🧠 Arduino Lie Detector (Skin Conductivity / GSR)

This is a simple Arduino-based lie detector prototype using Galvanic Skin Response (GSR) to measure changes in skin conductivity.

During the first 5 seconds, the system calibrates a baseline (skinConductivity). It then compares real-time readings to detect deviations, which are visualized through LEDs and plotted in real time.

🔧 Features

• Automatic 5-second calibration at startup
• LED feedback:
  • 🟢 Green LED → Conductivity below threshold (low stress)
  • 🟡 Yellow LED → Moderate increase (+10%)
  • 🔴 Red LED → High increase (+20%)
• Serial Plotter visualization with 4 signals:
  • Baseline
  • Baseline + 10% (tolerance)
  • Baseline + 20%
  • Real-time A0 reading

🧪 How It Works

1. Two electrodes are placed on the skin (e.g., fingers).
2. Arduino reads analog values from pin A0.
3. A baseline is computed as the average of 250 samples taken during the first 5 seconds.
4. The current reading is compared to this baseline:
   • If over +20% → Red LED ON
   • If over +10% → Yellow LED ON
   • If below +10% → Green LED ON

🖥️ Serial Plotter Output

Every cycle, the following values are sent (tab-separated):

1. skinConductivity (baseline)
2. skinConductivity + tolerance (10% above)
3. skinConductivity + 2 * tolerance (20% above)
4. value (real-time A0 reading)

This allows you to track the skin response over time via Arduino’s Serial Plotter.

🧰 Hardware Requirements

• Arduino Uno (or compatible board)
• 3 LEDs (Green, Yellow, Red) + resistors
• 3x 220Ω resistors
• 1x 1MΩ resistor
• Breadboard + jumper wires
• 1 human finger

📷 Preview

⚠️ Disclaimer

This project is for educational and experimental purposes only. GSR is not a reliable lie detector but can demonstrate physiological changes.

📄 License

GNU License