Procedural Barcode Synth Is As Simple As Black And White

October 10, 2020 by Matthew Carlson 3 Comments

We are no stranger to peculiar and wonderful musical instruments here at Hackaday. [James Bruton] has long been fascinated with barcode scanners as an input source for music and now has a procedural barcode-powered synth to add to his growing collection of handmade instruments. We’ve previously covered his barcode guitar, which converts a string of numbers from the PS/2 output to pitches. This meant having a large number of barcodes printed as each pitch required a separate barcode. As you can imagine, this makes for a rather unwieldy and large instrument.

Rather than looking at the textual output of the reader, [James] cracked it open and put it to the oscilloscope. Once inside, he found a good source that outputs a square wave corresponding to the black and white lines that the barcode sees. Since the barcodes [James] is using don’t have the proper start and stop codes, the barcode reader continuously scans. Normally it would stop the laser to send the text over the USB or PS/2 connection. A simple 5v to 3.3v level shifter feeds that square wave into a Teensy board, which outputs the audio.

A video showcasing a similar technique inspired [James] with this project. The creators of that video have a huge wall of different patterns of black and white lines. [James’s] next stroke of brilliance was to have a small HDMI display to generate the barcodes on the fly. A Raspberry Pi 4 reads in various buttons via GPIO and displays the resulting barcode on the screen. A quick 3d printed shell rounds out the build nicely, keeping things small and compact. All the code and CAD files are up on GitHub.

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Starshine Is A MIDI Controller For The Musically Shy

October 10, 2020 by Kristina Panos 10 Comments

What keeps people from playing music? For one thing, it’s hard. But why is it hard? In theory, it’s because theory is confusing. In practice, it’s largely because of accidentals, or notes that sound sour compared to the others because they aren’t from the same key or a complementary key.

What if there were no accidentals? Instruments like this exist, like the harmonica and the autoharp. But none of them look as fun to play as [Bardable]’s Starshine, the instrument intended to be playable by everyone. The note buttons on the outside are laid out and programmed such that [Bardable] will never play off-key.

We love the game controller form factor, which was also a functional choice. On the side that faces the player, there’s a PSP joystick and two potentiometers for adding expression with your thumbs. The twelve buttons on this side serve several functions like choosing the key and the scale type depending on the rocker switch position. A second rocker lets [Bardable] go up or down an octave on the fly. There’s also an OLED to show everything from the note being played to the positions of the potentiometers. If you want to know more, [Bardable] made a subreddit for this and other future instruments, and has a full tour video after the break.

If this beginner-friendly MIDI controller isn’t big enough for you, check out Harmonicade’s field of arcade buttons.

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Hardware Vs Software: Fight!

October 10, 2020 by Elliot Williams 41 Comments

It’s one of the great cliches in the hacker world: the hardware type and the software type. You can tell which of these two you are quite easily. When a project is actually 20% done, but you think it’s 90% done, and you say to yourself “And the rest is a simple matter of software”, you’re a hardware type. Ask anyone who has read my code, and they’ll tell you, I’m a hardware type.

Along with my blindness to the difficulties of getting the code right, I’ve also admittedly got an underappreciation of what powers lie in the dark typing arts. But I am not too proud to tip my hat when I see an awesome application of the soft stuff. Case in point: this Go board sequencer that we ran last week. An overhead webcam parses players’ moves as they put black and white stones down while playing the game of Go, and turns this into music.

The pure software type will be saying “but there’s a webcam and a Go board”. And indeed, that’s true. There are physical elements to this project that anchor it in the shared reality of the two people playing. But a hardware project this isn’t; it’s OpenCV and Max/MSP that make it work.

For comparison, look at the complexity of this similar physical sequencer. It’s got a 16 x 16 array of LEDs and switches and a CNC milled, primed, and painted surface that’s the size of a twin bed. Sawdust and hand-soldering: that’s a hardware project.

What I love about the Go sequencer is that it uses software just right. The piece is still physical. It could have just as easily been a VR world, where the two people would interact with each other only inside their goggles. But somehow that’s not quite as human as putting stones on a wooden board, sitting across from, and maybe even looking at, your opponent. The players aren’t forced to think about the software. They don’t feel like they’re playing a video game.

But at the same time, the software side of things makes all of the horrible hardware problems go away. Nobody is soldering a rat’s nest of 169 switches. There’s a webcam plugged into the USB port of a laptop. There’s a deep simplicity there.

Should you always trade out arcade buttons for OpenCV? Absolutely not! But is it worth considering the soft side when doing it in hardware is just too, well, hard? I’m open.

Homemade Gear Cutting Indexer Blends Art With Engineering

October 10, 2020 by Adam Zeloof 23 Comments

Ordinarily, when we need gears, we pop open a McMaster catalog or head to the KHK website. Some of the more adventurous may even laser cut or 3D print them. But what about machining them yourself?

[Uri Tuchman] set out to do just that. Of course, cutting your own gears isn’t any fun if you didn’t also build the machine that does the cutting, right? And let’s be honest, what’s the point of making the machine in the first place if it doesn’t double as a work of art?

[Uri’s] machine, made from brass and wood, is simple in its premise. It is placed adjacent to a gear cutter, a spinning tool that cuts the correct involute profile that constitutes a gear tooth. The gear-to-be is mounted in the center, atop a hole-filled plate called the dividing plate. The dividing plate can be rotated about its center and translated along linear stages, and a pin drops into each hole on the plate as it moves to index the location of each gear tooth and lock the machine for cutting.

The most impressive part [Uri’s] machine is that it was made almost entirely with hand tools. The most advanced piece of equipment he used in the build is a lathe, and even for those operations he hand-held the cutting tool. The result is an elegant mechanism as beautiful as it is functional — one that would look at home on a workbench in the late 19th century.

[Thanks BaldPower]

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Long Range WiFi Broadcasts Open-Source Video Conferencing

October 10, 2020 by Bryan Cockfield 18 Comments

WiFi is an ubiquitous feature of the modern landscape, but due to power restrictions on most hardware alongside the high-frequency signal it’s typically fairly limited in range. This of course leads to frustration where a WiFi signal can be seen, but the connection is unreliable or slow. While most would reach for a range extender or other hardware bridge, [tak786] was able to roll out a better solution for his workplace by using a high-gain antenna and a single-board computer which gets him an amazing kilometer-wide WiFi network.

The build uses a 10 dBi antenna from TP-Link that’s rated for outdoor use and a single-board computer which acts as a sort of router. The antenna is placed at the top of a building which certainly helps with the extreme range as well. This setup doesn’t actually broadcast an open Internet connection, though. [tak786]’s employer needed a teleconferencing solution for their building, and he also created a fully open-source video conferencing solution called trango that can run on any LAN and doesn’t require an Internet connection. The WiFi setup in this build is effectively just a bonus to make the conferencing system more effective.

[tak786] is planning on releasing a whitepaper about this build shortly, but for now you can access the source code for the video conferencing system at his GitHub page. And, before anyone jumps to conclusions, apparently this is well within FCC rules as well. Some of the comments in the linked Reddit post suggest that with an amateur radio license this system could be pushed much further, too. If you need more range than a kilometer, though, it’s not too much more difficult to do once you have all the right hardware.

Tracking Your Run Over The Long Haul

October 9, 2020 by Matthew Carlson 5 Comments

The rise of smartphone and smartwatch fitness tracking has been an absolute boon for anyone interested in tracking their runs. However, it all falls short when you need a custom feature and start getting into serious long distance running, as most smartphone batteries simply won’t last. While there are devices out there for the ultra-running enthusiast, [Ivor Hewitt] decided he wasn’t willing to pay a monthly subscription for the pricy trackers or deal with the hassle of the generic cheap versions, and decided to roll his own.

The key pieces of this project are the A9G GPS module and the RDA8955 GRS/GPRS module. They’re both incredibly small and power efficient, perfect for a project that needs to be worn on your person with a long battery life. As an added bonus, the RDA8955 also includes a SoC that’s user-programmable. After battling the lackluster documentation and tooling, [Ivor] managed to get some software running on his new system. A power bug on the A9G GPS module was potentially show stopping, but thanks to some help by folks in the community, it was diagnosed and solved.

Further additions included adding a proper charging circuit (TP4056) and a beefy 2600 mAh battery scavenged from a Sony smartphone, giving the compact system around 38 hours of active battery life. An OLED screen was added to show upcoming aid stations and overall system status, driven by a custom display library. A snazzy translucent case makes the whole device slim and easy to carry. Now at the end of a long race or training session, [Ivor] has a wealth of tracked points that has already been uploaded to his own tracking website and a fully charged phone.

Next time you’re looking for a small compact GPS tracker or cellular logger take a look at this project’s code on GitHub or the A9G and RDA8955 modules.

Thanks [Ivor] for sending this one in!

Electronic Treatment For Diabetes?

October 9, 2020 by Al Williams 24 Comments

If you ask power companies and cell phone carriers how much electromagnetic radiation affects the human body, they’ll tell you it doesn’t at any normal levels. If you ask [Calvin Carter] and some other researchers at the University of Iowa, they will tell you that it might treat diabetes. In a recent paper in Cell Metabolism, they’ve reported that exposing patients to static magnetic and electric fields led to improved insulin sensitivity in diabetic mice.

Some of the medical jargon in a paper like this one can be hard to follow, but it seems they feed mice on a bad diet — like that which many of us may eat — and exposed them to magnetic and electrical fields much higher than that of the Earth’s normal fields. After 30 days there was a 33% improvement in fasting blood glucose levels and even more for some mice with a specific cause of diabetes.

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