[Adam Antok] was compelled to create this repurposed hard drive persistence of vision hack after seeing a toy of the same nature.
He used the frame, disk and motor from a drive and added LEDs under the spinning disk as the light source. The disk has 8 small holes drilled equidistant around the disk, and spiraling slightly toward the center. As the holes pass by the LEDS they are flashed by the ATtiny2313 processor to create images. To determine the position of the platters a Hall effect sensor is monitored by the 2313 to detect a magnet on the underside of the disk. There is room to display ten characters at one time. Each cursor position can scroll through the character set by rotating an encoder. For all the precision needed to coordinate the LEDs with the spinning holes the electronics and software code are amazingly simple. That’s a really nice job, [Adam]!
Persistence of vision hacks are to hackers like flames are to moths. One really nice thing about [Adam’s] project is that you can interact with it while it’s running. Check it out after the break.
For a novel take on POV, check out this slow swinging pendulum clock.
Continue reading “Disk Hack Creates Persistence of Vision”
A mysterious CD arrives in the mail with a weird handwritten code on it. What should you do? Put it in the computer and play the thing, of course!
Some might be screaming at their screens right now… this is how modern horror films start and before you know it the undead are lurking behind you waiting to strike. Seasonal thrills aside, this is turning into an involved community effort to solve the puzzle. [Johny] published the video and posted a thread on reddit.
We ran a similar augmented reality game to launch the 2014 Hackaday Prize solved by a dedicated group of hackers. It’s really hard to design puzzles that won’t be immediately solved but can eventually be solved with technology and a few mental leaps. When we come across one of these extremely clever puzzles, we take note.
This has all the hallmarks of a good time. The audio spectrogram shows hidden data embedded in the file — a technique known as steganography. There are some real contortions to make meaning from this. When you’re looking for a solution any little hit of a pattern feels like you’ve found something. But searching for the decrypted string yields a YouTube video with the same name; we wonder if they’ve tried to recover steganographic data from that source?
[Johny] mentions that this parcel was unsolicited and that people have suggested it’s a threat or something non-sensical in its entirety. We’re hoping it’s a publicity stunt and we’re all disappointed in the end, because solving the thing is the best part and publicity wouldn’t work if there was no solution.
The bright minds of the Hackaday community should be the ones who actually solve this. So get to work and let us know what you figure out!
It’s not uncommon to bitbang a protocol with a microcontroller in a pinch. I2C is frequently crunched from scratch, same with simple serial protocols, occasionally complex systems like Ethernet, and a whole host of other communication standards. But VGA gets pretty tricky because of the timing requirements, so it’s less common to bitbang. [Sven] completely threw caution to the wind. He didn’t just bitbang VGA on an Arduino, but he went one step further and configured an array of 7400 logic chips to output a VGA signal.
[Sven]’s project is in two parts. In part one, he discusses choosing a resolution and setting up the timing signal. He proceeds to output a simple(-ish) VGA signal that can be displayed on a monitor using a single gate. At that point only a red image was displayed, but getting signal lock from the monitor is a great proof of concept and [Sven] moved on to more intricate display tricks.
With the next iteration of the project [Sven] talks about adding in more circuitry to handle things like frame counting, geometry, and color. The graphics that are displayed were planned out in a simulator first, then used to design the 7400 chip configuration for that particular graphic display. It made us chuckle that [Sven] reports his monitor managed to survive this latest project!
We don’t remember seeing non-programmable integrated circuits used for VGA generation before. But bitbanging the signal on an Arduino or from an SD card slot is a great test of your ability to calculate and implement precise timings with an embedded system. Give it a try!
Continue reading “Spit Out VGA with Non-Programmable Logic Chips”
Although graphical programming languages have been around for ages, they haven’t really seen much use outside of an educational setting. One of the few counterexamples of this is Pure Data, and Max MSP, visual programming languages that make music and video development as easy as dropping a few boxes down and drawing lines between them.
A few years ago, [Thomas] and [Danny] developed a very cool Pure Data audio-visual presentation. The program they developed only generated graphics, but though clever coding they were able to generate a few audio signals from whatever video was coming out of their computer. The project is called TVestroy, and it’s one of the coolest audio-visual presentations you’ll ever see.
The entire program is presented on three large screens and nine CRT televisions. With some extremely clever code and a black box of electronics, the video becomes the audio. Check it out below.
Although this is a relatively old build, [Thomas] thought it would be a good idea to revisit the project now. He’s open sourced most of the Pure Data files, and everything can be downloaded on the project page.
Continue reading “Video from Audio and Pure Data”
Video arcades may be a thing of the past, but they’re still alive, well and were ready to play at this year’s World Maker Faire. The offerings weren’t old favorites, all were brand new games many being shown for the first time like the long-awaited VEC9. The Hall of Science building was filled with cabinets and no quarters were necessary, all were free-play.
Death By Audio Arcade was there in force with games like Particle Mace and Powerboat Italia ’88. Our personal favorite was Nothing Good Can Come of This. [Michael P. Consoli] devised a simple game: Two players in an empty room. A bullet drops from a hole in the ceiling, followed by a gun shortly thereafter. What happens next is up to the players. The simple graphics and gameplay give this title its charm. [Michael] was showing off a new stand-up cabinet for the game this year. He built the entire thing himself, working until the wee hours before load-in at Maker Faire.
[Batsly Adams], [Todd Bailey], and [Mike Dooley] teamed up to create what may be the first new vector arcade in decades. VEC9 has been teased for over 2 years. They’ve finally wrapped this game up and showed it off at the faire. VEC9 started with an old
Asteroids vector monitor found by [Batsly].
Continue reading “Arcades: Don’t Call it a Comeback”
We are surrounded by displays with “millions” of colors and hundreds of pixels per inch. With super “high fidelity” sound producing what we perceive to be realistic replicas of the real world.
Of course this is not the case, we rarely stop and think how our electronic systems have been crafted around the limitations of human perception. So to explore this issue, in this article we ask the question: “What might an alien think of human technology?”. We will assume a lifeform which senses the world around it much as we do. But has massively improved sensing abilities. In light of these abilities we will dub it the Oculako.
Let’s begin with the now mostly defunct CRT display and see what our hypothetical alien thinks of it. The video below shows a TV screen shot at 10,000 frames per second.
Continue reading “Electronics for Aliens”
The video trail effect is nothing new: it was first used in music videos like “Blame it on the boogie” from the Jackson 5 in 1978. Now, [Antonio Ospite] has put together a nice article that shows the basics of using OpenCV to create this effect in live video. He used the open source video processing package OpenCV for this, creating the effect with a short script. It can run in multiple ways, creating video trail effects, or “catch-up”trails (where the trail reverses into a final frame).
This provides an interesting example of how these video effects have become so much easier to create. The Jackson 5 video was created using a Scanimate and Quantel Paintbox system that was as big as a closet and cost hundreds of thousands of dollars. Now, you can create these effects with free software and a cheap PC. Now you just need to figure out what in our modern world looks awesome with this throwback effect.
Continue reading “Creating Video Trails In OpenCV”