Paja

by Svetlana Maras and Leyla Nasibova

Concept
After we have been introduced to the possibilities of creating interaction with electronics working with Arduino board, we decided to reconsider the thought of the object of interaction. What comes naturally is to think about visual object on computer screen with which interaction happens through designed interface or in some other way. Being inspired by some of the old means of interaction like in the puppet theatre we decided to put the accent to this mechanical aspect of work and make interaction simple. As a basic concept, we used the idea of shadow theatre (see more: http://en.wikipedia.org/wiki/Shadow_play). We wanted it to be portable, so we chose the form of a small TV-box. The main object in installation is the paper cutout figure of Charlie Chaplin.

What it does
Screen on the TV remains blank until ultrasonic sensor which is placed on the front side of the box gets the information of object (person) on a distance smaller than 2 meters. Distance corresponds to a scale that gradually switches on/off the light (and sounds) and therefore makes the image on screen visible – as you approach the TV, shadow of moving Charlie becomes stronger and stronger, and vice versa. Motor which makes Charlie move arms and legs, works without stopping.

How it works
For this installation, we used one Arduino, servo motor, very strong LED light and PING ultrasonic sensor. We programmed everything with Pure data, and used Simple Message System library.

Construction :
Led light is putt inside of the box, opposite to screen. What we needed to calculate and what determined the size of a box (installation), is the distance between the light and the object which influences the size of a shadow.
Ultrasonic sensor is in the front of a box and has to be visible in order to measure the distance correctly.
The motor rotates in both ways by assigned values. Maximum rotation is given and inside of it, movement of the motor is randomized in time and the amount of rotation which contributes to the spontaneity of Charlie’s moves. Like in a puppet theatre, he is attached by strings to a rotating tape.

Onthe inner frame, the scenery is fixed.

Pure data patch

Schematics