🕹️ Connect 4 AI: Master Edition

A high-performance Connect 4 implementation for ESP32-C3 and 8x8 WS2812B matrices. Features dynamic difficulty scaling, "humanized" AI movement, and a mobile-friendly web administration portal.

🛠 Hardware Configuration

🔌 Pin Mapping (Lolin C3 Mini)

Component	ESP32-C3 Pin	Function
NeoPixel Matrix	`GPIO 4`	Data Input (DIN)
Rotary Encoder A	`GPIO 0`	Directional CLK
Rotary Encoder B	`GPIO 1`	Directional DT
Encoder Button	`GPIO 2`	Selection (SW)

📐 Physical Dimensions

Designed for standard 8x8 matrix modules (approx. 65mm x 67mm).

Top Row (0): Interaction and AI decision visualization.
Game Board: Standard 7 \times 6 grid.
UI Borders: Fixed blue frame for visibility.

🧠 Advanced AI Features

1. Progressive Difficulty (Evolution Mode)

The AI search depth (Ply) increases as the board fills. This ensures the AI is fast in the opening and lethal in the endgame.

Formula: DynamicPly = BasePly + \lfloor \frac{DiscsOnBoard}{7} \rfloor
Benefit: High-level tactical precision exactly when the game becomes critical.

2. Strategic Blunder Injection

To avoid endless stalemate draws between high-level AIs, a "Blunder" logic is used.

Demo Mode: Always active; 20% chance to make a suboptimal move.
Player Mode: Toggleable via Web Portal to make the AI more "human."

3. Alpha-Beta Pruning & Column Ordering

The engine evaluates the center column first. This triggers pruning earlier in the search tree, skipping millions of unnecessary calculations and keeping the ESP32-C3 responsive.

📖 Code Architecture Details

🔄 State Machine

The software cycles through states:

MENU: Select mode using the rotary encoder.
PLAYING: Manages player turns and the gravity-acceleration drop animation.
DEMO: Auto-starts after inactivity. Randomizes Ply (3-6) and enforces blunders to ensure definitive game results.

🎨 Rendering & Mapping

The getIdx(x, y) function maps the 2D game board to the 1D NeoPixel array. The updateThinkingVisuals() function provides real-time feedback of the AI's internal search process by moving a pulsing disc across the top row.

🌐 Web Admin Portal

Connect to the "Connect4-Config" Access Point to adjust:

Base Ply: Minimum search depth.
Brightness: Global LED intensity.
Idle Timeout: Inactivity period before Demo Mode.
Toggles: Enable/Disable Blunders and Evolution Mode.

🛠 Setup & Installation

Install PlatformIO.
Add dependencies: FastLED, Encoder.
Set your WiFi Password in platformio.ini: -D WIFI_PASSWORD=\"your_pass\".
Upload to ESP32-C3.

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