Hackaday editors Mike Szczys and Elliot Williams review a great week in the hacking world. There’s an incredible 4k projector build that started from a broken cellphone, a hand-cranked player (MIDI) piano, and a woeful story of clipboard vulnerabilities found in numerous browsers and browser-based apps. Plus you’ll love the field-ready solder splice that works like a strike-on box match (reminiscent of using thermite to weld railroad rail) and we spend some time marveling at the problem of finding power cuts on massive grid systems.
Take a look at the links below if you want to follow along, and as always, tell us what you think about this episode in the comments!
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Continue reading “Hackaday Podcast 073: Betrayal By Clipboard, Scratching 4K, Flaming Solder Joints, And Electric Paper”
What did you do in high school? Chances are it wasn’t anywhere near as cool as turning a reed organ into a MIDI device. And even if you managed to pull something like that off, did you do it by mechanically controlling all 88 keys? Didn’t think so.
A reed organ is a keyboard instrument that channels moving air over sets of tuned brass reeds to produce notes. Most are fairly complex affairs with multiple keyboards and extra controls, but the one that [Willem Hillier] scored for free looks almost the same as a piano. Even with the free instrument [Willem] is about $500 into this project. Almost half of the budget went to the solenoids and driver MOSFETs — there’s a solenoid for each key, after all. And each one required minor surgery to reduce the clicking and clacking sounds that don’t exactly contribute to the musical experience. [Willem] designed custom driver boards for the MOSFETs with 16 channels per board, and added in a couple of power supplies to feed all those hungry solenoids and the three Arduinos needed to run the show. The video below shows the organ being stress-tested with the peppy “Flight of the Bumblebee”; there’s nothing wrong with a little showing off.
[Willem]’s build adds yet another instrument to the MIDI fold. We’ve covered plenty before, from accordions to harmonicas and even a really annoying siren.
Continue reading “Reed Organ MIDI Conversion Tickles All 88 Keys”
Piano rolls are the world’s longest-lasting recording medium, and its first digital one. They were mass-produced from 1896 to 2008, and you can still get some made today, although they’re a specialty item. The technology behind them, both on the player and the recorder side, is simply wonderful.
[lwalkera] sent us in this marvelous video (embedded below) that provides a late-80s peek inside the works of QRS Records, and the presenter seems to be loving every minute of it.
Player pianos are cool enough, with their “draw bar” pulling air through the holes in the paper roll as it goes by, and pneumatically activating the keys. But did you ever think of how the rolls are made?
Continue reading “Retrotechtacular: Piano Rolls, Made By Apple ][“
For all the destruction and human misery unleashed during World War II, it was also a time of incredible creativity and ingenuity. In America, it was a time when everyone wanted to pitch in. Young men and women enlisted and were shipped overseas, and those left behind kept the factories running full tilt. Even Hollywood went to war, with its steady output of films that gave people a little glamour and provided an escape from the horror and loss of the war. Hollywood stars lined up to entertain troops and raise money for the war effort, and many joined up and fought too.
But one Hollywood star made an unconventional contribution to the war effort, and in the process proved that beauty and brains are not always mutually exclusive. This is the story of Hedy Lamarr, movie star and inventor.
“The Most Beautiful Woman in the World”
By the time she was 23 in 1937, Hedwig Eva Maria Kiesler was a genuine film star in her native Austria. She was also trapped in an unhappy marriage to a rich and powerful Austrian munitions magnate, Fritz Mandl. Hedy was miserable as a trophy wife, adorning the dining room as her husband entertained rich and powerful guests – including Mussolini and Hitler – over long dinners in one of his mansions. They dismissed her; clearly a woman so beautiful could have nothing else to offer, an empty head perched on a graceful neck. But she was far from stupid, and while her husband discussed business with the men who were building the Axis arsenal, Hedy listened and learned.
Continue reading “Citizen Scientist: Hedy Lamarr”
[Ramon] was always fascinated with pianos, and when he came across a few player piano rolls in an antique shop, a small kernel of a project idea was formed. He wondered if anyone had ever tried to convert a player piano into a full MIDI instrument, with a computer tickling the ivories with a few commands. This led to one of the best builds we’ve ever seen: a player piano connected to a computer.
[Ramon] found an old piano in Craigslist for a few hundred dollars, and once it made its way into the workshop the teardown began. Player pianos work via a vacuum, where air is sucked through a few pin points in a piano roll with a bellows. A series of pipes leading to each key translate these small holes into notes. Replicating this system for a MIDI device would be impossible, but there are a few companies that make electronic adapters for player pianos. All [Ramon] would have to do is replicate that.
The lead pipes were torn out and replaced with 88 separate solenoid valves. These valves are controlled via a shift register, and the shift registers controlled by an ATMega. There’s an astonishing amount of electronic and mechanical work invested in this build, and the finished product shows that.
As if turning an ancient player piano into something that can understand and play MIDI music wasn’t enough, [Ramon] decided to add a few visuals to the mix. He found a display with a ratio of 16:4.5 – yes, half as tall as 16:9 – and turned the front of the piano into a giant display. The ten different styles of visualization were whipped up in Processing.
The piano has so far been shown at an interactive art exhibit in Oakland, and hopefully it’ll make it to one of the Maker Faires next year. There are also plans to have this piano output MIDI with a key scanner underneath all the keys. Very impressive work.
Continue reading “Making A Player Piano Talk MIDI”
A while back, [Jacob] played around with a player piano. After feeding a roll into the machine and trying to figure out how a fifty year old machine using hundred year old technology can replicate a skilled pianist, he decided to take a crack at decoding piano rolls for himself. He came up with a clever way of doing it over Christmas break, using a camera and a few bits of OpenCV.
The old-school mechanics of a player piano use a bellows and valve system to suck air through dozens of holes, making the action hit a string whenever a hole is present in the piano roll. To bring this mechanism into the modern age, [Jacob] pointed a video camera at the active part of the piano roll and used OpenCV to translate holes in a piece of paper to a MIDI file.
The synthesized version sounds just as good as the original paper scroll-based version, as seen in the video after the break. There are a few sync issues in the video and the resulting MIDI file isn’t in the right key, but that’s easily fixed by anyone willing to replicate this project.
Continue reading “Reading Piano Rolls Without A Player Piano”
What do you do with 100 player piano rolls but no player piano? You come up with a way to digitize the information for MIDI playback. The rolls have 90 columns worth of holes, 88 for the keys and two more for pedals. Voids in the paper cause a note or pedal to be played, so an optical sensor can be used to transform the analog data into digital information. Simple enough, you’ll just need 90 sensors. But this brings up quite an alignment issue. The solution is to use fiber optic cable to position the IR light source in a hand-made 0.2″ spaced jig. At least the spacing meshes nicely with standard 0.1″ protoboard, which is what was used for mounting the sensors.