Overview

EduTile is an interactive educational platform that combines physical tiles with embedded electronics to create engaging learning experiences. Designed for educators and learners, EduTile allows content customization through modular puzzle-like pieces that can be rearranged based on the topic or activity.

The system includes sensors, LEDs, and feedback mechanisms that respond to user interactions, making it ideal for teaching STEM concepts in a hands-on, exploratory way. The project integrates both hardware and software components, including a custom PCB, sensors, and a web-based interface for monitoring and control.

In this phase, I focused on fixing the system integration—ensuring all components communicate smoothly and behave reliably under real-time interaction. Below is the step-by-step documentation of what was updated, improved, or debugged in this phase.

Electronics Integration

The EduTile system is built around the integration of three custom-designed PCBs, each with a specific role and placement within the physical structure. All boards are connected using Grove headers for modular and reliable connections.

1. Main Controller PCB (Middle Base)

This PCB is placed in the middle base of the EduTile structure and serves as the central hub for the system. It includes:

  • XIAO ESP32: Acts as the main microcontroller, managing all inputs and outputs.
  • APDS9960 Sensor: Enables gesture and color detection, allowing interactive responses based on user input.
  • Grove Headers: Used to connect to the other two PCBs and external components.
  • Battery Charger Circuit: Connected to a lithium battery to provide portable power to the whole system.

2. Ring Light PCB (Lower Base)

This board is placed in the lower base and holds a circular array of Flora RGB LEDs. It includes Grove connectors for easy integration with the main controller. The ring light is used for visual feedback and signaling user interactions or learning states.

3. Output PCB (Puzzle Piece – Upper Section)

The final board is embedded in one of the movable puzzle pieces. It contains:

  • Vibration Motor: For haptic feedback when an interaction is triggered.
  • Flora RGB LED: Additional visual cue for specific events or answers.
  • OLED Screen: Displays text or icons related to the learning activity.
  • Grove Headers: Allow it to communicate with the main board when connected.

This modular electronic architecture allows for distributed functionality while keeping the system easy to maintain and reconfigure.

3D Model and Enclosure Design

The physical structure of EduTile was designed with precision to ensure proper fit, accessibility, and functionality for all electronic components. Initially, the assembly relied on threaded connections between the puzzle piece and the two base layers. However, in the final version, I made several key improvements to enhance usability and performance.

Magnetic Assembly

I replaced the threaded connections with embedded magnets to allow quick and secure assembly and disassembly. This made the structure easier to open for debugging, charging, or updating the electronics while maintaining firm alignment between layers.

Pass-throughs for Grove Connectors

To accommodate the Grove cables connecting the three PCBs, I added dedicated holes and channels in the model. These ensure that the wires pass through each layer smoothly without bending or pressure that could damage the connectors.

Lower Base – Ring Light and Sensor Alignment

The lower base features a press-fit cavity designed for the ring light PCB. It surrounds an opening for the APDS9960 sensor, which is positioned at the very center of the system. This central placement was chosen carefully to ensure accurate gesture and color readings. The distance from the sensor to the surface and the amount of light from the ring were calibrated to support optimal sensor performance under various conditions.

Middle Base – Controller and Routing

The middle base securely holds the main controller PCB in a press-fit slot. It includes holes that guide wires to the upper and lower PCBs while maintaining a clean internal layout. The middle base also allows the sensor to face through the lower base unobstructed, preserving direct line-of-sight for accurate readings.

Upper Piece – Output Placement and Expression

The top puzzle piece houses the output PCB, and its design emphasizes both function and aesthetics:

  • The OLED screen is centered on the piece, resembling a “face” or central display for the user, making content easy to see and feel purposeful.
  • The Flora RGB LED is positioned behind translucent material where the “eyes” of the piece would be, adding expression and emotional feedback through light.
  • The vibration motor is placed along the edge of the piece, ensuring the haptic feedback is easily felt when holding it, especially during interaction or when a correct answer is triggered.

These design choices ensure that each output feels like a natural part of the puzzle piece, enhancing the overall interactive experience while maintaining a friendly and intuitive look.

Assembly and User Experience

The final structure of EduTile is designed to be modular, interactive, and user-friendly—both in how it’s assembled and how it feels during use. All the components come together like a carefully designed puzzle, with each part playing a specific role in functionality and engagement.

Laser-Cut Puzzle Pieces

The top layer of EduTile features laser-cut jigsaw puzzle pieces made from wood or acrylic. Each piece is cut with precise dimensions to fit perfectly onto the main 3D-printed structure of the piece. This alignment ensures a snug fit, while still allowing easy removal or rearrangement during learning activities. The interlocking design reinforces the idea of learning "piece by piece."

Thoughtful Ergonomics

The piece that houses the output PCB—the one users interact with directly—was modeled with user experience in mind. The shape, size, and curves of the piece make it easy and comfortable to hold. The weight distribution was considered to ensure it feels balanced in hand.

Cutouts and placements of elements like the OLED screen, RGB LED eyes, and vibration motor were positioned to make the interaction feel natural and intuitive. For example:

  • The OLED screen is visible at a glance when holding the piece upright.
  • The vibration motor is positioned so the haptic feedback can be felt clearly through the user’s fingers.
  • The smooth finish and rounded edges make it suitable for children or educators to use comfortably during activities.

Stacked Layer Design

EduTile's structure is built from multiple layers: the upper puzzle piece, the middle controller base, and the lower light ring base. These layers are aligned and stacked with magnetic and press-fit joints, allowing quick assembly and secure positioning.

Each layer is precisely modeled so wires pass cleanly through without tangling, and no internal components are compressed or strained. This careful consideration results in a polished product that is reliable and easy to maintain.