Circuit Documentation

Summary

This circuit is designed to control a robot with four DC motors using an Arduino UNO microcontroller and an L298N motor driver. The robot's movements are directed via Bluetooth communication using an HC-06 Bluetooth module. The motors are powered by a 12V battery, which also supplies power to the motor driver. The Arduino UNO controls the motor driver by sending signals to dictate the direction and speed of the motors. The Bluetooth module allows for wireless control through a paired Bluetooth device.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• Used for controlling the motors and handling Bluetooth communication

Bluetooth HC-06

• Bluetooth module for wireless communication
• Interfaces with the Arduino for remote control commands

Battery 12V

• Provides power to the circuit
• Supplies the motor driver with the necessary voltage for motor operation

DC Motors (4x)

• Actuators that drive the robot's movement
• Controlled by the motor driver, which receives commands from the Arduino

L298N DC Motor Driver

• Dual H-bridge motor driver
• Used to control the direction and speed of the motors

Wiring Details

Arduino UNO

• 5V connected to Bluetooth HC-06 VCC
• GND connected to Bluetooth HC-06 GND
• Vin connected to L298N Motor Driver 5V
• D10 connected to L298N Motor Driver IN4
• D9 connected to L298N Motor Driver IN3
• D8 connected to L298N Motor Driver IN2
• D7 connected to L298N Motor Driver IN1
• D6 connected to L298N Motor Driver ENA
• D5 connected to L298N Motor Driver ENB
• D1 connected to Bluetooth HC-06 RXD
• D0 connected to Bluetooth HC-06 TXD

Bluetooth HC-06

• VCC connected to Arduino UNO 5V
• GND connected to Arduino UNO GND
• TXD connected to Arduino UNO D0
• RXD connected to Arduino UNO D1

Battery 12V

• + connected to L298N Motor Driver 12V
• - connected to L298N Motor Driver GND

DC Motors

• Two motors connected in parallel to L298N Motor Driver OUT4 and OUT3
• Two motors connected in parallel to L298N Motor Driver OUT2 and OUT1

L298N DC Motor Driver

• 5V connected to Arduino UNO Vin
• 12V connected to Battery 12V +
• GND connected to Battery 12V -
• ENA connected to Arduino UNO D6
• IN1 connected to Arduino UNO D7
• IN2 connected to Arduino UNO D8
• IN3 connected to Arduino UNO D9
• IN4 connected to Arduino UNO D10
• ENB connected to Arduino UNO D5
• OUT1 and OUT2 connected to two DC Motors
• OUT3 and OUT4 connected to two other DC Motors

Documented Code

// Define motor driver pins
const int ENA = 5;  // Enable pin for motor A (front-left & front-right wheels)
const int IN1 = 7;  // Input pin 1 for motor A
const int IN2 = 8;  // Input pin 2 for motor A
const int ENB = 6;  // Enable pin for motor B (back-left & back-right wheels)
const int IN3 = 9;  // Input pin 1 for motor B
const int IN4 = 10; // Input pin 2 for motor B

// Define Bluetooth module pins
#include <SoftwareSerial.h>
SoftwareSerial BT(10, 11);  // RX, TX

void setup() {
  // Set all motor driver pins as output
  pinMode(ENA, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(ENB, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);

  // Start Bluetooth communication
  BT.begin(9600);  // Start Bluetooth at 9600 baud rate
  Serial.begin(9600);  // Start Serial for debugging
}

void loop() {
  if (BT.available()) {
    char data = BT.read();  // Read the command from the Bluetooth app

    if (data == 'F') {
      moveForward();  // Move the robot forward
    }
    else if (data == 'B') {
      moveBackward();  // Move the robot backward
    }
    else if (data == 'L') {
      turnLeft();  // Turn the robot left
    }
    else if (data == 'R') {
      turnRight();  // Turn the robot right
    }
    else if (data == 'S') {
      stopRobot();  // Stop the robot
    }

    // Debugging: Print the command received via Bluetooth
    Serial.println(data);
  }
}

// Function to move the robot forward
void moveForward() {
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  analogWrite(ENA, 255);  // Set speed of motor A
  analogWrite(ENB, 255);  // Set speed of motor B
}

// Function to move the robot backward
void moveBackward() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
  analogWrite(ENA, 255);
  analogWrite(ENB, 255);
}

// Function to turn the robot left
void turnLeft() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  analogWrite(ENA, 255);
  analogWrite(ENB, 255);
}

// Function to turn the robot right
void turnRight() {
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
  analogWrite(ENA, 255);
  analogWrite(ENB, 255);
}

// Function to stop the robot
void stopRobot() {
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
  analogWrite(ENA, 0);
  analogWrite(ENB, 0);
}

The code provided is for the Arduino UNO microcontroller. It includes the setup and loop functions, which are standard in Arduino programming. The setup function initializes the motor driver pins and starts the Bluetooth and Serial communication. The loop function listens for Bluetooth commands to control the robot's movements. There are also functions defined for moving the robot forward, backward, turning left, turning right, and stopping the robot.