Nice PDF, But Can It Run DOOM? Yup!

January 15, 2025 by No comments

DOOM is a classic game to implement on a variety of platforms, but doompdf by [ading2210] is one we didn’t see coming. It runs a bit slow and controls are a little awkward but it does run. Entirely within a PDF file, at that.

How is this possible? PDFs are technically capable of much more than just displaying static content, and support JavaScript with their own library of functions. Adobe Acrobat implements the full spec, but modern web browsers implement at least a subset of the functionality in a sandboxed JavaScript runtime environment. Input and output are limited to things one might expect from a fancy PDF form (text input boxes, clickable buttons, things of that nature) but computation-wise, just about anything goes.

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Hacked teddybear on a desk

Turning GLaDOS Into Ted: A Tale Of A Talking Toy

January 14, 2025 by No comments

What if your old, neglected toys could come to life — with a bit of sass? That’s exactly what [Binh] achieved when he transformed his sister’s worn-out teddy bear into ‘Ted’, an interactive talking plush with a personality of its own. This project, which combines the GLaDOS Personality Core project from the Portal series with clever microcontroller tinkering, brings a whole new personality to a childhood favorite.

[Binh] started with the basics: a teddy bear already equipped with buttons and speakers, which he overhauled with an ESP32 microcontroller. The bear’s personality originated from GLaDOS, but was rewritten by [Binh] to fit a cheeky, teddy-bear tone. With a few tweaks in the Python-based fork, [Binh] created threads to handle touch-based interaction. For example, the ESP32 detects where the bear is touched and sends this input to a modified neural network, which then generates a response. The bear can, for instance, call you out for holding his paw for too long or sarcastically plead for mercy. I hear you say ‘but that bear Ted could do a lot more!’ Well — maybe, all this is just what an innocent bear with a personality should be capable of.

Instead, let us imagine future iterations featuring capacitive touch sensors or accelerometers to detect movement. The project is simple, but showcases the potential for intelligent plush toys. It might raise some questions, too.

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Repairing A Real (and Broken) Apollo-era DSKY

January 14, 2025 by No comments
Presumably the same DSKY unit installed in the simulator at MIT.

The Display/Keyboard unit – DSKY for short – is the primary way that Apollo-era astronauts communicated with the onboard computers. Not all DSKYs ended up in space, however, with the MIT hosting a simulator that features one of these units. Unfortunately the unit that ended up at [CuriousMarc]’s lab had seen better days, with the assumption being that it was the same DSKY that was installed in a photo of the old simulator. In addition to the busted EL display and two (improper) replacement keys, the insides show signs of damaged modules and possibly worse.

Without bothering to hook the unit up to the (previously restored) guidance computer, a full teardown was begun to assess the full extent of the damage. Considering that the DSKY uses latching relays for memory and two modules were ominously marked as being defective, this made for a tense wait as the unit was disassembled.

Fortunately making new DSKY-style EL displays has first been replicated in 2019, meaning that a replacement is possible. Perhaps surprisingly, the busted display still fires up in the test rig, as a testament to how robust the technology is. At the end of the teardown, the assessment is that the unit can be restored to its original condition, which will be done in the upcoming videos in this series.

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Head To Head: Servos Vs Steppers

January 14, 2025 by 3 Comments

You have a project that needs something to move. Should you use a stepper motor or a servo motor? [Matthias] has an opinion, and you can hear his thoughts in the video below. One tip we’ll take away from the video: when working with motors, shoot some high-frame-rate video and slow it down to see what’s really happening.

The initial tests looked fine at normal speed. But increasing the frame rate and decreasing the playback speed showed some very interesting things like how much each motor was overshooting. The ability to control this sort of thing is a key differentiator for these kinds of motors.

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Audio On A Shoestring: DIY Your Own Studio-Grade Mic

January 14, 2025 by 7 Comments

When it comes to DIY projects, nothing beats the thrill of crafting something that rivals expensive commercial products. In the microphone build video below, [Electronoobs] found himself inspired by DIY Perks earlier efforts. He took on the challenge of building a $20 high-quality microphone—a budget-friendly alternative to models priced at $500. The result: an engaging and educational journey that has it’s moments of triumph, it’s challenges, and of course, opportunities for improvement.

The core of the build lies in the JLI-2555 capsule, identical to those found in premium microphones. The process involves assembling a custom PCB for the amplifier, a selection of high-quality capacitors, and designing lightweight yet shielded wiring to minimize noise. [Electronoobs] also demonstrates the importance of a well-constructed metal mesh enclosure to eliminate interference, borrowing techniques like shaping mesh over a wooden template and insulating wires with ultra-thin enamel copper. While the final build does not quite reach the studio-quality level and looks of the referenced DIY Perks’ build, it is an impressive attempt to watch and learn from.

The project’s key challenge here would be achieving consistent audio quality. The microphone struggled with noise, low volume, and single-channel audio, until [Electronoobs] made smart modifications to the shielded wiring and amplification stages. Despite the hurdles, the build stands as an affordable alternative with significant potential for refinement in future iterations.

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Hackaday Europe 2025 Tickets On Sale, And CFP Extended Until Friday

January 14, 2025 by 2 Comments

We’re opening up shop for Hackaday Europe, so get your tickets now! We’ve managed to get the ticket price down a bit this year, so you can join in all the fun for $145. And if you’re reading this right now, snap up one of the $75 early bird tickets as fast as you can.

Hackaday Europe is going down again in Berlin this year, on March 15th and 16th at MotionLab. It’s going to be a day and a half of presentations, lightning talks, badge hacking, workshops, and more. This is where Hackaday hangs out in person, and it’s honestly just a great time – if your idea of a great time is trading favorite PCB design tricks, crafting crufty code, and generally trading tales of hardware derring-do.

In short, it’s the best of Hackaday, live and in person. Throughout the weekend, all the meals are catered, we’ve got live music at night, and the soldering irons will be warmed up for you. It’s going to be great!

If you’re in town on Friday the 14th, we’ll be meeting up in the evening to get together over some pre-event food and drink, sponsored by Crowd Supply. It’s a nice opportunity to break the ice, get to know the people you’re going to be spending the next 48 hours with, and just mingle without missing that great talk or wonderful workshop. Continue reading “Hackaday Europe 2025 Tickets On Sale, And CFP Extended Until Friday” →

Procedurally Generated Terrain In OpenSCAD

January 14, 2025 by 16 Comments

We’re big fans of OpenSCAD here at Hackaday — it’s free and open source software, runs on pretty much anything, and the idea of describing objects via code seems like a natural fit for producing functional parts. Rather than clicking and dragging elements on the screen, you can knock out a quick bracket or other simple component with just a few lines of code. But one of the things we don’t often get a chance to showcase is the incredible potential of generating 2D and 3D objects algorithmically.

In a recent Reddit post, [ardvarkmadman] dropped an extremely impressive snippet of OpenSCAD code that he calls TerrainGen. In fewer than fifteen lines of code, it’s able to create randomized “islands” which range from simple plateaus to craggy mountain ranges. After dropping the code in the OpenSCAD editor, you can just keep hitting F5 until you get a result that catches your eye. This seems like an excellent way to generate printable terrain elements for gaming purposes, but that’s just one possibility.

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