Interactive Tree

Interaction Design Project [Processing + Arduino] by Harjot Bal

Context & Concept

The portrayal of a tree which alters its behaviour in response to user engagement with an external object. Creating a scene and placing the user in a visual context from the start was important in creating a strong narrative. This was accomplished by the use of background imagery which depicts a dark forest with almost dead-looking tree trunks. The addition of music, via the Minim audio library, helped heighten the sense of presence within context; a somber tune playing in the background and lasting for the entirety of the sketch conveys the isolation and out-of-touch associations made with limited human-to-nature interactions that exist today, as a result of rapid urban development. The ability to interact with nature via touch and speaking were modes of communication that were thought necessary to explore.

The Arduino Device

The device was comprised of an Arduino and Breadboard, both of which were mounted onto a compact tray, an Electret Microphone, push switch, and Force sensor. The three interactive devices were all connected to the Arduino as analog devices communicating via serial input. A BlueSmirf Module for wireless bluetooth communication was connected to the RX and TX pins on the Arduino (reversed) and to the GND and 3.3V. A 9V battery adapter made for a completely wireless experience.


Serial Communication

The Visual Color Mixer example code on the official Arduino was used to send data from multiple serial devices from the Arduino to Processing without interfering values when engaging with multiple input sensors simultaneously. The trick was basically to capture the string of data coming in from the serial ports and split each value for the respective input sensor with commas–designating parameters for value input in Processing.

Function & Interaction

  • Push Switch = Grow the tree from a simple root into a more complex structure. Unique random generation each time. Tree stops growing on switch release.
  • Mic Sensor = Conditionals placed on the mic made it sensitive to close-contact blowing which resulted in visually seeing the tree move and contort rapidly with colour change.
  • Force Sensor = Touching the force sensor resulted in what was supposed to be a physical exchange between user and tree–shown by lighting up the tree in an orange and red colour scheme, depicting warmth, life energy. The sensor was conditioned accept moderately forceful touches.

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