This project showcases how to construct a simple, playable Tic-Tac-Toe game with user input, a visual board, and opponent AI. This project was created as a final for my CS220 class at MiraCosta, and is created in Tinkercad, so components present in this project are intended to correspond to those available as part of that website's circuit design.

Game Theory and Logic Overview

The AI-Driven Tic-Tac-Toe Game is a comprehensive educational project that combines matrix-based user input with basic artificial intelligence. By simulating this classic game on a breadboard, users learn how a computer evaluates a physical state (the game board) and makes a logical decision to counter a human opponent. It’s an ideal introduction to Algorithm Design and User Interface (UI) Mapping.

Hardware Infrastructure & Control Tier

• Arduino Uno: The analytical core, running the game engine and managing the turns of both the player and the AI.
• 4x4 Keypad: The primary input device. Each button represents a specific grid coordinate on the Tic-Tac-Toe board (typically using keys 1-9).
• 16x2 Character LCD: Acts as the communication hub, displaying game messages such as "Your Turn," "Tie Game," or announcing the final winner.
• NeoPixel LEDs: Provide vibrant, color-coded visual feedback. A 3x3 grid of pixels represents the game board (e.g., Red for Player 'X' and Blue for Player 'O').
• Piezo Buzzer: Synchronizes sound effects with game actions, emitting different tones for valid moves, invalid presses, and victory fanfares.

AI Engine and Gameplay Logic

The game operates through a structured state-machine:

1. Grid Allocation: The board is represented as a 1D array of 9 integers. 0 means empty, 1 is Player, and 2 is AI.
2. Keypad Scanning: The Arduino polls the keypad row-by-row. When a button is pressed, the code maps that index to the corresponding board coordinate.
3. AI Evaluation (The Opponent): After the player's turn, the AI scans the board:
   • Priority 1 (Win): It checks if any move will complete a 3-in-a-row for itself.
   • Priority 2 (Block): It checks if the player is about to win and places an 'O' to block them.
   • Priority 3 (Strategy): If no immediate win or block is found, it picks a strategic empty spot (center or corners).
4. Victory Condition: After every move, the code checks 8 possible winning lines (3 horizontal, 3 vertical, 2 diagonal).

Educational Value in Simulation

Building this in Tinkercad highlights the power of virtual prototyping. It allows students to master the Software Logic without the risk of wiring errors. This project teaches the foundations of Conditional Logic, Array Management, and Heuristic Programming—skills directly transferable to more complex AI and game development in the professional world.