Day: February 14, 2019

Text Projector With — You Know — Lasers

February 14, 2019 by 9 Comments

We missed [iliasam’s] laser text projector when it first appeared, perhaps because the original article was in Russian. However, he recently reposted in English and it really caught our eye. You can see a short video of it in operation, below.

The projector uses raster scanning where the beam goes over each spot in a grid pattern. The design uses one laser from a cheap laser pointer and a salvaged mirror module from an old laser printer. The laser pointer diode turned out to be a bit weak, so a DVD laser was eventually put into service. A DVD motor also provides the vertical scan which is just a slight wobble of a mirror. A Blue Pill CPU provides all the smarts. You can find the code on GitHub.

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The Problem With Self-Driving Cars: The Name

February 14, 2019 by 103 Comments

In 1899, you might have been forgiven for thinking the automobile was only a rich-man’s toy. A horseless carriage was for flat garden pathways. The auto was far less reliable than a horse. This was new technology, and rich people are always into their gadgets, but the automobile is a technology that isn’t going to go anywhere. The roads are too terrible, they don’t have the range of a horse, and the world just isn’t set up for mechanized machines rolling everywhere.

This changed. It changed very quickly. By 1920, cars had taken over. Industrialized cities were no longer in the shadow of a mountain of horse manure. A highway, built specifically for automobiles, stretched from New York City to San Francisco. The age of the automobile had come.

And here we are today, in the same situation, with a technology as revolutionary as the automobile. People say self-driving cars are toys for rich people. Teslas on the road aren’t for the common man because the economy model costs fifty thousand dollars. They only work on highways anyway. The reliability just isn’t there for level-5 automation. You’ll never have a self-driving car that can drive over mountain roads in the snow, or navigate a ball bouncing into the street of a residential neighborhood chased by a child. But history proves time and time again that people are wrong. Self-driving cars are the future, and the world will be unrecognizable in thirty years. There’s only one problem: we’re not calling them the right thing. Self-driving cars should be called ‘cryptocybers’.

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The Future Of Fritzing Is Murky At Best

February 14, 2019 by 69 Comments

Fritzing is a very nice Open Source design tool for PCBs, electrical sketches, and schematics for designers and artists to move from a prototype to real hardware. Over the years, we’ve seen fantastic projects built with Fritzing. Fritzing has been the subject of books, lectures, and educational courses, and the impact of Fritzing has been huge. Open up a book on electronics from O’Reilly, and you’ll probably see a schematic or drawing created in Fritzing.

However, and there’s always a however, Fritzing is in trouble. The project is giving every appearance of having died. You can’t register on the site, you can’t update parts, the official site lacks HTTPS, the Twitter account has been inactive for 1,200 days, there have been no blog posts for a year, and the last commit to GitHub was on March 13th. There are problems, but there is hope: [Patrick Franken], one of the developers of Fritzing and the president of the PCB firm Aisler which runs the Fritzing Fab, recently gave a talk at FOSDEM concerning the future of Fritzing. (That’s a direct FTP download, so have fun).

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Creating Coherent Sound Beams, Easily

February 14, 2019 by 55 Comments

Lasers work by emitting light that is “coherent” in that it doesn’t spread out in a disorganized way like light from most sources does. This makes extremely focused beams possible that can do things like measure the distance from the Earth to the Moon. This behavior isn’t just limited to electromagnetic waves, though. [Gigs] via [CodeParade] was able to build a device that produces a tightly focused sound wave, essentially building an audio laser.

Curiously enough, the device does not emit sound in the frequency range of human hearing. It uses a set of ultrasound speakers which emit a “carrier wave” in the ultrasound frequency. However, with a relatively simple circuit a second signal in the audible frequency range is modulated on top of it, much the same way that an AM radio broadcast has a carrier wave with an amplitude modulated signal on top of it. With this device, though, the air itself acts in a nonlinear way and demodulates the signal, producing the modulated signal as audible sounds.

There are some interesting effects of using this device. First, it is extremely directional, so in order to hear sound from the device you would need to be standing directly in front of it. However, once the ultrasound beam hits a solid object, the wave is instantly demodulated and reflected from the object, making it sound like that object is making the sounds and not the device. It’s obvious that this effect is hard to experience via video, but it’s interesting enough that we’d like to have one of our own to try out. It’s not the only time that sound waves and electromagnetic waves have paired up in interesting ways, either.

Thanks to [Setvir] for the tip! Continue reading “Creating Coherent Sound Beams, Easily” →