Wireless Audio Transfer Using Laser Light (Arduino UNO)

 This project demonstrates wireless audio transmission using a laser beam.

Audio is converted into an electrical signal, modulated onto a laser, transmitted through air, and received using a light sensor. The Arduino processes the signal and outputs sound to a speaker.

How It Works (Simple Explanation)

Transmitter Side

1. Audio signal (from phone / mic module) goes into Arduino.

2. Arduino modulates the audio signal.

3. Laser diode intensity varies according to the audio signal.

4. Laser beam carries sound wirelessly.

Receiver Side

1. LDR / Photodiode detects laser light.

2. Light changes → electrical signal.

3. Arduino processes signal.

4. Amplifier boosts signal.

5. Speaker outputs sound.

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🧩 Components Required

🔴 Transmitter

• Arduino UNO

• Laser Diode Module (5V)

• Audio input (AUX / Microphone module)

• 10kΩ resistor

• Breadboard

• Jumper wires

• Power supply / USB

🔵 Receiver

• Arduino UNO

• LDR or Photodiode

• LM386 Audio Amplifier

• 8Ω Speaker

• 10kΩ resistor

• Capacitors (10µF, 100nF)

• Breadboard & wires

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🔌 Circuit Diagram (Text Representation)

Transmitter Circuit

Audio Signal  ----> A0 (Arduino)
Laser +        ----> D9 (PWM)
Laser -        ----> GND

Receiver Circuit

LDR One End    ----> A0 (Arduino)
LDR Other End ----> 5V
10kΩ Resistor ----> A0 to GND

Arduino D9    ----> LM386 Input
LM386 Output  ----> Speaker

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 Arduino Code

🔴 Transmitter Code

const int audioPin = A0;
const int laserPin = 9;

void setup() {
  pinMode(laserPin, OUTPUT);
}

void loop() {
  int audioValue = analogRead(audioPin);
  int pwmValue = map(audioValue, 0, 1023, 0, 255);
  analogWrite(laserPin, pwmValue);
}

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🔵 Receiver Code

const int ldrPin = A0;
const int speakerPin = 9;

void setup() {
  pinMode(speakerPin, OUTPUT);
}

void loop() {
  int lightValue = analogRead(ldrPin);
  int pwmValue = map(lightValue, 0, 1023, 0, 255);
  analogWrite(speakerPin, pwmValue);
}

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📈 Applications

• Wireless audio systems

• Secure optical communication

• Defense communication demo

• Li-Fi technology learning

• Science exhibitions & final year projects