Circuit Documentation

Summary

This circuit is designed to control two DC motors using an Arduino UNO microcontroller and an L298N DC motor driver. It includes a Bluetooth HC-06 module for wireless communication, allowing the motors to be controlled remotely via Bluetooth commands. The circuit is powered by a 9V battery connected through a rocker switch and also includes a 4 x AAA battery mount connected to a power jack for an alternative power source.

Component List

Arduino UNO

• Microcontroller board based on the ATmega328P
• It has 14 digital input/output pins, 6 analog inputs, a 16 MHz quartz crystal, a USB connection, a power jack, an ICSP header, and a reset button.

Rocker Switch

• A simple on/off switch that controls the connection of the circuit to the power source.

DC Motor (x2)

• Electric motors that convert DC electrical energy into mechanical energy.

Bluetooth HC-06

• A Bluetooth module that allows for wireless communication with the Arduino.

4 x AAA Battery Mount

• A battery holder for four AAA batteries, providing an alternative power source.

9V Battery

• A standard 9V battery used to power the circuit.

L298N DC Motor Driver

• A motor driver module capable of driving two DC motors or one stepper motor.

Power Jack

• A connector that allows the circuit to be powered by an external power supply.

Wiring Details

Arduino UNO

• 5V connected to Bluetooth HC-06 VCC
• GND connected to Bluetooth HC-06 GND, L298N GND, and 9V Battery -
• D10 connected to L298N ENA
• D9 connected to L298N IN1
• D8 connected to L298N IN2
• D7 connected to L298N IN3
• D6 connected to L298N IN4
• D5 connected to L298N ENB
• D4 connected to Bluetooth HC-06 TXD
• D2 connected to Bluetooth HC-06 RXD

Rocker Switch

• output connected to L298N 12V
• input connected to 9V Battery +

DC Motor #1

• pin 1 connected to L298N OUT4
• pin 2 connected to L298N OUT3

DC Motor #2

• pin 1 connected to L298N OUT2
• pin 2 connected to L298N OUT1

Bluetooth HC-06

• VCC connected to Arduino UNO 5V
• GND connected to Arduino UNO GND
• TXD connected to Arduino UNO D4
• RXD connected to Arduino UNO D2

4 x AAA Battery Mount

• - connected to Power Jack NEGATIF
• + connected to Power Jack POSITIF

9V Battery

• - connected to Arduino UNO GND, L298N GND
• + connected to Rocker Switch input

L298N DC Motor Driver

• GND connected to Arduino UNO GND, 9V Battery -
• ENA connected to Arduino UNO D10
• IN1 connected to Arduino UNO D9
• IN2 connected to Arduino UNO D8
• IN3 connected to Arduino UNO D7
• IN4 connected to Arduino UNO D6
• ENB connected to Arduino UNO D5
• 12V connected to Rocker Switch output
• OUT1 connected to DC Motor #2 pin 2
• OUT2 connected to DC Motor #2 pin 1
• OUT3 connected to DC Motor #1 pin 2
• OUT4 connected to DC Motor #1 pin 1

Power Jack

• NEGATIF connected to 4 x AAA Battery Mount -
• POSITIF connected to 4 x AAA Battery Mount +

Documented Code

#include <SoftwareSerial.h>
SoftwareSerial BT(4,2); // Bluetooth communication on pins D4 (TX) and D2 (RX)

// Motor 1
int ENA = 10; // Enable pin for motor A
int IN1 = 9;  // Input 1 for motor A
int IN2 = 8;  // Input 2 for motor A

// Motor 2
int ENB = 5;  // Enable pin for motor B
int IN3 = 7;  // Input 3 for motor B
int IN4 = 6;  // Input 4 for motor B

void setup() {
  Serial.begin(9600); // Start serial communication at 9600 baud rate
  BT.begin(9600);     // Start Bluetooth communication at 9600 baud rate

  // Set motor control pins as outputs
  pinMode(ENA, OUTPUT);
  pinMode(ENB, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
}

void loop() {
  if (BT.available()) { // Check if there is Bluetooth data available
    char data = BT.read(); // Read the incoming byte

    switch(data) {
      case 'a': // Command to move forward
        Forward();
        break;
      case 'r': // Command to move backward
        Backward();
        break;
      case 'd': // Command to turn right
        Right();
        break;
      case 'g': // Command to turn left
        Left();
        break;
      case 'p': // Command to stop
        Stop();
        break;
    }
  }
}

void Forward() {
  // Set motor A direction and speed
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 255); // Full speed
  // Set motor B direction and speed
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  analogWrite(ENB, 255); // Full speed
}

void Right() {
  // Set motor A to reverse direction at a slower speed
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  analogWrite(ENA, 100); // Reduced speed
  // Set motor B to forward direction at a slower speed
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  analogWrite(ENB, 100); // Reduced speed
}

void Left() {
  // Set motor A to forward direction at a slower speed
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 100); // Reduced speed
  // Set motor B to reverse direction at a slower speed
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
  analogWrite(ENB, 100); // Reduced speed
}

void Backward() {
  // Set motor A to reverse direction and speed
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  analogWrite(ENA, 255); // Full speed
  // Set motor B to reverse direction and speed
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
  analogWrite(ENB, 255); // Full speed
}

void Stop() {
  // Stop motor A
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 0); // No speed
  // Stop motor B
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
  analogWrite(ENB, 0); // No speed
}

This code is designed to be uploaded to the Arduino UNO microcontroller. It sets up a SoftwareSerial connection for Bluetooth communication and defines functions to control the direction and speed of two DC motors using the L298N motor driver. The Arduino listens for Bluetooth commands to control the motors: 'a' for forward, 'r' for backward, 'd' for right, 'g' for left, and 'p' for stop.