Music Box Plays “Still Alive” Thanks To Automated Hole Puncher

September 19, 2017 by Donald Papp 20 Comments

Most projects have one or two significant aspects in which custom work or clever execution is showcased, but this Music Box Hole Punching Machine by [Josh Sheldon] and his roommate [Matt] is a delight on many levels. Not only was custom hardware made to automate punching holes in long spools of paper for feeding through a music box, but a software front end to process MIDI files means that in a way, this project is really a MIDI-to-hand-cranked-music-box converter. What a time to be alive.

The hole punch is an entirely custom-made assembly, and as [Josh] observes, making a reliable hole punch turns out to be extremely challenging. Plenty of trial and error was involved, and the project’s documentation as well as an overview video go into plenty of detail. Don’t miss the music box version of “Still Alive”, either. Both are embedded below.

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Remote Controlled Streaming Speakers

September 14, 2017 by James Hobson 16 Comments

For want of a better use of a spare Raspberry Pi Zero W and a set of LogitechZ-680 surround sound speakers, [Andre van Kammen] hacked them together to make them stream music playing from his phone.

It was stumbling across the Pi Music Box distribution that really got the ball rolling, and the purchase of a pHAT DAC laid the foundation. Cracking open the speakers’ controller case, [Kammen] was able to get 5V of power off some terminals even when the speakers were on standby — awesome! — which the Pi could use. Power and volume are controlled via the Pi’s GPIO pins with a diode to drop the voltage and prevent shorts.

Now, how to tell whether the speakers are on or off? Well, a pin on the display connector changes to 4.3V when it’s on, so wiring a 10k resistor and a diode to said pin is a hackable solution. Finishing off the wired connections, it proved possible to cram the pHAT DAC inside the controller case with the GPIO header sticking out the back to mount the Pi upon with no other external wires — double awesome!

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Reed Organ MIDI Conversion Tickles All 88 Keys

September 13, 2017 by Dan Maloney 11 Comments

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.

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Theremin In Detail

September 9, 2017 by Al Williams 4 Comments

[Keystone Science] recently posted a video about building a theremin — you know, the instrument that makes those strange whistles when you move your hands around it. The circuit is pretty simple (and borrowed) but we liked the way the video explains the theory and even dives into some of the math behind resonant frequencies.

The circuit uses two FETs for the oscillators. An LM386 amplifier (a Hackaday favorite) drives a speaker so you can use the instrument without external equipment. The initial build is on a breadboard, but the final build is on a PCB and has a case.

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Raspberry Pi AI Plays Piano

September 6, 2017 by Al Williams 7 Comments

[Zack] watched a video of [Dan Tepfer] using a computer with a MIDI keyboard to do some automatic fills when playing. He decided he wanted to do better and set out to create an AI that would learn–in real time–how to insert style-appropriate tunes in the gap between the human performance.

If you want the code, you can find it on GitHub. However, the really interesting part is the log of his experiences, successes, and failures. If you want to see the result, check out the video below where he riffs for about 30 seconds and the AI starts taking over for the melody when the performer stops.

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Teenage Engineering The Raspberry Pi

September 5, 2017 by Brian Benchoff 22 Comments

The Teenage Engineering OP-1 is a tiny, portable synthesizer loaded up with 4-track recording, a sampler, sequencers, and a quite good synthesis engine. It also fits in your pocket and looks like a calculator built in West Germany. As you would expect with a synth/sampler/sequencer, you can save sounds, tracks, and other creations to a computer. [Doug] thought if you can connect it to a laptop, you can also connect it to a Raspberry Pi. He created an all-in-one storage solution for the OP-1 using only a Pi and a small character LCD.

The process of connecting the Pi to the OP-1 is pretty simple. First, plug a USB cable into the OP-1 and the Pi. Then, place the OP-1 into Disk Mode, the synth’s method of transferring files between itself and a computer. The Pi then synchronizes, changes the color of its character display from red to green, and becomes a web server available over WiFi where all the files can be accessed.

This is the bare minimum tech required to get files into and off of the OP-1. All you need is a bit of power and a USB connection, and all the files on the OP-1 can be backed up, transferred, or replaced without any other futzing around. It’s perfect for the minimalist OP-1, and a great example of how handy a WiFi enabled Pi can be.

Thanks [Pator] for sending this one in.

Tough Pi-ano Can Take A Punch

September 4, 2017 by Brian McEvoy 14 Comments

There will be no delicate solos for [24 Hour Engineer’s] Tough Pi-ano. It was built to soak punishment from aggressive youngsters in musical therapy, specifically those on the autism spectrum and those with Down’s syndrome. The Tough Pi-ano will be bolted to a wall with heavy-duty shelf brackets so it can’t fall on anyone. The keyboard is covered in plastic and it doesn’t have any exposed metal so there will be no splinters.

[24 Hour Engineer] made a short video demonstration and if you listen closely, he has a pun in all but one sentence. We love that kind of easter egg in YouTube videos. Check it out after the break.

Inside the 48-key instrument are four Raspberry Pi Zeros where each Pi controls one octave. The redundancy ensures that a hardware failure only drops out a single octave and the kids can keep playing until replacement parts arrive. Each Pi has identical programming and a thumbwheel switch tells it which octave it will be emulating.

Programming was done with Python and Pygame and all the inputs are run to a homemade “hat” where the wires are soldered. Pygame’s sole responsibility is to monitor the GPIO and then play the appropriate note when a button is pressed, slapped, punched or sat upon.

Similar in name, the Touch Piano has no moving parts or perhaps you would rather use your Raspberry Pi in an upright piano.

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