Raspberry Pi Jukebox Hits All The Right Notes

January 22, 2019 by Tom Nardi 2 Comments

We (and by extension, you) have seen the Raspberry Pi crammed into nearly every piece of gear imaginable. Putting one inside a game console is so popular it’s bordering on a meme, and putting them into old stereos and other pieces of consumer electronics isn’t far behind. It’s always interesting to see how hackers graft the modern Raspberry Pi into the original hardware, but we’ll admit it can get a bit repetitive. So how about somebody scratch building an enclosure for their jukebox project?

[ComfortablyNumb] took the road less traveled when he created this very nice wooden Raspberry Pi enclosure in the shape of an eighth note. Stained and varnished and with a nice big touch screen in the middle to handle the controls, it’s an attractive and functional piece of home audio gear that we imagine most people would be happy to hang on their wall.

The process starts by printing out the desired shape on a piece of paper to use as guide, and then gluing together strips of wood to create the rough outline. Then the surface was thoroughly sanded to bring all of the strips of wood to the same level, and the final design was cut out. On the back of the note, [ComfortablyNumb] boxed out an area to hold the Waveshare seven-inch touch screen panel and the Raspberry Pi itself.

Having seen so many projects where the Pi is rather unceremoniously shoehorned into another device, it’s refreshing to see the results of a purpose-built enclosure. Since [ComfortablyNumb] was able to build the electronics compartment to his exact dimensions, the final result looks exceptionally clean and professional. Not a drop of hot glue to be seen. It also helps that this build only required the Pi and the display; as the device is meant to be plugged into an existing audio setup, there’s no onboard amplifier. The audiophiles out there might recoil in horror, but adding a dedicated digital to analog converter (DAC) would be easy enough to add if the stock audio on the Pi isn’t good enough for you.

The project is finished off with stain and several coats of varnish to get that deep and rich color. We don’t often find ourselves working with dead trees around these parts, but we’ve got to admit that the final product does look quite handsome. Certainly beats the LEGO cases many of our Pi projects live in.

If you’re looking for more wooden-encased Pi jukeboxes, you might enjoy this somewhat abstract magstripe-based take on the concept. Of course, we’ve also seen our fair share of actual jukeboxes receive a Raspberry infusion over the years.

[via /r/raspberry_pi]

To Make Reproduction Train Whistles, The Old Ways Are Best

January 21, 2019 by Donald Papp 9 Comments

Late last year, artist [Steve Messam]’s project “Whistle” involved 16 steam engine whistles around Newcastle that would fire at different parts of the day over three months. The goal of the project was bring back the distinctive sound of the train whistles which used to be fixture of daily life, and to do so as authentically as possible. [Steve] has shared details on the construction and testing of the whistles, which as it turns out was a far more complex task than one might expect. The installation made use of modern technology like Raspberry Pi and cellular data networks, but when it came to manufacturing the whistles themselves the tried and true ways were best: casting in brass before machining on a lathe to finish.

The original whistles are a peek into a different era. The bell type whistle has three major components: a large bell at the top, a cup at the base, and a central column through which steam is piped. These whistles were usually made by apprentices, as they required a range of engineering and manufacturing skills to produce correctly, but were not themselves a critical mechanical component.

In the original whistle shown here, pressurized steam comes out from within the bottom cup and exits through the thin gap (barely visible in the image, it’s very narrow) between the cup and the flat shelf-like section of the central column. That ring-shaped column of air is split by the lip of the bell above it, and the sound is created. When it comes to getting the right performance, everything matters. The pressure of the air, the size of the gap, the sharpness of the bell’s lip, the spacing between the bell and the cup, and the shape of the bell itself all play a role. As a result, while the basic design and operation of the whistles were well-understood, there was a lot of work to be done to reproduce whistles that not only operated reliably in all types of weather using compressed air instead of steam, but did so while still producing an authentic re-creation of the original sound. As [Steve] points out, “with any project that’s not been done before, you really can’t do too much testing.”

Embedded below is one such test. It’s slow-motion footage of what happens when the whistle fires after filling with rainwater. You may want to turn your speakers down for this one: locomotive whistles really were not known for their lack of volume.

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MIDI Association Announces MIDI 2.0 Prototyping

January 19, 2019 by Brian Benchoff 22 Comments

MIDI was introduced at the 1983 NAMM show as a means to connect various electronic instruments together. Since then, our favorite five-pin DIN has been stuffed into Radio Shack keyboards, MPCs, synths, eurorack modules, and DAWs. The standard basically hasn’t changed. Sure, we have MIDI SysEx messages to configure individual components of a MIDI setup, but at its core, MIDI hasn’t changed since it was designed as a current-loop serial protocol for 8-bit microcontrollers running at 1 MHz.

Now, ahead of the 2019 NAMM show, the MIDI Manufacturers Association (MMA) in conjunction with AMEI, Japan’s MIDI Association, are announcing MIDI 2.0. The new features include, “auto-configuration, new DAW/web integrations, extended resolution, increased expressiveness, and tighter timing”. It will retain backwards-compatibility with MIDI 1.0 devices.

The new initiative, like the release of the first MIDI spec, is a joint venture between manufacturers of musical instruments. The company lineup on this press release is as follows: Ableton/Cycling ’74, Art+Logic, Bome Software, Google, imitone, Native Instruments, Roland, ROLI, Steinberg, TouchKeys, and Yamaha.

This is not an official announcement of the MIDI 2.0 specification. This is the ‘prototyping’ phase, where manufacturers implement the MIDI 2.0 spec as envisioned, write some documentation, figure out what the new logo will look like, and design a self-certification process. Prototyping is expected to continue through 2019, when the final MIDI 2.0 spec will be released on the MIDI Association website.

As far as hardware hackers are concerned, there shouldn’t be any change to your existing MIDI implementation, provided you’re not doing anything new. It should be backwards compatible, after all. The new spec will allow for increased range in expression and ‘tighter’ timing, which might be an indication that the baud rate of MIDI (31,250 baud +/- 1%) may change. There’s some interesting things in store for the last old-school physical layer in existence, and we can’t wait to see what comes out of it.

The T-Pain Toy Is Now A Guitar Effect

January 9, 2019 by Lewin Day 8 Comments

T-Pain is rapper hailing from Florida, who made his name through creative use of the Autotune effect. Nobody quite does it like T-Pain to this day, but kids the world over got the chance with the release of the “I Am T-Pain” microphone, which puts effects on the user’s vocal to make them sound as fly as possible, batteries not included. In the spirit of musical exploration, [Simon] decided it would be interesting to turn the effect into a guitar pedal.

Initial plans were to wire the microphone to an input jack, and the speaker to an output jack, but things didn’t remain so simple. The toy comes with a line-in and a headphone jack already, but the wiring scheme is strange and one of the inputs can also act as an output under certain conditions. [Simon] took the kitchen sink approach, throwing a bunch of jacks at the circuit and putting it all in a pedal case with some knobs to twiddle some parameters.

The final result is a warbly, lo-fi vibrato when a guitar signal is fed in. It’s quite different from how the original toy sounds, but recalls us somewhat of the Anti-nautilus pedal when used in conjunction with a looper. Video after the break. Continue reading “The T-Pain Toy Is Now A Guitar Effect” →

An Easy Way To MIDI Sync Your Eurorack Build

January 3, 2019 by Lewin Day No comments

Eurorack synthesizer builds are known for a lot of things; simplicity isn’t necessarily one of them. However, not everything on a modular synthesizer build has to be inordinately complicated, a mess of wires, or difficult to understand. [little-scale] has built a neat and tidy module that might just find a place in your setup – the Chromatic Drum Gate Sync. The handy little device is based on a Teensy, and uses its USB MIDI libraries to make synchronizing hardware a snap.

The device has 12 channels, each responding to a single MIDI note. A note on message is used to set a gate high, and a note off message to set it low again. This allows very fine grained control of gates in a modular setup. The device can also output a variety of sync signals controlled by the USB MIDI clock – useful for keeping your modular rack in time with other digitally controlled synths.

It’s a build that espouses [little-scale]’s usual aesthetic – clean and tidy, with a focus on compactness. All the required details to build your own are available on Github.

We’ve seen the collision of [little-scale] and Teensy hardware before – with this rig playing 8 SEGA soundchips in unison.

Turning LEGO Blocks Into Music With OpenCV

December 30, 2018 by Donald Papp 2 Comments

We’re not sure what it is, but something about LEGO and music go together like milk and cookies when it comes to DIY musical projects. [Paul Wallace]’s Lego Music project is a sequencer that uses the colorful plastic pieces to build and control sound, but there’s a twist. The blocks aren’t snapped onto anything; the system is entirely visual. A computer running OpenCV uses a webcam to watch the arrangement of blocks, and overlays them onto a virtual grid where the positions of the pieces are used as inputs for the sequencer. The Y axis represents pitch, and the X axis represents time.

Embedded below are two videos. The first demonstrates how the music changes based on which blocks are placed, and where. The second is a view from the software’s perspective, and shows how the vision system processes the video by picking out the colored blocks, then using their positions to change different values which has an effect on the composition as a whole.

Continue reading “Turning LEGO Blocks Into Music With OpenCV” →

Adaptive Infotainment Plays Tunes To Match Your Dangerous Driving

December 29, 2018 by Bryan Cockfield 23 Comments

Part of the fun of watching action movies is imagining yourself as the main character, always going on exciting adventures and, of course, being accompanied by the perfect soundtrack to score the excitement and drama of your life. While having an orchestra follow you around might not always be practical, [P1kachu] at least figured out how to get some musical orchestration to sync up with how he drives his car, Fast-and-Furious style.

The idea is pretty straightforward: when [P1kachu] drives his car calmly and slowly, the music that the infotainment system plays is cool and reserved. But when he drops the hammer, the music changes to something more aggressive and in line with the new driving style. While first iterations of his project used the CAN bus, he moved to Japan and bought an old Subaru that doesn’t have CAN. The new project works on something similar called Subaru Select Monitor v1 (SSM1), but still gets the job done pretty well.

The hardware uses an Asus Tinkerboard and a Raspberry Pi with the 7″ screen, and a shield that can interface with CAN (and later with SSM1). The new music is selected by sensing pedal position, allowing him to more easily trigger the aggressive mode that his previous iterations did. Those were done using vehicle speed as a trigger, which proved to be ineffective at producing the desired results. Of course, there are many other things that you can do with CAN bus besides switching up the music in your car.

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