Interactive Storytelling Meets Technology
Inspired by the Harry Potter Sorting Hat and the game Akinator, this project aimed to create an interactive graduation cap that can guess which Dyson School staff member the user is thinking of, using only audio questions and head movements.
The Challenge
AI-like Interaction
The hat uses a decision tree and user feedback to guess the right staff member, based on a strategic questioning flowchart with over 150 nodes.
Gesture Recognition
Users nod for “yes” or shake for “no.” These gestures are detected using a gyroscope (MPU-6050), calibrated to work across different head shapes and movement styles.
Audio & Mouth Synchronisation
Each question is accompanied by synchronised mouth movement using servo motors. The mouth opens in four defined angles based on manually lip-synced video analysis.
Technical Solution
We built a dual-platform system combining mechanical motion, gesture recognition, and expressive audio playback, coordinated via serial communication between Bela and Arduino.
Dual Microcontroller Setup
Arduino handles sensors & motors, Bela manages audio & logic
Servo-Mapped Lip Sync
4 defined mouth positions (Shut, Slightly Open, Mid Open, Fully Open)
DC Motor Celebration
A spinning tassel performs a dramatic "celebration" or "strop"
Audio Synchronization
Lip-sync animation matches pre-recorded questions with precise motor control timing.
Key Components
- Arduino Uno
- Bela audio platform
- Servo motor (SG90)
- IMU sensor (MPU-6050)
- Micro Speaker + Amplifier
- Custom 3D printed parts
Development Process
Concept & Planning
Defining interaction flow, creating decision trees, and sketching mechanical designs for the animated cap.
Hardware Assembly
Integrating sensors, motors, and controllers into a wearable graduation cap structure.
Software Development
Programming sensor input handling, audio playback, and motor control synchronisation.
Testing & Refinement
Debugging communication protocols, calibrating sensors, and fine-tuning motor animations.
Project Demonstration
Watch the Cap in Action
See how the talking graduation cap interacts with users, processes their responses, and delivers its final guess with dramatic flair.
Results & Learning
This project successfully combined electronics, mechanics, and interaction design to create a playful and expressive wearable device that entertains while demonstrating advanced technical concepts.
Successful Integration
Seamless communication between Arduino and Bela platforms for real-time interaction
User Engagement
High accuracy in gesture recognition and entertaining interactive experience
Technical Innovation
Creative solution combining multiple technologies in a novel wearable format
"This project taught me the importance of interdisciplinary thinking: combining storytelling, engineering, and user experience to create truly engaging interactive systems."
