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Category Archives: DIY

For Science Day 2012 at UL, we decided to build a fun controller and sound synthesis demo. Over the past few years, we’ve had a number of postgraduate students exploring for example Galvanic Skin Response for artistic expression. It was slightly surprising to see the hype when Makey Makey launched earlier in 2012. I was puzzled that they didn’t seem to be aware of the work by for example Erkki Kurenniemi and Ralph Lundsten in the late 1960s and early 1970s. Kurenniemi’s DIMI-S is Lundsten’s Love Machine.
We were inspired by the original work by Kurenniemi and Lundsten and we designed and built a 16 channel analogue resistance multiplexer. The circuit uses four inexpensive CMOS chips (CD4051, 8-channel mux) and a couple of transistors (connected as a current mirror), connected to an Arduino and then to a laptop running Pure Data (PD). The Arduino controls what two pins that are active at any given time, rapidly scanning the whole matrix of possibilities (there are 240 possible connections, with 16 channels).
LoveMachine++ interface circuit
We then designed a sound synthesis system in Pure Data (PD) with both a spectral synthesizer, taking the parameters from the resistance matrix and doing a reverse Fast Fourier Transform, and a sequencer, where the mixing and filtering is controlled by the resistance matrix.
LoveMachine++ demo setup
We had to explain to the first few students that they had to touch at least two fruits or vegetables to get sound. After about an hour, word was spreading and experimentation flourished, with several students holding on to vegetables, shaking hands, touching foreheads, etc.

A short video clip from today’s demo.

Schematic diagram

LoveMachine++ interface Schematic Diagram

Bill of Materials

Name Value/Type Description Quantity
D1-3 1N4148 Diode 3
IC1-4 CD4051 8 channel analogue multiplexer 4
Q1-2 BC556 PNP transistor 2
R1 560K Resistor, 0.25W 1
R2 220K Resistor, 0.25W 1
R3 47K Resistor, 0.25W 1

Source code

Arduino code

PD patch

[note: I cobbled together a simple communication protocol in the code and patch above. Basically, an ASCII-based fixed packet length with a terminator character, which makes it easy to see and debug]

——

Some background on Kurenniemi’s work:

Mikko Ojanen, Jari Suominen, Titti Kallio, Kai Lassfolk (2007) Design Principles and User Interfaces of Erkki Kurenniemi’s Electronic Musical Instruments of the 1960’s and 1970’s, Proceedings of the International Conference on New Interfaces for Musical Expression, pp. 88–93.

With the emergence of wonderful audio apps such as Audioboo, it has become a challenge to record outdoors without the rumbling from wind hitting the microphone.
If you get some nice fluffy textile (see my note DIY Wind-jammer for Zoom H1), you can use a similar, but even simpler approach.
Cut textile
Cut a piece of the fluffy textile about 2 centimeters wider than your phone and about twice the length of the “base” of the phone.
Fold and stitch
Fold the textile with the fluffy side in and sew/stitch along the short sides.

turn inside-out, attach to phone
Turn the textile inside-out (so it gets the fluffy side out!)
Put it on your phone and record.

Happy Recording!

(and similar audio recorders)

For casual professional recording of everyday sounds, ranging from nature to interviews, the Zoom H1 is a very convenient and inexpensive device. With outdoor recording, wind is almost always present in places like Ireland. If you use a H1 as it is, your recordings will rumble with every puff of wind and destroy your recording.
To remedy this, I initially bought a simple foam windshield and this was sufficient on calm days. But for the normal gusts of westerly winds we get in Ireland, the design had to be improved. Rycote are making Mini Windjammers that cost around £STG25.  As I know how windjammers work, I found the cost excessive and the Rycote design perhaps not the optimal solution.
Fluffy textile
I bought some nice fluffy/hairy textile in a local shop (Hickey’s). The criteria for the material was that the base material should be as transparent as possible and the outer coating as hairy as possible. As this was shortly after St Patrick’s day, I bought 2 meters of a green fluffy material for 5 euro (which is enough for perhaps 20 windjammers).
Wire cage
Next, I made a small cage from brass-wire, to contain the H1. You can use any kind of semi-rigid wire for this.

After shaping the wire-cage, I folded some fluffy textile around it with the inside out and marked where to cut the textile.

Fluffy textile sticthed together, and Velcro

I sewed the front of the textile in a curve to fit the front of the wire-cage, and along the bottom I stitched on some Velcro, which makes it easy to put the textile on on the cage and to get, for example, a headphone cable through.

Elastic cage
Finally, I used some elastic band to hang the Zoom H1 in the cage, to prevent handling noise and other unwanted vibrations to be picked up, and inserted the cage with the H1 into the green fluffy tube. Zip up the Velcro and you’re ready for recording.

Zoom H1 and Windjammer

Finished H1 Windjammer

Happy Recording!