Upgraded Raster Laser Projector Goes RGB

September 18, 2024 by 7 Comments

We’ve covered a scanning laser project by Ben Make’s Everything last year, and now he’s back with a significant update. [Ben]’s latest project now offers a higher resolution and RGB lasers. A couple of previous versions of the device used the same concept of a rotating segmented mirror synchronised to a pulsed laser diode to create scanlines. When projected onto a suitable surface, the distorted, pixelated characters looked quite funky, but there was clearly room for improvement.

More scanlines and a faster horizontal pixel rate

The previous device used slightly inclined mirrors to deflect the beam into scanlines, with one mirror per scanline limiting the vertical resolution. To improve resolution, the mirrors were replaced with identically aligned mirrors of the type used in laser printers for horizontal scanning. An off-the-shelf laser galvo was used for vertical scanning, allowing faster scanning due to its small deflection angle. This setup is quicker than then usual vector galvo application, as the smaller movements require less time to complete. Once the resolution improvement was in hand, the controller upgrade to a Teensy 4 gave more processing bandwidth than the previous Arduino and a consequent massive improvement in image clarity.

Finally, monochrome displays don’t look anywhere near as good as an RGB setup. [Ben] utilised a dedicated RGB laser setup since he had trouble sourcing the appropriate dichroic mirrors to match available lasers. This used four lasers (with two red ones) and the correct dichroic mirrors to combine each laser source into a single beam path, which was then sent to the galvo. [Ben] tried to find a DAC solution fast enough to drive the lasers for a proper colour-mixing input but ended up shelving that idea for now and sticking with direct on-off control. This resulted in a palette of just seven colours, but that’s still a lot better than monochrome.

The project’s execution is excellent, and care was taken to make it operate outdoors with a battery. Even with appropriate safety measures, you don’t really want to play with high-intensity lasers around the house!

Here’s the previous version we covered, a neat DIY laser galvo using steppers, and a much older but very cool RGB vector projector.

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FLOSS Weekly Episode 801: JBang — Not Your Parents Java Anymore

September 18, 2024 by 6 Comments

This week Jonathan Bennett and Jeff Massie chat with Max Rydahl Andersen about JBang, the cross-platform tool to run Java as a system scripting language. That’s a bit harder than it sounds, particularly to take advantage of Java’s rich debugging capabilities and the ecosystem of libraries that are available. Tune in to get the details, as well as how polyglot files are instrumental to making JBang work!

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Meet The Winners Of The 2024 Tiny Games Contest

September 18, 2024 by 10 Comments

Over the years, we’ve figured out some pretty sure-fire ways to get hackers and makers motivated for contests. One of the best ways is to put arbitrary limits on different aspects of the project, such as how large it can be or how much power it can consume. Don’t believe us? Then just take a look at the entries of this year’s Tiny Games Contest.

Nearly 80 projects made it across the finish line this time, and our panel of judges have spent the last week or so going over each one to try and narrow it down to a handful of winners. We’ll start things off with the top three projects, each of which will be awarded a $150 gift certificate from our friends at DigiKey.

First: Sub-Surface Simon

While this contest saw a lot of excellent entries, we don’t think anyone is going to be surprised to see this one take the top spot. Earning an exceptionally rare perfect ten score from each of our judges, Sub-Surface Simon from [alnwlsn] grabbed onto the theme of this contest and ran like hell with it. Continue reading “Meet The Winners Of The 2024 Tiny Games Contest” →

Airline Seats Are For Dummies

September 18, 2024 by 8 Comments

You normally don’t think a lot would go into the construction of a chair. However, when that chair is attached to a commercial jet plane, there’s a lot of technology that goes into making sure they are safe. According to a recent BBC article, testing involves crash dummies and robot arms.

Admittedly, these are first-class and business-class seats. Robots do repetitive mundane tasks like opening and closing the tray table many, many times. They also shoot the seats with crash dummies aboard at up to 16 Gs of acceleration. Just to put  that into perspective, a jet pilot ejecting gets about the same amount of force. A MiG-35 pilot might experience 10 G.

We didn’t realize how big the airline seat industry is in Northern Ireland. Thompson, the company that has the lab in question, is only one of the companies in the country that builds seats. Apparently, the industry suffered from the global travel slowdown during the pandemic but is now bouncing back.

While people worry about robots taking jobs, we can’t imagine anyone wanting to spend all day returning their tray table to the upright and locked position repeatedly. We certainly don’t want to be 16 G crash dummies, either.

Crash dummies have a long history, of course. Be glad airliners don’t feature ejector seats.

Catching The BOAT: Gamma-Ray Bursts And The Brightest Of All Time

September 18, 2024 by 11 Comments

Down here at the bottom of our ocean of air, it’s easy to get complacent about the hazards our universe presents. We feel safe from the dangers of the vacuum of space, where radiation sizzles and rocks whizz around. In the same way that a catfish doesn’t much care what’s going on above the surface of his pond, so too are we content that our atmosphere will deflect, absorb, or incinerate just about anything that space throws our way.

Or will it? We all know that there are things out there in the solar system that are more than capable of wiping us out, and every day holds a non-zero chance that we’ll take the same ride the dinosaurs took 65 million years ago. But if that’s not enough to get you going, now we have to worry about gamma-ray bursts, searing blasts of energy crossing half the universe to arrive here and dump unimaginable amounts of energy on us, enough to not only be measurable by sensitive instruments in space but also to effect systems here on the ground, and in some cases, to physically alter our atmosphere.

Gamma-ray bursts are equal parts fascinating physics and terrifying science fiction. Here’s a look at the science behind them and the engineering that goes into detecting and studying them.

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Bringing The Horror Of Seaman Into The Real World

September 18, 2024 by 15 Comments

A little under 25 years ago, a particularly bizarre game was released for Sega’s Dreamcast. In actually, calling it a “game” might be something of a stretch. It was more of a pet simulator, where you need to feed and care for a virtual animal as it grows. Except rather than something like a dog or a rabbit, your pet is a talking fish with a human face that doesn’t seem to like you very much. Oh, and Leonard Nimoy is there too for some reason.

Most people in the world don’t even know this game ever existed, and frankly, their lives are all the better for it. But for those who lovingly cared for (or intentionally killed) one of these rude creatures back in the early 2000s, it’s an experience that sticks with you. Which we assume is why [Robert Prest] decided to build this incredibly faithful physical recreation of Seaman. 

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From High Level Language To Assembly

September 18, 2024 by 22 Comments

If you cut your teeth on Z-80 assembly and have dabbled in other assembly languages, you might not find much mystery in creating programs using the next best thing to machine code. However, if you have only used high level languages, assembly can be somewhat daunting. [Shikaan] has an introductory article aimed to get you started at the “hello world” level of x86-64 assembly language. The second part is already up, too, and covers control structures.

You can argue that you may not need to know assembly language these days, and we’ll admit it’s certainly not as important as it used to be. However, there are unusual cases where you really need either the performance or the small footprint, which is only possible in assembly language. What’s more, it is super useful to be able to read assembly from your high-level tools when something goes wrong.

Of course, one of the problems is that each assembly language is different. For example, knowing that the x86 assembly doesn’t completely transfer to ARM instructions. However, in most cases, the general concepts apply, and it is usually fairly easy to learn your second, third, or fourth instruction set.

We’ve had our own tutorials on this topic. You can also debate if you should learn assembly first or wait, although in this case, the audience is people who waited.