Galvanic Skin Response sensor

I promised Heidi some info about making a Galvanic Skin Response sensor, like the one I used to measure skin conductivity in the Greetometer Glove to test the sweatiness of the wearer’s hands.

I used the instructions and code on this blog post:
http://cwwang.com/2008/04/13/gsr-reader/
If you don’t want to use processing, you can just do a simple Serial.println() in the Arduino serial monitor.

And I made my own electrodes out of coins, like in the example:

In the final project I soldered crimping beads onto the coins.  They need to be polished now and then.

The cool thing about skin conductivity is that it indicates more than just humidity on the skin.  If you try the example in the link above and breathe in sharply (as if surprised) while testing, you’ll see a change in the readings.  Combined with other measurements (movements, heart-rate, etc) you can start to detect stress levels.

Sewing components

I was talking with Carmen about how to attach the piezo elements to the sound gloves, and we were trying to remember the name of an embroidery technique used to attach mirrors to saris.  Well, it turns out it’s “Indian Mirror Stitch” (duh) or “Shisha Stitch”.

Here it is in one of my projects:

Google “shisha stitch” and you’ll find all sorts of instructions and variations.

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blinking LED without delay()

Andy’s step sequencer was coming along nicely until he added a delay to blink his LED to visualise the tempo.  The delay would slow down the whole main loop, meaning that all other readings (like push buttons) had to wait for the end of the delay before they were activated.

Here’s Andy’s lovely breadboard:

It just can’t be possible that Arduino has such a fundamental flaw, can it?  Well, kinda, but it turns out the problem can be solved.  In fact, the solution was right under our noses…

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who needs microcontrollers

Our concept has moved from dancer-controlling-dancer (which would be fun for dancers but maybe not suited for a performance context), to an arcade controller system. Since the arcade controller will be directly wired to the performer, we don’t need wireless communication or microcontrollers.

The joystick is four switches, and each direction controls two buzzers. It has been fun to appy programming logic to circuits… since I usually code Javascript this logic is lower level by several layers of abstraction.

One switch, two LED+vibration units:

haptic motion communication

A few links about manipulating muscles with electric pulses…

Here is the Dutch artist I mentioned who experimented on himself:
http://www.iaaa.nl/ae/artifacial/index.html

An idea of how it looked:
http://www.iaaa.nl/artex/varwin.html

His safety tips:
http://artifacial.org/safety

The device he recommends using is called a “TENS” device.  You can buy them on amazon!  This would be a great way to safely experiment with the technique throwing people off-balance.

social feedback garment

Today I talked with Heidi about the possibilities of getting fur to move or “stand on end”.  We thought it would be great to use the inherent properties of some fibres in combination with static electricity.  The thing about static electricity is that it is high voltage, so we have to be careful when combining it with wearables!

It would be great if we could achieve it in a more natural way.  Here is a webpage with a list of materials and their natural tendency to become positively or negatively charged:
http://school-for-champions.com/science/static_materials.htm

Another possibility for research is electro-magnetic fields (EMF).  Are there materials that would respond to this, apart from iron powder?

Related: http://vimeo.com/8837163
(beautiful execution, requires lots of energy)