Introduction

A Bluetooth Controlled Car is a wireless robotic vehicle that can be controlled using a smartphone via Bluetooth communication. Instead of manual switches, the car responds to commands sent from a mobile application.

This project is a perfect example of wireless control and embedded system integration.

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Objective of the Project

• To control a robotic car using Bluetooth.
• To understand wireless communication.
• To interface Bluetooth module with Arduino.
• To control DC motors using a motor driver.

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Working Principle

The system works on Bluetooth communication.

How It Works

1. User sends command from mobile app.
2. Bluetooth module (HC-05) receives the command.
3. Arduino reads the command.
4. Motor driver moves the car accordingly.
5. Car changes direction based on input.

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Components Required

• Arduino Uno
• Bluetooth Module (HC-05)
• Motor Driver (L298N / L293D)
• DC Motors with Wheels
• Robot Chassis
• Battery
• Jumper Wires

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Circuit Diagram

Bluetooth Module (HC-05)

VCC -> 5V
GND -> GND
TX  -> RX (Arduino)
RX  -> TX (Arduino via voltage divider)

Motor Driver (L298N)

IN1 -> D8
IN2 -> D9
IN3 -> D10
IN4 -> D11
ENA -> D5
ENB -> D6

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Arduino Code for Bluetooth Controlled Car

char command;

int motor1A = 8;
int motor1B = 9;
int motor2A = 10;
int motor2B = 11;

void setup() {
  pinMode(motor1A, OUTPUT);
  pinMode(motor1B, OUTPUT);
  pinMode(motor2A, OUTPUT);
  pinMode(motor2B, OUTPUT);

  Serial.begin(9600);
}

void loop() {
  if (Serial.available()) {
    command = Serial.read();

    if (command == 'F') forward();
    else if (command == 'B') backward();
    else if (command == 'L') left();
    else if (command == 'R') right();
    else if (command == 'S') stopCar();
  }
}

void forward() {
  digitalWrite(motor1A, HIGH);
  digitalWrite(motor1B, LOW);
  digitalWrite(motor2A, HIGH);
  digitalWrite(motor2B, LOW);
}

void backward() {
  digitalWrite(motor1A, LOW);
  digitalWrite(motor1B, HIGH);
  digitalWrite(motor2A, LOW);
  digitalWrite(motor2B, HIGH);
}

void left() {
  digitalWrite(motor1A, LOW);
  digitalWrite(motor1B, HIGH);
  digitalWrite(motor2A, HIGH);
  digitalWrite(motor2B, LOW);
}

void right() {
  digitalWrite(motor1A, HIGH);
  digitalWrite(motor1B, LOW);
  digitalWrite(motor2A, LOW);
  digitalWrite(motor2B, HIGH);
}

void stopCar() {
  digitalWrite(motor1A, LOW);
  digitalWrite(motor1B, LOW);
  digitalWrite(motor2A, LOW);
  digitalWrite(motor2B, LOW);
}

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Code Explanation

• Bluetooth module receives command.
• Arduino decodes command.
• Motors respond to movement commands.
• Car stops when stop command is received.

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Advantages

• Wireless control
• Easy to use
• Low cost
• Expandable system

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Applications

• Robotics learning
• Surveillance vehicles
• Smart toy cars
• Industrial inspection

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Future Enhancements

• Speed control using PWM
• Camera integration
• Voice control
• IoT-based control

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Conclusion

The Bluetooth Controlled Car is an engaging and educational robotics project that demonstrates wireless communication and motor control. It is ideal for students learning embedded systems and automation.