PCB Business Card Plays Pong, Attracts Employer

August 13, 2025 by Tyler August 8 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” →

Creating A New Keyboard Flex For An Old Calculator

August 12, 2025 by Lewin Day 19 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” →

Design Review: LattePanda Mu NAS Carrier

August 12, 2025 by Arya Voronova 15 Comments

It is a good day for design review! Today’s board is the MuBook, a Lattepanda Mu SoM (System-on-Module) carrier from [LtBrain], optimized for a NAS with 4 SATA and 2 NVMe ports. It is cheap to manufacture and put together, the changes are non-extensive but do make the board easier to assemble, and, it results in a decent footprint x86 NAS board you can even order assembled at somewhere like JLCPCB.

This board is based on the Lite Carrier KiCad project that the LattePanda team open-sourced to promote their Mu boards. I enjoy seeing people start their project from a known-working open-source design – they can save themselves lots of work, avoid reinventing the wheel and whole categories of mistakes, and they can learn a bunch of design techniques/tips through osmosis, too. This is a large part of why I argue everyone should open-source their projects to the highest extent possible, and why I try my best to open-source all the PCBs I design.

Let’s get into it! The board’s on GitHub as linked, already containing the latest changes.

Git’ting Better

I found the very first review item when downloading the repo onto my computer. It took a surprising amount of time, which led me to believe the repo contains a fair bit of binary files – something quite counterproductive to keep in Git. My first guess was that the repo had no .gitignore for KiCad, and indeed – it had the backups/ directory with a heap of hefty .zips, as well as a fair bit of stuff like gerbers and footprint/symbol cache files. I checked in with [LtBrain] that these won’t be an issue to delete, and then added a .gitignore from the Blepis project.

Continue reading “Design Review: LattePanda Mu NAS Carrier” →

Hacking Printed Circuit Board To Create Casing And Instrument Panels

August 9, 2025 by John Elliot V 11 Comments

Over on Hackaday.io our hackers [Angelo] and [Oscarv] are making a replica of the PDP-1. That is interesting in and of itself but the particularly remarkable feature of this project is its novel use of printed circuit boards for casing and instrument panels.

What does that mean in practice? It means creating a KiCad file with a PCB for each side of the case/panel. These pieces can then be ordered from a board house and assembled. In the video below the break you will see an example of putting such a case together. They use sticky tape for scaffolding and then finish things off by soldering the solder joints on each edge together.

Continue reading “Hacking Printed Circuit Board To Create Casing And Instrument Panels” →

The LumenPnP Pasting Utility: Never Buy Solder Stencils Again?

July 30, 2025 by John Elliot V 11 Comments

Over on his YouTube channel the vivacious [Stephen Hawes] tells us that we never need to buy solder stencils again!

A big claim! And he is quick to admit that his printed solder paste isn’t presently quite as precise as solder stencils, but he is reporting good success with his technique so far.

[Stephen] found that he could print PCBs with his fiber laser, populate his boards with his LumenPnP, and reflow with his oven, but… what about paste? [Stephen] tried making stencils, and in his words: “it sucked!” So he asked himself: what if he didn’t need a stencil? He built a Gerber processing, G-code generating, machine-vision implemented… website. The LumenPnP Pasting Utility: https://paste.opulo.io/

Continue reading “The LumenPnP Pasting Utility: Never Buy Solder Stencils Again?” →

Transparent PCBs Trigger 90s Nostalgia

July 25, 2025 by Lewin Day 42 Comments

What color do you like your microcontroller boards? Blue? Red? Maybe white or black? Sadly, all of those are about to look old hat. Why? Well, as shared by [JLCPCB], this transparent Arduino looks amazing.

The board house produced this marvel using its transparent flexible printed circuit (FPC) material. Basically, the stuff they use for ribbon cables and flex PCBs, just made slightly differently to be see-through instead of vaguely brown.

The circuit in question is a Flexduino, an Arduino clone specifically designed to work on flexible substrates. It looks particularly good on this transparent material, with the LEDs glowing and the white silkscreen for contrast. If you like what you see, you can order your own circuits using this material directly from JLCPCB’s regular old order form.

Most of all, this project reminds us of the 1990s. Back then, you could get all kinds of games consoles and other electronics with transparent housings. There was the beloved PlayStation Crystal, while Nintendo did something similar with the N64 while adding a whole line of tinted color and charcoal versions too. Somehow seeing a bit of the inside of things is just cool. Even if, in some cases, it’s just to avoid smuggling in prisons.

It took decades before you could get custom PCBs quickly and easily. Now, board houses are competing for the enthusiast (consumer?) market, and competition is spurring development of crazy stuff like transparent and even glow in the dark PCBs. What next? We’re thinking edible, ROHS and WEEE be damned. Drop your thoughts in the comments.

Thanks to [George Graves] for the tip!

Software Defined Retro ROMs

July 19, 2025 by John Elliot V 6 Comments

Here’s something fun from our hacker [Piers]: Software Defined ROMs.

In this series of three videos, [Piers] runs us through what a software defined ROM is, how to make them, and then how to use them.

As [Piers] explains, one frustration a retro technician will face is a failed ROM chip. In the era he’s interested in, there are basically three relevant kinds of ROM chip, all 24-pin Dual Inline Package (DIP):

2364 ROM chip: 8KB; 1x chip-select line
2332 ROM chip: 4KB; 2x chip-select lines
2316 ROM chip: 2KB; 3x chip-select lines

Continue reading “Software Defined Retro ROMs” →