Day: January 4, 2025

Nottingham Railway departure board in Hackspace

All Aboard The Hack Train: Nottingham’s LED Revival

January 4, 2025 by 3 Comments

Hackerspaces are no strangers to repurposing outdated tech, and Nottingham Hackspace happens to own one of those oddities one rarely gets their hands on: a railway departure board. Left idle for over a decade, it was brought back to life by [asjackson]. Originally salvaged around 2012, it remained unused until mid-2024, when [asjackson] decided to reverse-engineer it. The board now cycles between displaying Discord messages and actual train departures from Nottingham Railway Station every few minutes. The full build story can be found in this blog post.

The technical nitty-gritty is fascinating. Each side of the board contains 4,480 LEDs driven as two parallel chains. [asjackson] dove into its guts, decoding circuits, fixing misaligned logic levels, and designing custom circuit boards in KiCAD. The latest version swaps WiFi for a WizNet W5500 ethernet module and even integrates the Arduino Uno R4 directly into the board’s design. Beyond cool tech, the display connects to MQTT, pulling real-time train data and Discord messages via scripts that bridge APIs and custom Arduino code.

This board is a true gem for any hackerspace, even more so now it’s working. It waited for the exact mix of ingredients why hackerspaces exist in the first place: curiosity, persistence, and problem-solving. Nottingham Hackspace is home to a lot more, as we once wrote in this introductory article.If you don’t have room for the real thing, maybe set your sights a bit smaller.

Do you have a statement piece this cool in your hackerspace or your home? Tip us!

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Self Driving Like It’s 1993

January 4, 2025 by 16 Comments

In a stunning example of the Baader Meinhof effect, we’ve recently heard several times this week about events like the “carbage run.” That is, a motoring event where you can only buy some garbage car to compete. In the case of [Robbe Derks], the idea was to take a six-day journey to the polar circle in a car. But not just any car. It had to be at least 20 years old and cost less than €1000. That wasn’t hard enough for [Robbe] and friends. They also decided to make the car self-driving.

If you have a car that is new enough, this might not be as hard as it sounds. The OpenPilot project adds L2 self-driving features to about 275 car models. But probably not a 20-year-old junker or, in particular, a 1993 Volvo 940. [Robbe] took up the challenge and is doing a series of blog posts covering how it all worked.

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Close up of a Hornet Nest circuit board

PoE-Power Protection: The Hornet Nest Alarm Panel

January 4, 2025 by 30 Comments

Have you ever thought of giving new buzz to outdated wired alarm systems or saving money while upgrading your home security? The Hornet Nest Alarm Panel, to which hacker [Patrick van Oosterwijck] contributes, does just that. Designed for domotics enthusiasts, it offers 42 sensor zones and seamless integration with Home Assistant and ESPHome. This open-source gem uses the wESP32 board, which combines an ESP32 with Ethernet and Power over Ethernet (PoE) for robust, reliable connectivity. Check out the Crowd Supply campaign for details.

So what makes this Hornet Nest special? Besides its hackable nature, it repurposes existing wired sensors, reducing waste and cost. Unlike WiFi-dependent solutions, the PoE-powered ESP32 ensures stable performance, even in hard-to-reach locations. The optional USB programming port is genius—it’s there when you need it but doesn’t clutter the board when you don’t. With its isolated circuits, long-cable safety, and smart Ethernet, WiFi, and Bluetooth combination, this system ticks every DIY box.

Hackaday has featured other DIY PoE-powered projects, offering more inspiration for smart automation enthusiasts.

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How Crane Games Are Playing Claw Games With The Player

January 4, 2025 by 33 Comments

Fresh from AliExpress, [Big Clive] got another fascinating item to tear down: a crane claw, as used in those all too familiar carnival games. These games feature a claw the player moves into position above a pile of toys or other items. Lower the claw gently down in the hopes that it grabs the target item. In a perfect world, the claw will move your prize and deposit it, via a chute, into your waiting hands. Of course, everyone knows that these games are rigged and rely less on skill or luck than the way that they are programmed, but the way that this works is quite subtle, as you can see in the video below.

Despite how complex these crane claws may appear, they are simply solenoids, with the metal rod inside providing the claw action. The weight of the rod and claw section opens the claw via gravity. The strength of the claw is thus fully dependent on how strongly the solenoid is being driven, which, as [Clive] demonstrates, depends on the voltage and the duty cycle. At only 12V, the target plushie will easily slip away again as the claw barely has any strength, while at 24V, it’s pretty solid.

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Pi Pico Makes SSTV Reception A Snap

January 4, 2025 by 8 Comments

There’s a paradox in amateur radio: after all the time and effort spent getting a license and all the expense of getting some gear together, some new hams suddenly find that they don’t have a lot to talk about when they get in front of the mic. While that can be awkward, it’s not a deal-breaker by any means, especially when this Pi Pico SSTV decoder makes it cheap and easy to get into slow-scan television.

There’s not much to [Jon Dawson]’s SSTV decoder. Audio from a single-sideband receiver goes through a biasing network and into the Pico’s A/D input. The decoder can handle both Martin and Scottie SSTV protocols, with results displayed on a TFT LCD screen. The magic is in the software, of course, and [Jon] provides a good explanation of the algorithms he used, as well as some of the challenges he faced, such as reliably detecting which protocol is being used. He also implemented correction for “slant,” which occurs when the transmitter sample rate drifts relative to the receiver. Fixing that requires measuring the time it took to transmit each line and adjusting the timing of the decoder to match. The results are dramatic, and it clears up one of the main sources of SSTV artifacts.

We think this is a great build, and simple enough that anyone can try it. The best part is that since it’s receive-only, it doesn’t require a license, although [Jon] says he’s working on an encoder and transmitter too. We’re looking forward to that, but in the meantime, you might just be able to use this to capture some space memes.

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Resolution: Share Inspiration

January 4, 2025 by 4 Comments

It’s been a good 2025 so far! I just got back from Chaos Communication Congress, which is easily my favorite gigantic hacker conference of the year. (Partisan Hackaday pride puts Supercon up as my favorite moderate-sized conference, naturally.) CCC is huge. And it’s impossible to leave an event like that without your to-hack list at least doubling in length.

And then I got back home and started prepping up for the podcast, which meant reading through about a week’s worth of Hackaday in a single sitting. Which in turn adds a few more projects to the list. Thanks for that, y’all!

All of this was possible because people who do crazy nerdy things decided to share their passions with everyone. So in the spirit of the New Year, I’m going to try to document my own projects a little bit better, because if people can’t see what you’re doing, they can’t get inspired by it.

And while it’s my day job, it’s not yours, so I’d like to encourage you to point out a cool project if you see it as well. Because what’s better than inspiring other hackers to pick up the torch on a project you love?

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Button Debouncing With Smart Interrupts

January 4, 2025 by 51 Comments

Debouncing button or switch inputs on microcontrollers can be a challenging problem for those first starting to program these devices. Part of the reason for this difficulty is that real-world buttons don’t behave like the idealized textbook components we first learn about, and therefore need special consideration to operate like one would expect. There are simple ways to debounce inputs like adding a delay after a button is pressed, but for more efficient use of computer resources as well as adding some other capabilities to inputs you might want to look at this interrupt service routine (ISR) method from [Lee] aka [stockvu].

The strategy with this debounce method is not simply to use a single ISR for the button input, but to activate a second timer-based ISR at that time that runs at a certain interval which timestamps any button press and checks the amount of time the button has been active. If it’s under a certain threshold the ISR assumes it’s caused by bounce and blocks the bounce. If the timestamp ages past another longer threshold it knows the button has been released. This method allows on-the-fly adaptation between long button presses and rapid button presses and is capable of debouncing both types.

For those wanting to try this out, [stockyu] has included some example Arduino code for others to use. It’s an interesting take on a solution for a common problem, and puts very little load on the microcontroller. There are about as many ways to debounce inputs as there are microcontroller platforms, though, and you can even use a 555 timer to get this job done which frees up 100% of the microcontroller’s CPU.