This is part of an on-going series of posts about littleBits projects. littleBits is available in the Adafruit store – Starter Kit,Extended Kit, Deluxe Kit, and Synth Kit.
Last week we had the pleasure of hosting Bilal Ghalib, a hacker aficionado and founder of both GEMSI (Global Entrepreneurship and Maker Space Initiative) and pocketfactory.org, at our offices in New York City. We asked Bilal to come spend time with us at littleBits and make the craziest project he could think of.
Not only did Bilal create a mind-blowing project with interesting interfaces that challenge the way we think about littleBits in combination with the physical and digital realms, his process truly showcased the power of littleBits as a prototyping tool.
See Bilal Make music with littleBits, an Excel spreadsheet, an iPad app, and light tricks!
Bilal was interested in how he could create an interface between the littleBits synth modules and his own music making tools (apps like Alchemy on the iPad) to make a more robust musical experience. His project has a number of physical and digital components that make up a multi-channel music-making machine.
“Piano Roll” Sequencer
The entire project is controlled by a “piano roll” sequencer that operates under similar principles to a player piano and is triggered by light. Bilal created a scrolling musical score by filling in dark spaces on an Excel spreadsheet and running it in between a series of 4 bright LEDs and 4 light triggers. When a dark square moves between a bright LED and a light trigger, a corresponding oscillator plays a note. This “piano roll” sequencer has four output channels and plays three notes. These sounds can be modified by adjusting the oscillators, but also by adding and mixing in other synth modules. The fourth channel, rather than producing a note, is connected to a long LED which lights up to the pattern of black squares on the scroll. The squares on this fourth channel are spaced at regular intervals and produce a pulse of light.
The light pulse put out by the long LED is read by a light trigger in a subsequent circuit that activates a drum beat in time to the “piano roll” sequencer. A normal pulse module could have been used to control the drum beat (the 2nd circuit), but with the light pulse, the drum beat corresponds with the speed of the DC motor that spins the scroll of notes, keeping the two circuits in sync with one another. The transfer of electrical signals between two isolated circuits via light is called opto-coupling. Not only is this a great way to sync up the two circuits, and it also helps the project to run more smoothly as each circuit has a separate power source. The larger and more complex a circuit gets, the more power it needs. This project also uses power adapters vs. batteries.
Conductive Servo Arms
The drum beat circuit is all based off a single pulse, but it produces three different rhythms simultaneously. This is done with a branch, a series of logic modules, and three servos. The servos are positioned on top of an iPad that has the Alchemy app open. Alchemy is a synthesizer app with a variety of sound sets and modification features (drum sounds were selected for this demo). The servo arms are dressed in conductive foam and wired to a copper pipe. When they are activated by the pulse signal, the conductive foam arms move up and down and touch certain spots on the iPad, creating different sounds of a drum rhythm. This conductive setup takes the place of a finger tap.
Logic-Based Drum Beat
This drum circuit, though controlled by one pulse, creates three different rhythms. The pulse goes into a branch where the three servos are connected. Before each servo are a series of logic modules (latches and inverters) that switch up the beats.
What’s great about this project is that you can modify the sounds and the rhythms by making physical changes (no programming is needed whatsoever). Switch up the rhythms by filling in squares on an Excel sheet, speed up the tempo by adjusting the speed of the dc motor scroll, add and subtract logic modules to mix up the drum beat, and change the quality of sound by experimenting with various synth modules.