Exploration in Arduino & Proxemics.
An interactive plant that senses the presence of people in its proximity and alters its behaviour as per the proximity of the people with respect to it.
Manisha Laroia, Nadine Valcin & Rajat Kumar
Kate Hartman & Nick Puckett
We started ideating about the project on Proxemics with the intent of creating an experience of delight or surprise for the people who interacted with our artefact from varying proximities. We started exploring everyday objects, notably those you would find on a desk – books, lamps, plants and how they could be activated with servos and LED lights and those activities transformed with proximity data from a distance sensor. We wanted the desired effect to defy the normal behaviour expected from the object and that it would denote some form of refusal to engage with the user, when the user came too close. In that way it was anthropomorphizing the objects and giving them a form of agency.
We explored the idea of a book, a plant or a lamp that would move in unexpected ways. The size of the objects, the limitations of the servo in terms of strength and range of motion posed some challenges. We also wanted the object to look realistic enough not to immediately draw attention to itself or look suspicious, which would help build up to the moment of surprise. We finally narrowed down on an artificial plant that in its ideal state sways at a slow pace creating a sense of its presence, but shows altered behaviour whenever people come in threshold and near proximity of it.
Don Norman in his book, The Design of Everyday Things, talks about design being concerned with how things work, how they are controlled, and the nature of the interaction between people and technology. When done well, the results are brilliant, pleasurable products. When done badly, the products are unusable, leading to great frustration and irritation. Or they might be usable, but force us to behave the way the product wishes rather than as we wish. He adds to it that experience is critical, for it determines how fondly people remember their interactions. When we interact with a product, we need to figure out how to work it. This means discovering what it does, how it works, and what operations are possible (Norman).
An essential part of this interaction is the affordance an object portrays and the feedback it returns for a usage action extended by the user. Altering the expected discoverability affordances and signifiers would result in making the experience stranger and surprising. With the rise of ubiquitous computing and more and more products around us turning into smart objects it is interesting to see how people’s behaviour will change with changed affordances and feedback from everyday objects in their environment, speculating behaviours and creating discursive experiences. Making an object not behave like it should alters the basic conceptual model of usage and creates an element of surprise in the experience. We felt that if we could alter these affordances and feedback in an everyday object based on proximity, it could add an element of surprise and open conversation for anthropomorphizing of objects.
The following art installation projects that all use Arduino boards to control a number of servos provided inspiration for our project:
Surface X by Picaroon, an installation with 35 open umbrellas that close when approached by humans. See details here.
In X Cube by Amman based design firm, Uraiqat architects consists of 4 faces of 3 m x 3 m each formed by 34 triangular mirrors (individually controlled by their own servo). All mirrors are in constant motion, perpetually changing the reflection users see of themselves. See details here.
Elisa Fabris Valenti’s Don’t Look at Me, I’m Shy is an interactive Installation where the felt flowers in a mural turn away from the visitors in the gallery when then come in close proximity. See details here.
Dunne & Raby’s Technological Dreams Series: No.1, Robots, 2007 is a series of objects that are meant to spark a discussion about how we’d like our robots to relate to us: subservient, intimate, dependent, equal? See details here.
After exploring the various options, we settled on creating a plant that would become agitated as people approached. We also wanted to add another element of surprise by having a butterfly emerge from behind the plant when people came very close. We also had LEDs that would serve as signifiers along with the movement of the plant.
We started the process by attaching a cardboard piece to the servo motor and tapping two wire stems with a plastic flower vertically on it, to test the motor activity. We wrote the code for the Arduino and used the sensor, motor, and the plant prototype to test the different motions we desired for different threshold distances.
The proxemics theory developed by anthropologist Edward Hall examines how individuals interpret spatial relationships. He defined 4 distances: intimate (0 to 0.5 m), personal (0.5 to 1 m), social (1 to 4 m) and public (4m or more). The sensors posed some difficulty in terms of getting clean data especially in the intimate and personal distance ranges. We decided on 3 ranges, combining the intimate and personal range into one less than a meter being < 1000mm, and kept the social range between 1000-3000mm and public ranges as 3000mm.
The plant has an idle state at more than 4 meters where it gently sways under yellow LEDs, an activated state where the yellow lights blink and the movement is more noticeable and an agitated state at less than a meter where its motion is rapid and jerky with red lights blinking quickly. Once we had configured the threshold distances, for which the motors could give the desired motion we moved to a refined version of the prototype.
We made a wooden box using the digital fabrication lab and purchased the elements to make the plant foliage and flowers. The plant elements were created using wire stems that were attached to a wooden base secured to the servos. The plant was built using a felt placemat (bought from Dollarama) which was cut into the desired leaf like shape attached to the wire stems. Once we confined the setup into a wooden box, like a pot holding a plant, new challenge arose in terms of space constraint. Each time the plant would move the artificial foliage would hit the side walls of the box causing an interruption in the free motion of the motor. We had to continuously trim the plant and ensure the weight was concentrated in the centre to maintain a constant torque.
The butterfly that we had wanted to integrate was attached to a different servo with a wire, but we never managed to get the desired effect as we wanted the rigging of the insect to be invisible for its appearance to elicit surprise. We therefore abandoned that idea but would like to revisit it given more time.
At this stage our circuit prototyping board, the sensors and the LEDs were not fully integrated into a single setup. The next steps was to combine all this in a single step, discretely hiding the electronics and having a single cord that powered the setup.
The final setup was designed such that the small plant box was placed within a larger plant box that housed all the wires, the circuits and the sensors. As we were to use individual LEDs the, connected LEDs were not able to fit in the plant box as they would hamper the motion of the plant and were integrated into the larger outer box with artificial foliage to hide the circuits.
Context aware computing relates to this, where: some kind of context2aware sensing method  which provides devices with knowledge about the situation around them; could infer where they are in terms of social action; and could act accordingly. The proxemic theories describe many different factors and variables that people use to perceive and adjust their spatial relationships with others and the same could be used to iterate people’s relations to devices.
Revealing Interaction Possibilities: We achieved this by giving the plant an idle state slow sway motion. In case a person entered the sensing proximity of the plant, the yellow LEDs would light up as if inviting the person.
Reacting to the presence and approach of people: As the person entered the Threshold 1 circle of proximity the yellow LEDs would blink and the plant would start rotating as if scanning its context to detect the individual who entered in its proximity radius.
From awareness to interaction: As the person continues to walk closer, curious to touch or see the plant closely, the movement of the plant would get faster. Eventually if the person entered in the Threshold 2 distance, the right LEDs would light up and the plant would have violent movement indicating a reluctance to close interactions.
Spatial visualizations of ubicomp environments: Three threshold distances were defined in the code to offer he discrete distance zones for different interaction; similar to how people create these boundaries around them through their body language and behaviour.
Challenges & Learnings
- Tuning of the sensor data was a key aspect of the project such that we were able to use it to define the proximity circles. In order to get more stable values we would let the sensor run for some time, ensuring no obstacle was in its field, until we received stable values and then connect the motor to it or else the motor would take the erratic values and produce random motions from the ones programmed.
- Another challenge was discovering the most suitable sensor positions and placement of the setup in the room with respect to the audience that would see and interact with it. It required us to keep testing in different contexts and with varying number of people in proximity.
- Apart from the challenges with the sensors, we encountered other software and hardware interfacing issues. The programming of the red and yellow LEDs (4 of each colour) presented a challenge in terms of changing from one set to the other. They were initially programmed using arrays, but getting the yellow lights to shut off once the red lights were triggered proved to be difficult and the lights had to be programmed individually in order to get the effect we desired. In a second phase, we simplified things by soldered all the lights of the same colour in parallel and ran them from one pin on the Arduino.
- The different levels of motion of the plant were achieved by a long process of trial and error. The agitated state provided an extra challenge in terms of vibrations. The rapid movements of the plant produced vibrations that would impact the box that contains it while also dislodging the lights attached to the container holding the plant.
Github Link for the Project code
We used two arduinos, one to control the servo motor with plant and the other to control the LEDs.
 Marquardt, N and S. Greenberg, Informing the Design of Proxemic Interactions. Research Report 2011100618, University of Calgary, Department of Computer Science, 2011
 Norman, Don. The Design of Everyday Things. New York: Basic Books, 2013. Print.