how small could you get it? [Artful Bytes] decided to find out.

The specific challenge? “Write a program that runs on a microcontroller and blinks an LED. The ON and OFF times should be as close to 1000 ms as possible.” The challenge was undertaken using a NUCLEO-L432KC Cortex-M4 with 256 K of flash and 64 K of RAM.

We won’t spoil the full challenge, but it starts out with an incredibly inefficient AI & cloud solution. [Artful Bytes] then simplifies by switching to an RTOS approach, before slimming down further with C, assembly, and then machine code. The challenge was to shrink the microcontroller code as much as possible. However, you might notice the title of the video is “I Shrunk Blinky to 0 Bytes.” As it turns out, if you eliminate the digital code-running hardware entirely… you can still blink an LED with analog hardware. So, yes. 0 bytes is possible.

We’ve featured the world’s smallest blinky before, too, but in a physical sense rather than with regards to code size.

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A Music Box Commanded By NFC Tags

March 31, 2025 by 7 Comments

[Luca Dentella] recently encountered a toy, which was programmed to read different stories aloud based on the figurine placed on top. It inspired him to build an audio device using the same concept, only with music instead of children’s stories.

The NFC Music Player very much does what it says on the tin. Present it with an NFC card, and it will play the relevant music in turn. An ESP32 WROOM-32E lives at the heart of the build, which is hooked up over I2S with a MAX98357A Class D amplifier for audio output. There’s also an SD card slot for storing all the necessary MP3s, and a PN532 NFC reader for reading the flash cards that activate the various songs. Everything is laced up inside a simple 3D-printed enclosure with a 3-watt full range speaker pumping out the tunes.

It’s an easy build, and a fun one at that—there’s something satisfying about tossing a flash card at a box to trigger a song. Files are on Github for the curious. We’ve featured similar projects before, like the Yaydio—a fun NFC music player for kids. Video after the break.

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3D-Printed Scanner Automates Deck Management For Trading Card Gamers

March 26, 2025 by 11 Comments

Those who indulge in trading card games know that building the best deck is the key to victory. What exactly that entails is a mystery to us muggles, but keeping track of your cards is a vital part of the process, one that this DIY card scanner (original German; English translation) seeks to automate.

At its heart, [Fraens]’ card scanner is all about paper handling, which is always an engineering task fraught with peril. Cards like those for Magic: The Gathering and other TCGs are meant to be handled by human hands, and automating the task of flipping through them presents some challenges. [Fraens] uses a pair of motorized 3D-printed rollers with O-rings to form a conveyor belt that can pull one card at a time off the bottom of a deck. An adjustable retaining roller made from the most adorable linear bearing we’ve ever seen ensures that only one card at a time is pulled from the hopper onto an imaging platen. An adjustable mount holds a smartphone to take a picture of the card, which is fed into an app that extracts all the details and categorizes the cards in the deck.

Aside from the card handling mechanism, there are some pretty slick details to this build. The first is that [Fraens] noticed that the glossy finish on some cards interfered with scanning, leading him to add a diffused LED ringlight to the rig. If an image isn’t scannable, the light goes through a process of dimming and switching colors until a good scan is achieved. Also, to avoid the need to modify the existing TCG deck management app, [Fraens] added a microphone to the control side of the scanner that listens for the sounds the app makes when it scans cards. And if Magic isn’t your thing, the basic mechanism could easily be modified to scan everything from business cards to old family photos.

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PPS Is The Hottest USB-C Feature You Didn’t Know About

March 24, 2025 by 28 Comments

USB Power Delivery is widely considered to be a good thing. It’s become relatively standard, and is a popular way for makers to easily power their projects at a number of specific, useful voltages. However, what you may not know is that it’s possible to get much more variable voltages out of some USB chargers out there. As [GreatScott!] explains, you’ll want to meet USB-C PPS.

PPS stands for Programmable Power Supply. It’s a method by which a USB-C device can request variable voltage and current delivery on demand. Unlike the Power Delivery standard, you’re not limited to set voltages at tiers of 5V, 9V, 15V and 20V. You can have your device request the exact voltage it wants, right from the charger.  Commercially, it’s most typically used to allow smartphones to charge as fast as possible by getting the optimum voltage to plumb into the battery. However, with the right techniques, you can use PPS to get a charger to output whatever voltage you want, from 3.3 V to 21 V, for your own nefarious purposes. You can choose a voltage in 20 mV increments, and even set a current limit in 50 mA increments. Don’t go mad with power, now.

However, there’s a hitch. Unlike USB PD, there isn’t yet a whole ecosystem of $2 PPS breakout boards ready to gloop into your own little projects. As [GreatScott!] suggests, if you want to use PPS, you might want to take a look at the AP33772S IC. It’s a USB PD3.1 Sink Controller. You can command it over I2C to ask for the voltage and current you want. If that’s too hard, though, [CentyLab] has a solution on Tindie to get you going faster. It’s also got some exciting additional functionality—like USB-C AVS support. It offers higher voltage and more power, albeit with less resolution, but chargers with this functionality are quite obscure at this stage.

We’ve actually touched on PPS capability before in our exploration of the magic that is USB-C Power Delivery. Video after the break.

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The SNES Seems To Be Getting Faster Over Time

March 24, 2025 by 24 Comments

Every Super Nintendo console should run at the same speed. They were all built in factories with the same components so they should all operate at the steady clip mandated by Nintendo all those years ago. Except, apparently, the SNES is speeding up as it gets older.

The matter was brought to the public’s attention by the [TASBot] team, a group within the speedrunning community. If anyone was going to notice vintage consoles suddenly running a hair faster, you could bet it would be the speedrunners. Soon enough, a call was put out to crowdsource some data. Submitters were asked to run a set piece of code to test the DSP sample rate on consoles when cold and warm, to get the best idea of what was going on.

As reported by Ars Technica, the group seems to have pinned down the problem to the SNES’s Audio Processing Unit. It’s supposed to run at 24.576 MHz, with a sample rate of 32,000 Hz. However, over the years, emulator developers and speedrunners had noticed that 32,040 Hz seemed to be a more realistic figure for what real consoles were actually running the DSP sample rate at. Developers found that building emulators to run the DSP at this rate was important to run commercial games as expected, suggesting the hardware might have always been a little faster than expected.

However, more recently, it seems that the average speed of the DSP sample rate has increased further. The average result collected by [TASBot] from modern consoles is 32,076 Hz. What’s more interesting is the range of submitted figures—from 31,976 Hz to 32,349 Hz. It seems that the DSP’s ceramic resonator—used instead of a quartz crystal—might degrade over time, causing the speedup. [TASBot] team members also tested temperature changes, but only found a 32 Hz variation from a frozen SNES to one at room temperature.

The fact that console components degrade over time isn’t exactly news; we’ve featured plenty of articles on leaky batteries and corroded traces. Still, for speedrunners, the idea that the hardware standard itself can shift over time? It’s like feeling quicksand under your feet. What even is reality anymore?

[Thanks to s7726 for the tip!]

Microscopic view of chiral magnetic material

Twisting Magnetism To Control Electron Flow

March 22, 2025 by 11 Comments

If you ever wished electrons would just behave, this one’s for you. A team from Tohoku, Osaka, and Manchester Universities has cracked open an interesting phenomenon in the chiral helimagnet α-EuP3: they’ve induced one-way electron flow without bringing diodes into play. Their findings are published in the Proceedings of the National Academy of Sciences.

The twist in this is quite literal. By coaxing europium atoms into a chiral magnetic spiral, the researchers found they could generate rectification: current that prefers one direction over another. Think of it as adding a one-way street in your circuit, but based on magnetic chirality rather than semiconductors. When the material flips to an achiral (ferromagnetic) state, the one-way effect vanishes. No asymmetry, no preferential flow. They’ve essentially toggled the electron highway signs with an external magnetic field. This elegant control over band asymmetry might lead to low-power, high-speed data storage based on magnetic chirality.

If you are curious how all this ties back to quantum theory, you can trace the roots of chiral electron flow back to the early days of quantum electrodynamics – when physicists first started untangling how particles and fields really interact.

There’s a whole world of weird physics waiting for us. In the field of chemistry, chirality has been covered by Hackaday, foreshadowing the lesser favorable ways of use. Read up on the article and share with us what you think.