How to Build a Bluetooth-Controlled RC Car Using Arduino UNO, HC-05, and L298N Motor Driver

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Building a remote-controlled car is an exciting way to dive into robotics and electronics. In this project, we’ll guide you through creating a Bluetooth-controlled car using an Arduino UNO, HC-05 Bluetooth module, and L298N motor driver.


Step 1: Components You’ll Need

  1. Arduino UNO – The brain of your car.
  2. HC-05 Bluetooth Module – For wireless communication.
  3. L298N Motor Driver – To control motor speed and direction.
  4. DC Motors – Two or four motors for your wheels.
  5. Car Chassis – A sturdy frame for your car.
  6. 5V power bank– To power the motors.
  7. Jumper Wires – For connections.

 

Step 2: Circuit Connections

  1. HC-05 to Arduino:

    • VCC → Arduino 5V
    • GND → Arduino GND
    • TX → Arduino RX (Pin 0)
    • RX → Arduino TX (Pin 1)

  2. L298N Motor Driver to Arduino:

    • Motor-1-FW, Motor-1-BW→ Arduino Pins 8, 9
    • Motor-2-FW, Motor-2-BW → Arduino Pins 10, 11

  3. Power:

    • Connect the 5v power bank to the motor driver’s power input.
    • Share the ground between the battery and Arduino

Step 3: Write the Code

 


Use the Arduino IDE to upload the code. Here’s a snippet for controlling the motors:

// Pin definitions

int motor1fPin = 8;
int motor1bPin = 9;

int motor2fPin = 10;
int motor2bPin = 11;
String receivedData = "";

void setup() {
  pinMode(motor1fPin, OUTPUT);
  pinMode(motor1bPin, OUTPUT);
  pinMode(motor2fPin, OUTPUT);
  pinMode(motor2bPin, OUTPUT);
  Serial.begin(9600);
}

void loop() {

  if (Serial.available() > 0) {
    char receivedChar = Serial.read();
    delay(5);
    if (receivedChar == '\n') {
      if ((receivedData == "s") || (receivedData == "S")) {
        digitalWrite(motor1fPin, LOW);
        digitalWrite(motor1bPin, LOW);
        digitalWrite(motor2fPin, LOW);
        digitalWrite(motor2bPin, LOW);
      }
      else if ((receivedData == "f") || (receivedData == "F")) {
        digitalWrite(motor1fPin, LOW);
        digitalWrite(motor1bPin, LOW);
        digitalWrite(motor2fPin, LOW);
        digitalWrite(motor2bPin, LOW);
        delay(100);
        digitalWrite(motor1fPin, HIGH);
        digitalWrite(motor2fPin, HIGH);
      }
     else if ((receivedData == "b") || (receivedData == "B")) {
       digitalWrite(motor1fPin, LOW);
        digitalWrite(motor1bPin, LOW);
        digitalWrite(motor2fPin, LOW);
        digitalWrite(motor2bPin, LOW);
        delay(100);
        digitalWrite(motor1bPin, HIGH);
        digitalWrite(motor2bPin, HIGH);  
      }       
            
      else if ((receivedData == "l") || (receivedData == "L")) {
        digitalWrite(motor1fPin, LOW);
        digitalWrite(motor1bPin, LOW);
        digitalWrite(motor2fPin, LOW);
        digitalWrite(motor2bPin, LOW);
        delay(100);
        digitalWrite(motor2fPin, HIGH);        
      } 
       else if ((receivedData == "r") || (receivedData == "R")) {
        digitalWrite(motor1fPin, LOW);
        digitalWrite(motor1bPin, LOW);
        digitalWrite(motor2fPin, LOW);
        digitalWrite(motor2bPin, LOW);
        delay(100);
        digitalWrite(motor1fPin, HIGH);
       }
          
      receivedData = "";
    } else {
      receivedData = receivedData + receivedChar;
    }
  }
}

Step 4: Control with Your Smartphone

  • Install a Bluetooth control app like Bluetooth Controller or Serial Bluetooth Terminal.
  • Pair your smartphone with the HC-05 module (default password: 1234 or 0000).
  • Use commands like F (Forward), B (Backward), L (Left), R (Right), and S (Stop).

 

Step 5: Test Your Car


Once everything is connected and the code is uploaded, place your car on a flat surface and start sending commands via the Bluetooth app. Watch it zoom forward, turn, and stop!


Conclusion

This Bluetooth-controlled RC car project is an excellent way to learn about embedded systems, motor control, and wireless communication. With just a few components and some programming, you can build your very own RC car.

If you want to create your project   use :

 YouTube Video link:   https://youtu.be/C7xw1KN9w74

 Have questions or need help? Drop a comment below or check out our video tutorial for a detailed walk through!






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