PCB Business Card Plays Pong, Attracts Employer

August 13, 2025 by 12 Comments

Facing the horrifying realization that he’s going to graduate soon, EE student [Colin Jackson] AKA [Electronics Guy] needed a business card. Not just any business card: a PCB business card. Not just any PCB business card: a PCB business card that can play pong.

[Colin] was heavily inspired by the card [Ben Eater] was handing out at OpenSauce last year, and openly admits to copying the button holder from it. We can’t blame him: the routed-out fingers to hold a lithium button cell were a great idea. The original idea, a 3D persistence-of-vision display, was a little too ambitious to fit on a business card, so [Colin] repurposed the 64 LED matrix and STM32 processor to play Pong. Aside from the LEDs and the microprocessor, it looks like the board has a shift register to handle all those outputs and a pair of surface-mount buttons.

Of course you can’t get two players on a business card, so the microprocessor is serving as the opponent. With only 64 LEDs, there’s no room for score-keeping — but apparently even the first, nonworking prototype was good enough to get [Colin] a job, so not only can we not complain, we offer our congratulations.

The video is a bit short on detail, but [Colin] promises a PCB-business card tutorial at a later date. If you can’t wait for that, or just want to see other hackers take on the same idea, take a gander at some of the entries to last year’s Business Card Challenge. Continue reading “PCB Business Card Plays Pong, Attracts Employer” →

Ore Formation: Introduction And Magmatic Processes

August 13, 2025 by 10 Comments

Hackaday has a long-running series on Mining and Refining, that tracks elements of interest on the human-made road from rocks to riches. What author Dan Maloney doesn’t address in that series is the natural history that comes before the mine. You can’t just plunk down a copper mine or start squeezing oil from any old stone, after all: first, you need ore. Ore has to come from somewhere. In this series, we’re going to get down and dirty into the geology of ore-forming processes to find out from wither come the rocks that hold our elements of interest.

What’s In an Ore?

Though we’re going to be talking about Planetary Science in this series, we should recognize the irony that “ore” is a word without any real scientific meaning. What distinguishes ore from other rock is its utility to human industry: it has elements or compounds, like gems, that we want, and that we think we can get out economically. That changes over time, and one generation’s “rock” can be another generation’s “ore deposits”. For example, these days prospectors are chasing copper in porphyry deposits at concentrations as low as 1000 ppm (0.1%) that simply were not economic in previous decades. The difference? Improvements in mining and refining, as well as a rise in the price of copper. Continue reading “Ore Formation: Introduction And Magmatic Processes” →

Josef Prusa Warns Open Hardware 3D Printing Is Dead

August 13, 2025 by 141 Comments

It’s hard to overstate the impact desktop 3D printing has had on the making and hacking scene. It drastically lowered the barrier for many to create their own projects, and much of the prototyping and distribution of parts and tools that we see today simply wouldn’t be possible via traditional means.

What might not be obvious to those new to the game is that much of what we take for granted today in the 3D printing world has its origins in open source hardware (OSHW). Unfortunately, [Josef Prusa] has reason to believe that this aspect of desktop 3D printing is dead.

If you’ve been following 3D printing for awhile, you’ll know how quickly the industry and the hobby have evolved. Just a few years ago, the choice was between spending the better part of $1,000 USD on a printer with all the bells and whistles, or taking your chances with a stripped-down clone for half the price. But today, you can get a machine capable of self calibration and multi-color prints for what used to be entry-level prices. According to [Josef] however, there’s a hidden cost to consider.

Continue reading “Josef Prusa Warns Open Hardware 3D Printing Is Dead” →

A red Sony PSP gaming console is shown, displaying the lines “Audio Mechanica,” “Brek Martin 2006-2025,” and “Waiting for Headphones.”

Running Guitar Effects On A PlayStation Portable

August 13, 2025 by 8 Comments

If your guitar needs more distortion, lower audio fidelity, or another musical effect, you can always shell out some money to get a dedicated piece of hardware. For a less conventional route, though, you could follow [Brek Martin]’s example and reprogram a handheld game console as a digital effects processor.

[Brek] started with a Sony PSP 3000 handheld, with which he had some prior programming experience, having previously written a GPS maps program and an audio recorder for it. The PSP has a microphone input as part of the connector for a headset and remote, though [Brek] found that a Sony remote’s PCB had to be plugged in before the PSP would recognize the microphone. To make things a bit easier to work with, he made a circuit board that connected the remote’s hardware to a microphone jack and an output plug.

[Brek] implemented three effects: a flanger, bitcrusher, and crossover distortion. Crossover distortion distorts the signal as it crosses zero, the bitcrusher reduces sample rate to make the signal choppier, and the flanger mixes the current signal with its variably-delayed copy. [Brek] would have liked to implement more effects, but the program’s lag would have made it impractical. He notes that the program could run more quickly if there were a way to reduce the sample chunk size from 1024 samples, but if there is a way to do so, he has yet to find it.

If you’d like a more dedicated digital audio processor, you can also build one, perhaps using some techniques to reduce lag.

Continue reading “Running Guitar Effects On A PlayStation Portable” →

That’s No Moon, Er, Selectric

August 12, 2025 by 5 Comments

If you learned to type anytime in the mid-part of the 20th century, you probably either had or wanted an IBM Selectric. These were workhorses and changed typing by moving from typebars to a replaceable element. They were expensive, though worth it since many of them still work (including mine). But few of us could afford the $1,000 or more that these machines cost back in the day, especially when you consider that $1,000 was enough to buy a nice car for most of that time. [Tech Tangents] looks at something different: a clone Selectric from the sewing machine and printer company Juki.

The typewriter was the brainchild of [Thomas O’Reilly]. He sold typewriters and knew that a $500 compatible machine would sell. He took the prototype to Juki, which was manufacturing typewriters for Olivetti at the time.

Continue reading “That’s No Moon, Er, Selectric” →

Creating A New Keyboard Flex For An Old Calculator

August 12, 2025 by 20 Comments

[Menadue] had a vintage Compucorp 326 calculator with an aging problem. Specifically, the flex cable that connects the button pad had turned corroded over time. However, thanks to the modern PCB industrial complex, replacing the obscure part was relatively straightforward!

The basic idea was simple enough: measure the original flex cable, and recreate it with the flat-flex PCB options available at many modern PCB houses that cater to small orders and hobbyists. [Menadue] had some headaches, having slightly misjudged the pitch of the individual edge-connector contacts. However, he figured that if lined up just right, it was close enough to still work. With the new flex installed, the calculator sprung into life…only several keys weren’t working. Making a new version with the correct pitch made all the difference, however, and the calculator was restored to full functionality.

It goes to show that as long as your design skills are up to scratch, you can replace damaged flex-cables in old hardware with brand new replacements. There’s a ton of other cool stuff you can do with flex PCBs, too.

Continue reading “Creating A New Keyboard Flex For An Old Calculator” →

Flip card

LEDs That Flow: A Fluid Simulation Business Card

August 12, 2025 by 18 Comments

Fluid-Implicit-Particle or FLIP is a method for simulating particle interactions in fluid dynamics, commonly used in visual effects for its speed. [Nick] adapted this technique into an impressive FLIP business card.

The first thing you’ll notice about this card is its 441 LEDs arranged in a 21×21 matrix. These LEDs are controlled by an Raspberry Pi RP2350, which interfaces with a LIS2DH12TR accelerometer to detect card movement and a small 32Mb memory chip. The centerpiece is a fluid simulation where tilting the card makes the LEDs flow like water in a container. Written in Rust, the firmware implements a FLIP simulation, treating the LEDs as particles in a virtual fluid for a natural, flowing effect.

This eye-catching business card uses clever tricks to stay slim. The PCB is just 0.6mm thick—compared to the standard 1.6mm—and the 3.6mm-thick 3.7V battery sits in a cutout to distribute its width across both sides of the board. The USB-C connection for charging and programming uses clever PCB cuts, allowing the plug to slide into place as if in a dedicated connector.

Inspired by a fluid simulation pendant we previously covered, this board is just as eye-catching. Thanks to [Nick] for sharing the design files for this unique business card. Check out other fluid dynamics projects we’ve featured in the past.