Hand LED Controller

Features

• Real-time hand tracking using cam
• Detects each finger pos in real-time
• Send commands to Arduino via serial
• Each raised finger turns ON its assigned LED; lowering it turns it OFF

Project Structure

├── src/
│   ├── main.py              # Python script (hand tracker)
│   └── sketch/
│       └── sketch.ino       # Arduino sketch
│   └── wiring diagram/
│       └── circuit.png      # Wiring diagram
├── requirements.txt
└── README.md

Arduino side

Hardware

• Arduino Uno R3
• 5 LED and 220 ohm resistor
• Jumper wires
• Breadboard

Software

Open src/sketch/sketch.ino using Arduino IDE and upload to your board

Reminder: Make sure to select the correct COM port:

• In Arduino IDE: Tools > Port
• In Python code: Edit the serial port in main.py serial.port = 'COM3' with your device port

You can find the correct COM port in Arduino IDE after connecting the board.

Wiring Diagram

Finger to LED Mapping

Finger	LED Pin on Arduino
Thumb	8
Index Finger	9
Middle Finger	10
Ring Finger	11
Pinky Finger	12

Python side

Dependencies

pip install -r requirements.txt

Run the Script

Make sure your Arduino is connected and update the COM port in main.py:

serial.port = "COM3"  # Replace with your actual COM port

Then run:

python src/main.py

This will open your webcam and start gesture detection.

Serial Communication

The Python script detects a single hand using MediaPipe and checks if each finger is raised. It sends a 5-bit binary command (followed by *) to the Arduino through the serial port.

Finger	Bit Position	Detection Logic
Thumb	0	Tip (4) is left of joint (3)
Index Finger	1	Tip (8) is above joint (7)
Middle Finger	2	Tip (12) is above joint (11)
Ring Finger	3	Tip (16) is above joint (15)
Pinky Finger	4	Tip (20) is above joint (19)

Example output:

• 11111* → All fingers up
• 01000* → Only index finger up
• 00000* → All fingers down

These strings are sent over serial like:

serial.write("10110*".encode('utf-8'))

On the Arduino side, you can read the string, parse each bit, and control LEDs or devices accordingly.

How It Works

1. Hand Detection (Python + MediaPipe)
   The webcam captures live video. MediaPipe detects a hand and tracks 21 keypoints (landmarks) on it.

2. Finger State Detection
   For each finger, we check if it's raised using the position of key landmarks:

   • Thumb: checks if tip is to the left of its joint.
   • Fingers: checks if tip is above the lower joint.

3. Binary Encoding
   Each finger’s state is encoded as 1 (up) or 0 (down), forming a 5-bit binary string like 10110.

4. Serial Communication to Arduino
   The binary string with a * suffix (e.g. 10110*) is sent over the serial port to the Arduino.

5. Arduino Action
   Arduino reads the string, decodes it, and turns LEDs ON/OFF depending on the combination of finger states.

Credits

Uses:

• MediaPipe Hands
• OpenCV
• Arduino Serial Communication

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License

Licensed under the MIT License. You can use, modify, and share this freely with attribution.