Marie Vogelmann | Exploring Interactive Theatre

Section I: Distance Sensor HC-SR04 (Input)

After discarding several ideas for the input – e.g. infrared remote controls, magnetic wristbands, etc. – we decided to use an simple distance sensor for the interaction input of our soap.

Our choice was the HC-SR04, a distance sensor which is common and wide-spread in combination with an Arduino Uno. This kind of sensor uses ultrasonic transmitters for the range calculation, which is in favor for the usage on stage where light-based solution would have problems. It can measure objects with no direct contact in front of it within a range from 2cm up to 400cm and an angle of 15°, so in this case it also fulfills our requirements of triggering the soap. For the test setup i energized it via the 5V connection on the Arduino board.

The test setup includes:

1x HC-SR04, the distance sensor itself
2x LED (green and red)
2x 560Ω resistor
several jumper wires

So while nothing interferes in the predefined range (i set it to 4cm for testing purposes), the green LED will be on. In the moment a object will undercut this range, the green LED goes off and the red LED lights up.

IMG_20150107_172753 — Object not in range, green LEDs is on

IMG_20150107_172802 — Object in range, red LED is on

Section II – Soap Bubble Gun (Output)

As the first interaction output we asked ourselves how we can present the imagination of a soap although it doesn’t has the appearnance of it. We almost immediately thought about soap bubbles. This suggestion went through the whole concept phase and was getting elaborated quickly. We decided to use a common soap bubble gun. It was dismantled by its case and powerd by a seperate 4.5V power supply. The basic idea was to put it into the middle of of our soap and let it being triggered by the distance sensor thus soap bubbles will rise in the air when it gets activated. When activated the DC servo motor in the gun will fulfill two tasks. On the one side it will pump the soap liquid through little elastic tubes to the emmision ring of the gun. On the other side, the motor will run a little ventilator which will blow air through the mentioned ring. This is how soap bubbles are born!

For a first test setup controlling a DC motor i used:

1x DC motor, a seperate one from an Arduino Experimantation Kit
1x transistor (PN2222), has the function of an electronic switch
1x 1kΩ resistor
3x 1.5V power supply
several jumper wires

Test setup for the motor control via Arduino

2nd setup, using the soap bubble gun this time:

3th Setup, seperate DC motor with the HC-SR04:

4th Setup, soap bubble gun with the HC-SR04:

Currently we have an issue with the estimated 4.5V regularly dropping to a less amount when connecting the soap bubble gun to the circuit. This strange behaviour only occurs with the DC motor of the gun, not with the seperate one. This problem has to be investigated further and prevents the soap bubble gun from prototyp status.

Section III – LED Strand WS2801 (Output)

As the second output we want to use RGB LEDs. As the soap bubble gun they should light up the case of the soap when the distance sensor is triggered. We used the LED Strands WS2801 and LPD6803 as first hardware subjects and used the tutorial provided from Adafruit. For my case the strand has to charged mobile via battery. Since the strand needs a working voltage of 5V and we only had a 3 Cell 11.1V battery available, i had to use a simple voltage converter to reduce it to the needed amount. The strand uses 4 wires – power supply, ground, data and clock. The final aim is to let them flash in foam-like colors e.g. white and different kinds of blue.

Currently we have the issue that we can power up the strand propably with 5V but can’t control it. Still after double checking the connections and wires, basic examples e.g. flashing the strand with a single color won’t work although color examples will flash the LEDs uncontrolled. We worked with different libraries with no success. We assume that the wires don’t match as stated in the tutorial and/or are broken. We consider to work with another one from now on, so work-in-progress…

General description:

The props that were utilized in the play Michael Kohlhaas were simple props but was interactive with the characters and was used throughout the play. Some of the props that were used in the play, to show that the characters were relaxing and some when the characters were anxious or agitated. The prop that was used to show them relaxing was a shell shaped bath tub which was filled with warm water (so the actors don’t fall ill). Another prop was pieces of cartons which was used to show the audience, that the character was sending letters to ask for his horse. Another prop used to represent agitation, anxious and sometimes relaxation were cigarettes. A toy lobster was also used as a prop to enact that they were having a feast, which did not play an active role in the play.

There were also props like a small table, some chairs, cutlery and food that was used, which did not represent an important role in the play but was still used by the characters to exhibit as a meeting place. An important prop was a horse which was a main part of the play. The horse was depicted as a dead horse, which the actor brings out towards the end of the play which persuades the audience that he found the horse but it was dead.

Specific Description:

The shell shaped bath tub and the warm water was often interactive with the actors. When the characters decided to relax and talk about the horse they used the tub as the mode of relaxation and interacted with the warm water. A beach umbrella was also used as an interactive medium with the actor when he used the umbrella to cover his face to hide himself from Michael Kohlhaas, to enact that Michael Kohlhaas was talking to another person. Aside from some crucial props for example the paper castle, the ink and the letter the rest of the props were not so impact and they are traditional linear props.