Cheap, Expandable Floor Piano Plays With Heart And Soul

Ever since we saw the movie Big, we’ve wanted a floor piano. Still do, actually. We sometimes wonder how many floor pianos that movie has sold. It’s definitely launched some builds, too, but perhaps none as robust as this acrylic and wooden beauty by [FredTSL]. If you want more technical detail, check out the project on IO.

The best part is that this piano is modular and easily expands from 1 to 8 octaves. Each octave runs on an Arduino Mega, with the first octave set up as a primary and the others as secondaries. When [FredTSL] turns it on, the primary octave sends a message to find out how many octaves are out there, and then it assigns each one a number. Whenever a note is played via conductive fabric and sensor, the program fetches the key number and octave number and sends the message back to the primary Mega, which plays the note through a MIDI music shield.

We think this looks fantastic and super fun to dance around on. Be sure to check out the build log in photos, and stick around after the break, because you’d better believe they busted out some Heart and Soul on this baby. After all, it’s pretty much mandatory at this point.

Wish you could build a floor piano but don’t have the space or woodworking skills? Here’s a smaller, wireless version that was built in 24 hours.

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Developing A Power Over Ethernet Stack Light

A common sight on factory floors, stack lights are used to indicate the status of machinery to anyone within visual range. But hackers have found out you can pick them up fairly cheap online, so we’ve started to see them used as indicators in slightly more mundane situations than they were originally intended for. [Tyler Ward] recently decided he wanted his build own network controlled stack light, and thought it would double as a great opportunity to dive into the world of Power Over Ethernet (PoE).

Now the easy way to do this would be to take the Raspberry Pi, attach the official PoE Hat to it, and toss it into a nice enclosure. Write some code that toggles the GPIO pins attached to the LEDs in the stack light, and call it a day. Would be done in an afternoon and you could be showing it off on Reddit by dinner time. But that’s not exactly what [Tyler] had in mind.

An early Arduino-based prototype.

He decided to take the scenic route and designed his own custom PCB that combines an Ethernet interface, PoE hardware, and the ESP32 into one compact unit. It’s no great secret that it only takes a few extra components to plug the ESP32 into the network rather than relying on WiFi, but it’s still not something we see done very often by hobbyists. Rarer still is seeing somebody roll their own PoE solution, but thanks to the in-depth documentation [Tyler] has provided for his circuit, that may change in the future.

On the software side [Tyler] has developed a firmware for the ESP32 that supports both Art-Net and RDM protocols, which are subsets of the larger DMX protocol. That means the controller should be compatible with existing software designed for controlling theatrical lighting systems. If you’d rather take a more direct approach, the firmware also sports a web interface and simple HTTP API to provide some additional flexibility.

While it’s exceptionally impressive, not everyone will need such a robust solution. If you just want a quick and easy way to fire up your stack light, a USB controlled relay and some Python can get you where you need to go.

2:3 Scale VT100 Terminal Gets Closer To Its Roots

When [Michael Gardi] finished his scaled down DEC VT100 replica a few months ago, he made it very clear that the project was only meant to look like a vintage terminal on the outside. A peek into the case revealed nothing more exotic than a Raspberry Pi running its default operating system, making the terminal just as well suited to emulating classic games as it was dialing into a remote system. But as any hacker knows, some projects end up developing a life of their own.

It started simply enough. The addition of an RS-232 Serial HAT to the Raspberry Pi meant that the 3D printed VT100 could actually operate as a serial terminal using software such as minicom. Then [Lars Brinkhoff] got involved. He loved the look of the printed VT100, and thought it deserved better than a generic terminal emulator. So he went ahead and started developing a custom terminal simulator for it to run.

Reliving those CRT glory days.

The idea here is that an an 8080 emulator actually runs an original VT100 firmware ROM, warts and all. It makes all the beeps and chirps you’d expect from the real hardware, and there’s even some OpenGL trickery used to mimic an old CRT display, complete with scan lines and a soft glow around characters.

Naturally the visual effects consume a fair amount of processing power, so [Lars] cautions that anything lower than the Pi 4 will likely experience slowdowns. Of course, nothing is stopping you from running the simulator on your desktop machine if you’re looking for that classic terminal experience.

Did this gorgeous recreation of the VT100 need to have a true serial interface or a simulator that recreates the unique menu system of the original? Not at all. Even without those additions, it blew us away when [Michael] first sent it in. But are we happy that these guys have put in the time to perfect this already stellar project? We think you already know the answer.

Alice Ball Steamrolled Leprosy

Leprosy is a bacterial disease that affects the skin, nerves, eyes, and mucosal surfaces of the upper respiratory tract. It is transmitted via droplets and causes skin lesions and loss of sensation in these regions. Also known as Hansen’s disease after the 19th century scientist who discovered its bacterial origin, leprosy has been around since ancient times, and those afflicted have been stigmatized and outcast for just as long. For years, people were sent to live the rest of their days in leper colonies to avoid infecting others.

The common result of injecting chaulmoogra oil. Image via Stanford University

Until Alice Ball came along, the only thing that could be done for leprosy — injecting oil from the seeds of an Eastern evergreen tree — didn’t really do all that much to help. Eastern medicine has been using oil from the chaulmoogra tree since the 1300s to treat various maladies, including leprosy.

The problem is that although it somewhat effective, chaulmoogra oil is difficult to get it into the body. Ingesting it makes most people vomit. The stuff is too sticky to be applied topically to the skin, and injecting it causes the oil to clump in abscesses that make the patients’ skin look like bubble wrap.

In 1866, the Hawaiian government passed a law to quarantine people living with leprosy on the tiny island of Moloka’i. Every so often, a ferry left for the island and delivered these people to their eventual death. Most patients don’t die of leprosy, but from secondary infection or disease. By 1915, there were 1,100 people living on Moloka’i from all over the United States, and they were running out of room. Something had to be done.

Professor Alice Ball hacked the chemistry of chaulmoogra oil and made it less viscous so it could be easily injected. As a result, it was much more effective and remained the ideal treatment until the 1940s when sulfate antibiotics were discovered. So why haven’t you heard of Alice before? She died before she could publish her work, and then it was stolen by the president of her university. Now, over a century later, Alice is starting to get the recognition she deserves.

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Printed Catamaran

If you want to send some instruments out on the lake or the ocean, you’ll want something that floats. Sure, if you need to be underwater, or if you can fly over the water there are other options, but sometimes you want to be on the surface. For stability, it is hard to beat a catamaran — a boat with two hulls that each support one side of a deck. If that sounds like the ocean sensor platform of your dreams, try printing the one from [electrosync].

The boat looks super stable and has a brushless motor propulsion system. The design purpose is to carry environmental and water quality monitoring gear. It can hold over 5 kg of payload in the hull and there’s an optional deck system, although the plans for that are not yet included in the STL files.

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Your 1958 Punch Card Machine Tested Tubes

We think of punched cards as old-fashioned, but still squarely part of the computer age. Turns out, cards were in use way before they got conscripted by computers. Jacquard looms are one famous example. The U.S. Census famously used punched cards for tabulating the census without anything we’d consider a computer. But in the 1950s, you might have had a punched card machine on your electronics workbench. The Hickok Cardmatic was a tube tester with a difference.

About Tube Testers

While you, as a Hackaday reader, might tear into a busted TV at your house and try to fix it, most people today will either scrap a bad set or pay someone to fix it. That’s fine today. TVs are cheap and rarely break, anyway. But this hasn’t always been the case.

In the “good old days” your expensive TV broke down all the time. Most of the parts were reliable, but the tubes would wear out. If you were the kind of person who would change your own oil, you’d probably look to see if you could spot a burned out tube and try replacing it. If you couldn’t spot it, you’d pull all the tubes out. If you were lucky, there was a diagram glued inside the cover that showed where they all went back. Then you took them to the drugstore.

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A Smart Light Bulb Running Doom Is A Pretty Bright Idea

A light bulb might seem like an unlikely platform for gaming, but we’re living in the future now, so anything is possible. And with enough know-how, it turns out that an RGB light bulb can indeed be modified to run Doom.

[Ed note: The project pages and video got pulled right when this went to press. Nicola received a takedown notice.  We’ll let you know more when we do. The main link has been updated to the Wayback Machine.]

That’s not to say that the Ikea TRÅDFRI light bulb is the only thing [Nicola Wrachien] needed to accomplish the hack. But the bulb, specifically this addressable GU10 RGB LEB bulb, donated the most critical component, a Silicon Labs MGM210L wireless microcontroller, with enough processing power to run vanilla Doom. Added to the microcontroller was a TFT display, a controller made from a handful of buttons and a shift register, and a few odds and ends to stitch it all together. Some more memory was needed, though, so [Nicola] used an 8 MB QSPI flash memory and a couple of neat tricks to reduce latency and improve bandwidth. There are a lot of neat tricks with this one, but the coolest thing might just be that the whole footprint of the build isn’t that much bigger than the original bulb. Check out the surprisingly smooth gameplay in the video below.

This is a nice addition to the seemingly neverending “Will it Doom?” series. We’ve seen the classic game ported to everything from a GPS to a kitchen “bump bar” computer and even to an oscilloscope.

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