In this lesson, we’ll build a remote-controlled car using Arduino, a Bluetooth module, and motors. Get ready to drive your own creation wirelessly!

Objective: Learn how to control a remote control car using Arduino and a Bluetooth module.

Materials:

• Arduino Uno board
• Breadboard
• DC motors (2)
• Motor driver module (L298N)
• Bluetooth module (HC-05 or similar)
• Jumper wires
• 9V battery (or power supply)
• Remote control device (Android/iOS app or Bluetooth remote)
• Computer with Arduino IDE software installed

Steps:

1. Review: Recap previous lessons and components, including motors, motor drivers, and Bluetooth communication.
2. Meet the Bluetooth Module: Introduce the Bluetooth module and explain how it enables wireless communication.
3. Building the Circuit: Connect the motors, motor driver, Bluetooth module, Arduino board, and battery to the breadboard.

Step 1: Connecting the Bluetooth Module

1. Find the pins on the Bluetooth module: It usually has pins for RX, TX, VCC, GND, and sometimes a status indicator LED.
2. Connect the Bluetooth module to the Arduino:
   • Connect the module’s RX pin to the Arduino’s digital pin 10.
   • Connect the module’s TX pin to the Arduino’s digital pin 11.
   • Connect the module’s VCC pin to the Arduino’s 5V pin.
   • Connect the module’s GND pin to the Arduino’s GND pin.
3. Power on the Bluetooth module: You might need to use a separate power supply if it doesn’t have a 5V output.

Step 2: Connecting the Motor Driver and Motors (Review)

• Follow the steps from Lesson 7 to connect the motor driver (L298N) and the motors to the Arduino and the battery.

Step 3: Programming the Arduino

1. Open the Arduino IDE.
2. Download and install the SoftwareSerial library: Go to “Sketch” -> “Include Library” -> “Manage Libraries…” and search for “SoftwareSerial”. Install the library.
3. Copy and paste the following code (adjust for your specific Bluetooth module and motor driver):

#include <SoftwareSerial.h> // Include SoftwareSerial library

SoftwareSerial bluetooth(10, 11); // Define Bluetooth module pins

const int motor1Pin1 = 9; // Motor 1 control pin 1
const int motor1Pin2 = 10; // Motor 1 control pin 2
const int motor2Pin1 = 5; // Motor 2 control pin 1
const int motor2Pin2 = 6; // Motor 2 control pin 2

void setup() {
  bluetooth.begin(9600); // Initialize Bluetooth module
  pinMode(motor1Pin1, OUTPUT);
  pinMode(motor1Pin2, OUTPUT);
  pinMode(motor2Pin1, OUTPUT);
  pinMode(motor2Pin2, OUTPUT);
}

void loop() {
  if (bluetooth.available() > 0) {
    char data = bluetooth.read(); // Read data from Bluetooth

    switch (data) {
      case 'F':
        forward(); // Move forward
        break;
      case 'B':
        backward(); // Move backward
        break;
      case 'L':
        left(); // Turn left
        break;
      case 'R':
        right(); // Turn right
        break;
      case 'S':
        stop(); // Stop
        break;
    }
  }
}

// Define motor functions
void forward() {
  // ...
}

void backward() {
  // ...
}

void left() {
  // ...
}

void right() {
  // ...
}

void stop() {
  // ...
}

1. Implement the motor functions (forward, backward, left, right, stop):
   • Refer to your motor driver’s documentation to figure out how to control the motors using the digitalWrite() function.
2. Upload the code to the Arduino board.

Step 4: Pair the Bluetooth Module and Test

1. Pair the Bluetooth module with your remote control device: Refer to the instructions for your Bluetooth module and remote control device.
2. Send commands from the remote: Use the remote control device to send commands like ‘F’ (forward), ‘B’ (backward), ‘L’ (left), ‘R’ (right), and ‘S’ (stop).
3. Observe the car’s movement: Your car should respond to the commands and move accordingly.

Congratulations! You’ve built a remote-controlled car!

Let’s Experiment:

• Adjust the speed: Change the delay() values in the motor functions to control the car’s speed.
• Add more functionality: Try adding more commands to control things like headlights, sounds, or other features.
• Customize the car: Design and build a chassis for your car to make it more robust and stylish!

Keep experimenting with motors, Bluetooth, and have fun with Arduino!