A PCB business card with a built-in 4x4 tic-tac-toe game on the back.

2024 Business Card Contest: A Game For Two

May 30, 2024 by 2 Comments

If you want to make a good first impression on someone, it seems like the longer you can keep them talking, the better. After all, if they want to keep talking, that’s a pretty good sign that even if you don’t become business partners, you might end up friends. What better way to make an acquaintance than over a friendly game of tic-tac-toe?

This one will probably take them by surprise, being a 4×4 matrix rather than the usual 3×3, but that just makes it more interesting. The front of the card has all the usual details, and the back is a field of LEDs and micro switches. Instead of using X and O, [Edison Science Corner] is using colors — green for player one, and red for player two. Since playing requires the taking of turns, the microcontroller lights up green and red with alternating single-button presses.

Speaking of, the brains of this operation is an ATMega328P-AU programmed with Arduino. If you’d like to make your own tic-tac-toe business card, the schematic, BOM, and code are all available. Be sure to check out the build and demo video after the break.

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Pixel Graphics From An HD44780, By Cutting Wires

May 29, 2024 by 12 Comments

[Felipe Tavares] wasn’t satisfied with the boring default fonts on an HD44780-based display. And while you can play some clever tricks with user-defined characters, if you want to treat the display as an array of pixels, you’ve got to get out your scalpel and cut up a data line.

The hack builds on work from [MisterHW] who documented the bits going from the common display driver to the display, and suggested that by cutting the data line and sending your own bits, you could send arbitrary graphics. The trick was to make sure that they’re in sync with the display, though, which means reading the frame sync line in user code.

This done, it looks like [Felipe] has it working! If you can read Rust for the ESP32, he has even provided us with a working demo of the code that makes it work.

We can’t help but wonder if it’s not possible to go even lower-level and omit the HD44780 entirely. Has anyone tried driving one of these little LCD displays directly from a microcontroller, essentially implementing the HD44780 yourself?

Any way you slice it, this is a cool hack, and it opens up the doors to DOOM, or as [MisterHW] suggests, Bad Apple on these little displays . If you do it, we want to see it.

If your needs aren’t so exotic, the classic HD44780 display is a piece of cake to get working, and an invaluable tool in anyone’s toolbox.

Looking Forward To EMF 2024

May 29, 2024 by 10 Comments

It’s that time of year again when some parts of our community travel out into the countryside to spend time with each other under canvas in a field somewhere with power and fast internet — it’s hacker camp season. Here in Europe that means it’s the turn of the British hackers to have the year’s large event, in the form of the latest incarnation of Electromagnetic Field. We’ll be there, camera and microphone in hand, and with luck we’ll be able to bring you a flavour of the event.

The atmosphere that comes from being in the company of several thousand like minds is stimulating enough, but what makes these outdoor events special is that the villages become so much more than simply a group of geeks at a table with their laptops. Where else can one find a tea room run by a hackerspace except courtesy of MK Makerspace, or a fully functional pop-up motor racing circuit from Hacky Racers?

This year’s event badge is an interesting one, the ESP32-S3 powered and hexagon-shaped Tildagon. It’s a bold attempt to redefine the event badge away from a one-off trinket into one that lasts across multiple events, with custom “Hexpansions” like the petals on a flower, intended to have new ones appear on an event by event basis.

If you’re going to be at EMF then maybe we can join you for a pint, otherwise we’ll be bringing you the best that we find there. To whet your appetite, here’s something of the last one.

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Hackaday Links: May 26, 2024

May 26, 2024 by 5 Comments

Another day, another crop of newly minted minimal astronauts, as Blue Origin’s New Shepard made a successful suborbital flight this week. Everything seemed to go according to plan, at least until right at the end, when an “unexpected foliage contingency” made astronaut egress a little more complicated than usual. The New Shepard capsule had the bad taste to touch down with a bit of West Texas shrubbery directly aligned with the hatch, making it difficult to find good footing for the platform used by the astronauts for the obligatory “smile and wave” upon exiting. The Blue Origin ground crew, clad in their stylish black and blue outfits that must be murderously impractical in the West Texas desert, stamped down the brush to place the stairway, but had a lot of trouble getting it to sit straight. Even with the impromptu landscaping, the terrain made it tough to get good footing without adding random bits of stuff to prop up one leg, an important task considering that one of the new astronauts was a 90-year-old man. It seems pretty short-sighted not to have adjustable legs on the stairway, but there it is.

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How Do You Fill The 1N34 Void?

May 26, 2024 by 31 Comments

The germanium point contact diode, and almost every semiconductor device using germanium, is now obsolete. There was a time when almost every television or radio would have contained one or two of them, but the world has moved on from both analogue broadcasting and discrete analogue electronics in its lower-frequency RF circuitry. [TSBrownie] is taking a look at alternatives to the venerable 1N34A point-contact diode in one of the few places a point-contact diode makes sense, the crystal radio.

In the video below the break, he settles on a slightly more plentiful Eastern European D9K as a substitute after trying a silicon rectifier (awful) and a Schottky diode (great in theory, not so good in practice). We’ve trodden this path in the past and settled on a DC bias to reduce the extra forward voltage needed for a 1N4148 silicon diode to conduct because, like him, we found a Schottky disappointing.

The 1N34 is an interesting component, and we profiled its inventor a few years ago. Meanwhile, it’s worth remembering that sometimes, we just have to let old parts go.

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2024 Business Card Challenge: Adding Some Refinement To Breadboard Power Supplies

May 26, 2024 by 6 Comments

For small electronics projects, prototyping a design on a breadboard is a must to iron out kinks in the design and ensure everything works properly before a final version is created. The power supply for the breadboard is often overlooked, with newcomers to electronics sometimes using a 9V battery and regulator or a cheap USB supply to get a quick 5V source. We might eventually move on to hacking together an ATX power supply, or the more affluent among us might spring for a variable, regulated bench supply, but this power supply built specifically for breadboards might thread the needle for this use case much better than other options.

The unique supply is hosted on a small PCB with two breakout rails that connect directly to the positive and negative pins on a standard-sized breadboard. The power supply has two outputs, each of which can output up to 24V DC and both are adjustable by potentiometers. To maintain high efficiency and lower component sizes, a switch-mode design is used to provide variable DC voltage. A three-digit, seven-segment display at the top of the board keeps track of whichever output the user selects, and the supply itself can be powered by a number of inputs, including USB-C or lithium batteries.

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FLOSS Weekly Episode 784: I’ll Buy You A Poutine

May 22, 2024 by No comments

This week Jonathan Bennett and Dan Lynch talk with François Proulx about Poutine, the Open Source security scanner for build pipeline vulnerabilities. This class of vulnerability isn’t as well known as it should be, and threatens to steal secrets, or even allow for supply chain attacks in FLOSS software.

Poutine does a scan over an organization or individual repository, looking specifically for pipeline issues. It runs on both GitHub and GitLab, with more to come!

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