Harmonic Dialogues

An Interactive Installation

Autumn’s Veil is an immersive, interactive installation that merges art and technology to reflect the beauty and transience of seasonal change. The project explores the inevitability of life’s cycles and invites viewers to nurture their inner light through both life’s highs and challenges. Through an integration of motion detection, lighting, and responsive materials, Autumn’s Veil immerses viewers in the changing nature of the seasons, guided by their own movements.

Group members: JC Zhang, Mahnoor Hasan, Erinma Arki & Peter Oke

Overview

Harmonic Dialogues is an interactive installation that transforms vocal interactions into visual
art. Designed with a microphone and motion sensor, it responds to the voices and
movements of two people, activating servos that move the pens across paper positioned
between them. Each participant's input generates colorful scribbles, with each pen assigned
a different color to distinguish their contributions. The result is a collaborative, ever-evolving
artwork that visualizes the rhythm, energy, and interplay of conversation.

Installation Experience

Participants engage in a collaborative drawing experience where their voices and
movements influence the artwork in real time. The system fosters interaction by ensuring
both participants contribute while introducing an element of disruption when one voice
dominates, reinforcing the idea of balance in the conversation. The resulting piece is an
evolving visualization of their interaction, capturing the rhythm, energy, and interplay of
human communication through technology.

System Diagram

Inputs and Outputs

1. Input Stage
Each participant interacts with Harmonic Dialogues using voice and movement, which are
captured through:
● Microphone breakouts (x2) – Capture vocal inputs and convert their volumes into
analog signals.
● Motion Sensors (x2) – Detects participants’ movements near their station, sending
out digital signals
● Potentiometers (x2) – Set up the minimum and maximum thresholds for volume
inputs.

2. Signal Processing & Decision Making
● Comparators (x2) – compare the volumes picked up by the microphones and
determine whether the inputs surpass the predefined thresholds, sending out digital
signals: High or Low.
● AND Gate Logic: This ensures that both voice and movement are present before
activating the servo motors to move the corresponding pens.
● NAND Gate Logic – with a pull-up resistor, works as a NOT, reversing the digital
signal from the motion sensors.
● Arduino Boards (x2) – Act as the central processors, interpreting inputs, managing
part of the logic operations, and controlling the servos’ angles accordingly.

3. Output & Visualization
● Servo Motors (x2) – Move the colored pens, translating participant interactions into
scribbled patterns on paper.
● Motor/Continuous Servo - Moves the paper when either of the pen is drawing on
the paper
● LED Indicators (3):
○ Yellow LED: canEcho – Stays ON when no movement is detected.
○ Green LED: isDrawing – Activates when motion and voice input exceed the
minimum threshold.
○ Red LED: isBlocked – Activates when input surpasses the maximum
threshold.
● Drawing Paper on a Roll Holder – Provides a continuous surface for capturing the
visual output.
● Colored Pens (x2) – Distinguish each participant’s contributions, creating a layered
and interactive visual representation of their conversation.

My Role: Creative and Visual Coordinator

My central role in the "Harmonic Dialogues" project was to serve as the bridge between the technical engineering of the system and the conceptual promise of the artwork. While my teammates skillfully managed the circuitry, code, and structural design, my mission was to define the aesthetic language and ensure that every mechanical function served as an accurate, compelling visual metaphor for human conversation.

I was responsible for selecting the physical tools of expression: the Colored Pens. Choosing the specific type of pen and the color pairing was not arbitrary; the colors needed to be distinct enough to differentiate the contributions of the two participants, yet harmonious enough to blend into a unified, collaborative final piece. My goal was to ensure the "mark-making" quality—the texture and stroke produced by the servos—aligned with our conceptual inspiration, which favored imperfect and nuanced scribbles over clinical precision. This defined the raw, expressive quality of the finished scrolls.

Finally, I oversaw the Overall Experience and the integrity of the installation. I ensured the LED Indicators were placed and bright enough to provide intuitive feedback without becoming distracting. Every element, from the spacing of the chairs to the quality of the paper roll, was managed to ensure the physical environment was conducive to the intimate, reflective dialogue we aimed to visualize. My ultimate responsibility was ensuring that the complex logic of the system resulted in an eloquent, sensitive, and emotionally resonant visualization of two people interacting.

Iterative Process

Prototyping

The prototyping phase involved simultaneously developing the physical architecture and the electronic framework. The physical prototype—the Frame Building stage—resulted in a custom wooden structure designed to serve several mechanical purposes. This frame housed the two mirrored electronic stations and, more critically, provided mounting points for the two servo motors and established the paper roll holder mechanism.

The initial build was crucial for determining the optimal spacing between participants, the height and reach of the drawing pens, and the feasibility of the continuous paper feed, all of which directly impacted the intended user experience. Simultaneously, the electronic design was prototyped on a breadboard, using two Arduino boards to manage the complex system of inputs, logic gates, and outputs. This early electronic setup allowed the team to immediately begin testing the integration of sensors and actuators before committing to the final, hard-wired circuit.

Testing

The core of the development process lies in the systematic Circuit testing and general performance Testing. Given that the installation’s behavior is governed by precise flowchart logic—requiring the simultaneous activation of voice and motion inputs via an AND gate—verification was paramount.

First, Circuit Testing confirmed the integrity of the individual components and the signal flow. This involved testing the microphone breakouts, the motion sensors, and the potentiometers to ensure they accurately captured inputs and converted them into reliable signals for the comparators. A critical technical test was the functioning of the AND Gate Logic, which required verifying that the drawing action (pen movement) only initiated when both the motion sensor was tripped and the vocal volume surpassed the minimum threshold. The documentation even notes a minor material constraint—using a substitute wire color—a testament to the practical, real-time adjustments common during hardware testing.

Second, Behavioral Testing focused on the overall system performance and the resulting artwork. The team tested the three LED indicators (Yellow, Green, Red) to confirm they accurately reflected the system's state (waiting for motion, drawing, or being blocked). Furthermore, extensive testing was dedicated to the interaction loop:

Threshold Validation: Ensuring the potentiometers accurately set the "isDrawing" threshold (Green LED) and the "isBlocked" threshold (Red LED), which signifies dominance and introduces the intended disruption.

Actuator Precision: Verifying that the servo motors moved the pens within the intended half-range or full-range motion according to the input level.

Paper Feed Consistency: Testing the continuous servo to ensure the paper advanced smoothly and consistently during the drawing process.

Refinement

Refinement was an ongoing process, driven by the findings from the testing stages, to align the technical reality with the conceptual goal of visualizing dialogue. The Overall Experience aimed to foster balance while allowing for disruption.
One major area of refinement would have been the tuning of the Potentiometers and their linked Comparators. If the minimum voice threshold was too low, the pen would draw constantly; if it was too high, the system would feel unresponsive. Similarly, the maximum threshold, which triggers the isBlocked state (Red LED), needed careful calibration to ensure the disruption felt appropriate to a conversational imbalance, rather than arbitrary noise.

Circuit Diagram

Final Design

Project Video

Lessons learned

Looking back at the development of "Harmonic Dialogues," several key insights emerged that are valuable for any designer working on tangible, interactive systems:

Calibration is Interaction Design: The potentiometers and comparators were the core design parameters of the user experience. The act of tuning the minimum and maximum input thresholds demonstrated that achieving meaningful interaction in a physical computing project depends entirely on fine-tuning the analog inputs to match a qualitative human concept.

Low-Fidelity Feedback is High-Impact: The simplicity of the three-color LED indicator system (Yellow, Green, Red) proved remarkably effective. Rather than requiring a screen or complex instructions, these lights provided immediate, non-intrusive feedback on the system's state (waiting, drawing, or blocking). This confirmed the power of using the most basic physical cues to guide complex user behavior, achieving "intuitive feedback without becoming distracting."

Embracing Constraint Enhances Meaning: The final aesthetic of the artwork—the scribbles—was inherently limited by the mechanics of the servo motors. Instead of fighting for perfect geometric output, we leaned into the servos’ slightly jerky, imperfect motion. This constraint became a feature, reinforcing the conceptual link between "imperfect human expression" and the art itself. For future projects, I learned to identify which technical limitations can be celebrated as expressive qualities rather than mitigated as errors.

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