⚙️ Working Principle

This project implements a complete Morse Code communication system using two microprocessors:
one for encoding and transmitting the message, and another for receiving and decoding the signal.

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📤 Transmitter Unit (Encoding & LED Signaling)

1. The first microprocessor takes an input message (predefined in code)
2. Each character is converted into Morse code dot (.) and dash (–) patterns
3. The encoded signals are transmitted using an LED
4. A dot produces a short LED blink, while a dash produces a longer blink
5. Proper time delays are maintained between symbols and letters

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📥 Receiver Unit (LDR Sensing & Decoding)

1. The second microprocessor uses an LDR (Light Dependent Resistor) to detect LED flashes
2. Light pulses are converted into electrical signals
3. Signal durations are measured to distinguish dots and dashes
4. The Morse patterns are decoded back into readable characters
5. The decoded message is displayed via serial monitor or output device

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⏱ Timing Standard Used

Signal	Duration
Dot (.)	Short pulse
Dash (–)	3 × dot duration
Symbol gap	Dot duration
Letter gap	3 × dot duration
Word gap	7 × dot duration

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International Morse Code

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🔌 Transmitter Pin Connections

Component	Pin	Microprocessor Pin
LED	Anode (+)	Digital Pin 9
LED	Cathode (–)	GND
Buzzer (optional)	+	Digital Pin 10
Buzzer	–	GND
Power	VCC	5V
Ground	GND	GND

📡 Receiver Pin Connections

Component	Pin	Microprocessor Pin
LDR	One end	Analog Pin A0
LDR	Other end	5V
Resistor (10kΩ)	Between A0 & GND	Voltage divider
Output Display (Serial/LCD)	Data	RX/TX or I2C
Power	VCC	5V
Ground	GND	GND

Note: The LDR and resistor form a voltage divider circuit to convert light intensity into a readable analog signal.

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📐 System Block Diagram

📤 Transmitter Unit

Text Input → Microprocessor → Morse Encoder → LED Driver → LED Signal Output

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📥 Receiver Unit

LED Light Signal → LDR Sensor → Signal Conditioning → Microprocessor → Morse Decoder → Output Display

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⭐ Advantages

• Wireless communication using light
• Simple and low-cost components
• Easy to implement and understand
• Demonstrates real communication principles
• No RF interference
• Suitable for educational use

🌍 Applications

• Basic optical communication systems
• Learning embedded communication concepts
• Emergency signaling systems
• Secure short-range communication
• Educational electronics projects
• Assistive communication tools

This dual-microprocessor approach demonstrates wireless optical communication using light signals and embedded decoding logic.