A Pedal Powered Cinema

When the apocalypse hits and your power goes out, how are you going to keep yourself entertained? If you are lucky enough to be friends with [stopsendingmejunk], you can just hop on his pedal powered cinema and watch whatever movies you have stored on digital media.

This unit is built around an ordinary bicycle. A friction drive is used to generate the electricity via pedal power. In order to accomplish this, a custom steel stand was fabricated together in order to lift the rear wheel off the ground. A 24V 200W motor is used as the generator. [stopsendingmejunk] manufactured a custom spindle for the motor shaft. The spindle is made from a skateboard wheel. The motor is mounted in such a way that it can be lowered to rub the skateboard wheel against the bicycle wheel. This way when the rear bicycle wheel spins, it also rotates the motor. The motor can be lifted out of the way when cruising around if desired.

The power generated from the motor first runs through a regulator. This takes the variable voltage from the generator and smooths it out to a nice even power signal. This regulated power then charges two Goal Zero Sherpa 100 lithium batteries. The batteries allow for a buffer to allow the movie to continue playing while changing riders. The batteries then power the Optomo 750 projector as well as a set of speakers.

How Green Screen Worked Before Computers

If you know anything about how films are made then you have probably heard about the “green screen” before. The technique is also known as chroma key compositing, and it’s generally used to merge two images or videos together based on color hues. Usually you see an actor filmed in front of a green background. Using video editing software, the editor can then replace that specific green color with another video clip. This makes it look like the actor is in a completely different environment.

It’s no surprise that with computers, this is a very simple task. Any basic video editing software will include a chroma key function, but have you ever wondered how this was accomplished before computers made it so simple? [Tom Scott] posted a video to explain exactly that.

In the early days of film, the studio could film the actor against an entirely black background. Then, they would copy the film over and over using higher and higher contrasts until they end up with a black background, and a white silhouette of the actor. This film could be used as a matte. Working with an optical printer, the studio could then perform a double exposure to combine film of a background with the film of the actor. You can imagine that this was a much more cumbersome process than making a few mouse clicks.

For the green screen effect, studios could actually use specialized optical filters. They could apply one filter that would ignore a specific wavelength of the color green. Then they could film the actor using that filter. The resulting matte could then be combined with the footage of the actor and the background film using the optical printer. It’s very similar to the older style with the black background.

Electronic analog video has some other interesting tricks to perform the same basic effect. [Tom] explains that the analog signal contained information about the various colors that needed to be displayed on the screen. Electronic circuits were built that could watch for a specific color (green) and replace the signal with one from the background video. Studios even went so far as to record both the actor and a model simultaneously, using two cameras that were mechanically linked together to make the same movements. The signals could then be run through this special circuit and the combined image recorded all simultaneously.

There are a few other examples in the video, and the effects that [Tom] uses to describe these old techniques go a long way to help understand the concepts. It’s crazy to think of how complicated this process can be, when nowadays we can do it in minutes with the computers we already have in our homes. Continue reading “How Green Screen Worked Before Computers”

Dial is a Simple and Effective Wireless Media Controller

[Patrick] was looking for an easier way to control music and movies on his computer from across the room. There is a huge amount of remote control products that could be purchased to do this, but as a hacker [Patrick] wanted to make something himself. He calls his creation, “Dial” and it’s a simple but elegant solution to the problem.

Dial looks like a small cylindrical container that sits on a flat surface. It’s actually split into a top and bottom cylinder. The bottom acts as a base and stays stationary while the top acts as a dial and a push button. The case was designed in SOLIDWORKS and printed on a 3D printer.

The Dial runs on an Arduino Pro mini with a Bluetooth module. The original prototype used Bluetooth 2.0 and required a recharge after about a day. The latest version uses the Bluetooth low energy spec and can reportedly last several weeks on a single charge. Once the LiPo battery dies, it can be recharged easily once plugged into a USB port.

The mechanical component of the dial is actually an off-the-shelf rotary encoder. The encoder included a built-in push button to make things easier. The firmware is able to detect rotation in either direction, a button press, a double press, and a press-and-hold. This gives five different possible functions.

[Patrick] wrote two pieces of software to handle interaction with the Dial. The first is a C program to deal with the Bluetooth communication. The second is actually a set of Apple scripts to actually handle interaction between the Dial and the various media programs on his computer. This allows the user to more easily write their own scripts for whatever software they want. While this may have read like a product review, the Dial is actually open source! Continue reading “Dial is a Simple and Effective Wireless Media Controller”

Ask Hackaday: Hacking lingo fails

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Ah, CSI. What other television show could present digital forensics with such two-bit dialogue?

It’s time once again to put on your hacker hats – a red fedora, we guess – and tell us the worst hacker dialogue you’ve seen in movies or TV. We’ve seen a ton of shows and movies where writers and directors spend zero time doing any sort of research in whatever technology they’d like to show off in the story they’re trying to convey. Usually this results in lines like, “I’ll create a GUI interface using Visual Basic. See if I can track an IP address.” It’s technobabble at its best, and horribly misinformed at its worst.

We’re wondering what you, the readers of Hackaday, think are the worst examples of hacker lingo fails. Anything from, ‘Enhance!’ to the frightening real-life quote, “the Internet is not a big truck. It’s a series of tubes.”

We’ll compile your suggestions in a later post, but I’m betting something from Star Trek: Voyager will make the #1 technobabble/hacking lingo fails. There’s just too much in that show that isn’t internally consistent and doesn’t pay any heed to the laws of (fictional) physics. Warp 10, I’m looking at you. Of course there was the wonderful Habbo reference in last week’s Doctor Who, but I’m betting that was intentional as [Moffat] seems pretty up to speed on the tropes and memes of the Interwebs.

About a month ago, we asked you for your take on the worst hacking scenes ever shown on TV or film. The results made for good viewing, albeit with a surprising absence of Lawnmower Man. Now we want some dialogue to go with these horrendous hacking scenes. So, what say you, Hackaday? What are the worst hacking lingo fails you’ve seen or heard? Please be specific about what movie/TV show you’re referencing. Last time some good stuff probably slipped by because people just said a few words without context assuming we’d know exactly what they were referring to.

Ask Hackaday: What movies have the best/worst hacking scenes

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It’s time to do your best impression of [Comic Book Guy] as you make your case for trash or triumph in big screen hacking scenes. We watch a lot of movies, and it’s hard not to groan when the filmmakers cut corners by doing zero research into what using a computer actually looks like. But then once in a great while you have a team that does its due diligence and puts up a scene that makes sense to those of us in the know. So we’re wondering, what movies do you think have the best hacking scenes, and which ones are the worst offenders? Leave your opinion on the topic in the comments section.

We realize that you can come up with tons of poorly done ones, what we would really like to hear about is who did it right. We’ll get you started with a couple of examples. The image on the upper left is a scene from Tron: Legacy which we think did a fantastic job of portraying actual computer usage. You can read more about the huge amount of work that went into it in this article (via Reddit).

In the lower right is one of the most shady movies scenes that comes to mind. [Hugh Jackman] is compelled to do some ‘hacking’ by [John Travolta] in the movie Swordfish. The caption at the top of the screen is “COMPILER”, and who the heck knows what the rest of that is supposed to be?

On the hardware hacking side, it gets a little more difficult, we would LOVE some examples of hardware hacks or mods done right.

Hacker Typer lets you turn jibberish into useless code

We generated the screen full of code seen above literally by bashing a hand on the keyboard repeatedly like a monkey. You know, just like how hackers are portrayed in the movies? Hacker Typer makes you look like you know what you’re doing even though you’re too lazy to do something real. It’s a pointless website that’s none-the-less worth a few moments of your time just for the sake of amusement. You’ll be greeted with a set of options. The first lets you decide what pre-determined text will appear as you type. The rest are for page title, foreground and background colors, and number of characters that will appear with each keystroke.

The default features start off with three characters generated for each keystroke, another annoying staple of Hollywood film making. Oh well, even movies that try really hard to get things right end up getting under the skin of someone. Case in point, the Linux shell readout from Tron Legacy.

[via The Presurfer]

Science fiction, help or hindrance?

[Annalee Newitz] from io9 has written a piece about how science fiction can impact the public’s perception of scientific research. She’s covered stories ranging from Frankenstein, for showing the negatives of humans “playing god”, to The Diamond Age, for showing an inspiring use of nanotechnology.

We wonder what direct impact science fiction has had on research. Depictions of a 3D metaverse have always been compelling, but is pouring effort into half measures like Second Life a waste of time compared to serious computer interaction research?

We discussed this for a little while and concluded that whether inspiring or hindering, the very act of critically thinking about technology was beneficial. What books have inspired you in the past? Was it because they showed a better world or were they a stern warning?