Prop WWII Machine Gun Courtesy Of Home Depot

May 16, 2018 by 7 Comments

There’s perhaps nothing worse than working on a project and realizing you don’t have the part you need to complete it. You look through all your stuff twice, maybe three times, on the off chance it’s hiding somewhere. Perhaps even reach out to a few nearby friends to see if they might have something you can use. Forget local stores, what you need is so specific that nobody’s going to keep it in stock. You’re stuck, and now everything has to be put on hold.

That’s precisely what happened to [Nathan Cragun] recently. He needed a Japanese Type 96 Light Machine Gun for a particular scene in the independent World War II film he’s working on, and couldn’t find one anywhere. Out of options, he ended up building a replica with parts from the hardware store. OK, so it isn’t exactly like being short a passive component or two on that new PCB you’re putting together. But while we can’t say a project of ours has ever been short a 70+ year old Japanese machine gun, we can definitely relate to the feeling.

To start his build, [Nathan] printed out a full size diagram of the Type 96 and starting placing PVC pipes on top of it to get a sense for how it would all come together. Once the basic tubular “skeleton” of the weapon was completed, he moved on to cutting the rest of the parts out of EVA foam.

The major pieces that needed to be made were the stock and receiver, but even small details like the spiral ribbing on the barrel and the sights were created to scale using pieces of foam. In a particularly nice touch, [Nathan] even made the magazine removable. If we had to guess, some Japanese soldiers will be shown reloading the weapon onscreen for added authenticity.

The important thing to remember with a filming prop like this is that it doesn’t need to look perfect, just close. It might be used in the background, or seen only for a second during a fast pan. Even in professionally produced TV and movies, many of the props are little more than carved foam. With the excellent job [Nathan] did painting and weathering this build, we have no doubt it will look completely believable in the final production.

We’re no strangers to prop builds here at Hackaday, but they are generally of the science fiction or video game variety, so a historical build is a nice change of pace.

Neural Networks Using Doom Level Creator Like It’s 1993

May 16, 2018 by 12 Comments

Readers of a certain vintage will remember the glee of building your own levels for DOOM. There was something magical about carefully crafting a level and then dialing up your friends for a death match session on the new map. Now computers scientists are getting in on that fun in a new way. Researchers from Politecnico di Milano are using artificial intelligence to create new levels for the classic DOOM shooter (PDF whitepaper).

While procedural level generation has been around for decades, recent advances in machine learning to generate game content (usually levels) are different because they don’t use a human-defined algorithm. Instead, they generate new content by using existing, human-generated levels as a model. In effect they learn from what great game designers have already done and apply those lesson to new level generation. The screenshot shown above is an example of an AI generated level and the gameplay can be seen in the video below.

The idea of an AI generating levels is simple in concept but difficult in execution. The researchers used Generative Adversarial Networks (GANs) to analyze existing DOOM maps and then generate new maps similar to the originals. GANs are a type of neural network which learns from training data and then generates similar data. They considered two types of GANs when generating new levels: one that just used the appearance of the training maps, and another that used both the appearance and metrics such as the number of rooms, perimeter length, etc. If you’d like a better understanding of GANs, [Steven Dufresne] covered it in his guide to the evolving world of neural networks.

While both networks used in this project produce good levels, the one that included other metrics resulted in higher quality levels. However, while the AI-generated levels appeared similar at a high level to human-generated levels, many of the little details that humans tend to include were omitted. This is partially due to a lack of good metrics to describe levels and AI-generated data.

Example DOOM maps generated by AI. Each row is one map, and each image is one aspect of the map (floor, height, things, and walls, from left to right)

We can only guess that these researcher’s next step is to use similar techniques to create an entire game (levels, characters, and music) via AI. After all, how hard can it be?? Joking aside, we would love to see you take this concept and run with it. We’re dying to play through some gnarly levels whipped up by the AI from Hackaday readers!

Continue reading “Neural Networks Using Doom Level Creator Like It’s 1993” →

Flood Fault Circuit Interrupter Could Save Lives

May 16, 2018 by 29 Comments

What if you didn’t have to risk your life to disconnect the power during a catastrophic storm? That’s a question many people in Houston were asking themselves as they watched water from Hurricane Harvey and other storms surge through the streets, swell in the gutters, and flood their homes.

Among these Houstonians were engineering students [Jon] and [Cyrus Jyan]. They watched as homeowners fought to safely disconnect their homes from the power grid and said, it shouldn’t have to be this way. They designed the Flood Fault Circuit Interrupter to monitor target areas and disconnect the power automatically when a credible threat is detected.

The FFCI is built on top of existing protection schemes like GFCIs and Arc Fault Circuit Interrupters. It isn’t meant to replace them, but instead tie them together and turn them off based on input from float switches.

As floodwaters rise, an EEPROM does a lookup and compare to decide if the threat is enough to shut it down. If so, an alarm signal to a shunt trip breaker can either throw the whole system to OFF, or else switch over to an alternate power source. The system is built around a standard security panel and keypad interface that supports 12 V alarm output. We particularly like the float switch enclosures that allow water to enter while keeping out debris.

The HackadayPrize2018 is Sponsored by:

Retrotechtacular: The Saturn Propulsion System

May 16, 2018 by 33 Comments

“We choose to go to the Moon in this decade and do the other things, not because they are easy, but because they are hard; because that goal will serve to organize and measure the best of our energies and skills, because that challenge is one that we are willing to accept, one we are unwilling to postpone, and one we intend to win, and the others, too”

When President Kennedy gave his famous speech in September 1962, the art of creating liquid-fueled rocket engines of any significant size was still in its relative infancy. All the rocketry and power plants of the Saturn series of rockets that would power the astronauts to the Moon were breaking entirely new ground, and such an ambitious target required significant plans to be laid. What is easy to forget from a platform of five decades of elapsed time is the scale of the task set for the NASA engineers of the early 1960s.

The video below the break is from 1962, concurrent with Kennedy’s speech, and it sets out the proposed development of the succession of rocket motors that would power the various parts of the Saturn family. We arrive at the famous F-1 engine that would carry the mighty Saturn 5 and start its passengers on their trip to the Moon at a very early stage in its development, after an introduction to liquid rocket engines from the most basic of first principles. We see rockets undergoing testing on the stand at NASA’s Huntsville, Alabama facility, along with rather superlative descriptions of their power and capabilities.

The whole production is very much in the spirit of the times, though unexpectedly it makes no mention whatsoever of the Space Race with the Soviet Union, whose own rocket program had put the first satellite and the first man into space, and which was also secretly aiming for the moon. It’s somewhat jarring to understand that the people in this video had little idea that such an ambitious program would be as successful as it became, or even that in the wake of Kennedy’s assassination the following year there would be such an effort to fulfill the aim set out in his speech to reach the moon within the decade.

The moon landings, and the events and technology that made them possible, are a subject of considerable fascination for our community. We must have covered innumerable stories about artifacts from the Apollo era in these pages, and no doubt more will continue to come our way in the future. Films like this one do not tell us quite the same story as does a real artifact, but their values lies in capturing the optimism of the time. Anything seemed possible in 1962, and those who lived through the decade were lucky enough to see this proven.

Fifty years from now, what burgeoning engineering efforts will we look back on?

Continue reading “Retrotechtacular: The Saturn Propulsion System” →

Welcome To The Internet Of Hamsters

May 16, 2018 by 8 Comments

It was only a matter of time. Everything else is getting its data logged and reported to the Internet for detailed analysis, so why should our rodents be any different? The cover story is that [Nicole Horward] hooked her pet hamster Harold up to the web because she wanted to see if he was getting as much exercise as he should. The real reason is, of course, that Harold wanted to show off to his “friends” on Hamsterbook. (Editor’s note: dead link, but take a look at the Wayback Machine.)

The hardware side of this hack is very simple, a magnetic door sensor (like the kind used in alarm systems) is used to detect each time the wheel makes a complete rotation. The sensor is hooked up to the GPIO pins of a Raspberry Pi, where it’s read by a Python script. A small LCD screen was added to give some visual feedback on Harold’s daily activity, and the whole thing was boxed up in a laser cut enclosure.

That gave [Nicole] a cute little display next to Harold’s cage, but it didn’t do much for analyzing his activity. For that, a script is used to upload the data every minute to a ThingSpeak channel via MQTT. This automatically generates attractive graphs from the raw data, making it much easier to visualize what’s happening over the long term.

Now might be a good time to brush up on your MQTT knowledge, so that your pet could be the next to join the IoT revolution.

Continue reading “Welcome To The Internet Of Hamsters” →

3D Printering: When An STL File Is Not Quite Right

May 16, 2018 by 49 Comments

STL files are everywhere. When there’s something to 3D print, it’s probably going to be an STL. Which, as long as the model is good just as it is, is no trouble at all. But sooner or later there will be a model that isn’t quite right in some way and suddenly project progress hits a snag.

When models interface with other physical things, those other components may not always be exactly as the designer expected. Being mindful about such potential inconsistencies during the design phase can help prevent problems, but it’s not always avoidable. The reason it’s a problem is because an STL file represents a solid model as a finished unit; it is not really intended to be rolled back into CAD programs for additional design changes.

STL files can be edited, but just like re-modeling a component from scratch, it can be a tricky process for those who don’t live and breathe this stuff. I’ll describe a few common issues related to STLs that can hold up getting that new project together, along with ways to deal with them. Thanks to 3D printing becoming much more commonplace, basic tools are within reach of even the least CAD-aware among us.

Continue reading “3D Printering: When An STL File Is Not Quite Right” →

IKEA Lamp With Raspberry Pi As The Smartest Bulb In The House

May 16, 2018 by 27 Comments

We love to hack IKEA products, marvel at Raspberry Pi creations, and bask in the glow of video projection. [Nord Projects] combined these favorite things of ours into Lantern, a name as minimalist as the IKEA lamp it uses. But the result is nearly magic.

The key component in this build is a compact laser-illuminated video projector whose image is always in focus. Lantern’s primary user interface is moving the lamp around to switch between different channels of information projected on different surfaces. It would be a hassle if the user had to refocus after every move, but the focus-free laser projector eliminates that friction.

A user physically changing the lamp’s orientation is detected by Lantern’s software via an accelerometer. Certain channels project an information overlay on top of a real world object. Rather than expecting its human user to perform precise alignment, Lantern gets feedback from a Raspberry Pi camera to position the overlay.

Speaking of software, Lantern as presented by [Nord Projects] is a showcase project under Google’s Android Things umbrella that we’ve mentioned before. But there is nothing tying the hardware directly to Google. Since the project is open source with information on Hackster.io and GitHub, the choice is yours. Build one with Google as they did, or write your own software to tie into a different infrastructure (MQTT?), or a standalone unit with no connectivity at all.

Continue reading “IKEA Lamp With Raspberry Pi As The Smartest Bulb In The House” →