Building a Bluetooth Controlled Car with Arduino

 

Building a Bluetooth Controlled Car with Arduino

In this blog, we’ll walk through creating a Bluetooth-controlled car using an Arduino and a Bluetooth module. This project is a great way to delve into the world of robotics, combining mechanical control with wireless communication. By the end of this tutorial, you'll have a basic understanding of how to control a car using your smartphone via Bluetooth.

Introduction

Controlling devices wirelessly is not only convenient but also opens up a myriad of possibilities in robotics and IoT projects. By integrating Bluetooth into an Arduino-powered car, we can create a simple yet powerful system to navigate and control a car remotely. We will cover the necessary hardware, software setup, and code implementation to get your Bluetooth-controlled car up and running.

Required Components

1. Arduino Uno (or any other compatible board)

2. HC-05 Bluetooth module

3. Motor driver module (L298N or similar)

4. DC motors with wheels (2 or 4 depending on your design)

5. Chassis for the car

6. Power supply (battery pack)

7. Jumper wires

8. Breadboard (optional)

Hardware Setup

Connecting the Motors

First, connect the DC motors to the motor driver module. The L298N motor driver has four output pins to connect two motors:

• Connect one motor to OUT1 and OUT2.

• Connect the other motor to OUT3 and OUT4.

Connecting the Motor Driver to Arduino

Next, connect the motor driver inputs to the Arduino:

• IN1 to pin 6 (left motor forward)

• IN2 to pin 5 (left motor reverse)

• IN3 to pin 11 (right motor forward)

• IN4 to pin 10 (right motor reverse)

• Connect the motor driver’s VCC to the 12V power supply (battery pack).

• Connect GND from the motor driver to GND on the Arduino.

Connecting the Bluetooth Module

The HC-05 Bluetooth module has four pins:

• VCC: Connect to 5V on the Arduino.

• GND: Connect to GND on the Arduino.

• TXD: Connect to RX on the Arduino (pin 0).

• RXD: Connect to TX on the Arduino (pin 1).

Circuit Diagram 

Software Setup

Arduino IDE

Make sure you have the Arduino IDE installed on your computer. If not, download it from the Arduino website and install it.

Writing the Code

Here is the complete code to control the car via Bluetooth. The code reads commands sent from a Bluetooth-enabled device and controls the motors accordingly.

char t;

 

void setup() {

  pinMode(13, OUTPUT);   // Left motors forward

  pinMode(12, OUTPUT);   // Left motors reverse

  pinMode(11, OUTPUT);  // Right motors forward

  pinMode(10, OUTPUT);  // Right motors reverse

  Serial.begin(9600);

}

 

void loop() {

  if (Serial.available()) {

    t = Serial.read();

    Serial.println(t);

  }

 

  if (t == 'F') {  // Move forward (all motors rotate in forward direction)

    digitalWrite(6, HIGH);

    digitalWrite(11, HIGH);

    digitalWrite(10, LOW);

    digitalWrite(5, LOW);

  } else if (t == 'B') {  // Move reverse (all motors rotate in reverse direction)

    digitalWrite(5, HIGH);

    digitalWrite(10, HIGH);

    digitalWrite(11, LOW);

    digitalWrite(6, LOW);

  } else if (t == 'R') {  // Turn right

    digitalWrite(5, LOW);

    digitalWrite(10, LOW);

    digitalWrite(11, LOW);

    digitalWrite(6, HIGH);

  } else if (t == 'L') {  // Turn left

    digitalWrite(5, LOW);

    digitalWrite(10, LOW);

    digitalWrite(11, HIGH);

    digitalWrite(6, LOW);

  } else if (t == 'T') {  // Stop (all motors stop)

    digitalWrite(6, LOW);

    digitalWrite(5, LOW);

    digitalWrite(11, LOW);

    digitalWrite(10, LOW);

  }

  delay(100);

}

Testing the Bluetooth Controlled Car

1. Upload the Code: Upload the code to your Arduino board using the Arduino IDE.

2. Pair the Bluetooth Module: Use your smartphone or another Bluetooth-enabled device to pair with the HC-05 module. The default pairing code is usually "1234" or "0000".

3. Control the Car: Install a Bluetooth terminal app on your smartphone (e.g., Serial Bluetooth Terminal for Android or Bluetooth Terminal for iOS). Connect to the HC-05 module through the app and send the commands 'F', 'B', 'R', 'L', and 'T' to control the car.

Practical Applications

Building a Bluetooth-controlled car is not only a fun project but also has several practical applications and learning outcomes:

1. Robotics Education: This project serves as an excellent introduction to robotics, teaching fundamental concepts like motor control and wireless communication.

2. IoT Projects: Understanding how to integrate Bluetooth with Arduino opens up possibilities for numerous IoT applications, from home automation to remote sensing.

3. DIY Projects: This car can be a base for more complex DIY projects, such as adding sensors for obstacle avoidance or integrating a camera for remote monitoring.

Troubleshooting Tips

1. Check Connections: Ensure all connections are secure and correctly aligned. Loose connections can lead to inconsistent behavior.

2. Correct Baud Rate: Verify that the baud rate for serial communication matches the settings on both the Arduino and the Bluetooth module.

3. Power Supply: Ensure that the motors and Arduino are receiving adequate power. A low battery can cause motors to perform poorly.

4. Serial Communication: Make sure the Bluetooth module is correctly paired with your smartphone and the terminal app is connected.

Conclusion

Creating a Bluetooth-controlled car with Arduino is an engaging and educational project that combines various aspects of electronics, programming, and wireless communication. By following this guide, you can build a simple yet functional car that can be controlled via Bluetooth, providing a strong foundation for more advanced robotics and IoT projects.

With the knowledge gained from this project, you can further explore enhancements such as adding ultrasonic sensors for obstacle detection, integrating GPS for navigation, or using different communication protocols like Wi-Fi for extended range. The possibilities are endless, and the skills you develop here will serve you well in future projects.