Circuit Documentation

Summary

This document provides a detailed overview of a Bluetooth-controlled motor driver circuit. The circuit consists of an Arduino UNO microcontroller, an HC-05 Bluetooth module, an L298N DC motor driver, two motors with wheels, and a 9V battery. The Arduino UNO is programmed to receive commands via Bluetooth to control the motors' movements.

Component List

9V Battery

• Description: Provides power to the circuit.
• Pins: -, +

HC-05 Bluetooth Module

• Description: Enables wireless communication between the Arduino and a Bluetooth-enabled device.
• Pins: Key, VCC, GND, TXD, RXD, State

Arduino UNO

• Description: Microcontroller used to control the motor driver and communicate with the Bluetooth module.
• Pins: UNUSED, IOREF, Reset, 3.3V, 5V, GND, Vin, A0, A1, A2, A3, A4, A5, SCL, SDA, AREF, D13, D12, D11, D10, D9, D8, D7, D6, D5, D4, D3, D2, D1, D0

Motor and Wheels

• Description: Provides movement to the system.
• Pins: vcc, GND

L298N DC Motor Driver

• Description: Controls the motors based on signals received from the Arduino.
• Pins: OUT1, OUT2, 12V, GND, 5V, OUT3, OUT4, 5V-ENA-JMP-I, 5V-ENA-JMP-O, +5V-J1, +5V-J2, ENA, IN1, IN2, IN3, IN4, ENB

Wiring Details

9V Battery

• - connected to:

  • L298N DC motor driver GND
  • Arduino UNO GND

• + connected to:

  • L298N DC motor driver 12V
  • Arduino UNO Vin

HC-05 Bluetooth Module

• VCC connected to:

  • Arduino UNO 5V

• GND connected to:

  • Arduino UNO GND

• RXD connected to:

  • Arduino UNO D12

• TXD connected to:

  • Arduino UNO D11

Arduino UNO

• 5V connected to:

  • HC-05 Bluetooth Module VCC

• GND connected to:

  • HC-05 Bluetooth Module GND
  • 9V Battery -
  • L298N DC motor driver GND

• Vin connected to:

  • 9V Battery +

• D12 connected to:

  • HC-05 Bluetooth Module RXD

• D11 connected to:

  • HC-05 Bluetooth Module TXD

• D10 connected to:

  • L298N DC motor driver ENA

• D9 connected to:

  • L298N DC motor driver ENB

• D5 connected to:

  • L298N DC motor driver IN1

• D4 connected to:

  • L298N DC motor driver IN2

• D3 connected to:

  • L298N DC motor driver IN3

• D2 connected to:

  • L298N DC motor driver IN4

L298N DC Motor Driver

• GND connected to:

  • 9V Battery -
  • Arduino UNO GND

• 12V connected to:

  • 9V Battery +

• ENA connected to:

  • Arduino UNO D10

• ENB connected to:

  • Arduino UNO D9

• IN1 connected to:

  • Arduino UNO D5

• IN2 connected to:

  • Arduino UNO D4

• IN3 connected to:

  • Arduino UNO D3

• IN4 connected to:

  • Arduino UNO D2

• OUT4 connected to:

  • Motor and wheels vcc

• OUT3 connected to:

  • Motor and wheels GND

• OUT1 connected to:

  • Motor and wheels vcc

• OUT2 connected to:

  • Motor and wheels GND

Motor and Wheels

• vcc connected to:

  • L298N DC motor driver OUT4
  • L298N DC motor driver OUT1

• GND connected to:

  • L298N DC motor driver OUT3
  • L298N DC motor driver OUT2

Documented Code

#include <SoftwareSerial.h>

// Motor driver pin definitions
int motor1_pin1 = 5;  // Motor 1 input pin 1
int motor1_pin2 = 4;  // Motor 1 input pin 2
int motor2_pin1 = 3;  // Motor 2 input pin 1
int motor2_pin2 = 2;  // Motor 2 input pin 2
int ENA = 10;         // Motor 1 Enable pin (for PWM control)
int ENB = 9;          // Motor 2 Enable pin (for PWM control)

// Bluetooth
SoftwareSerial BTSerial(11, 12);  // RX, TX pins for Bluetooth (adjust according to your wiring)
char Incoming_value = 0; // Variable to store incoming Bluetooth data

void setup() {
  // Pin modes for motor driver
  pinMode(motor1_pin1, OUTPUT);
  pinMode(motor1_pin2, OUTPUT);
  pinMode(motor2_pin1, OUTPUT);
  pinMode(motor2_pin2, OUTPUT);

  // Enable motor driver (for motor control)
  pinMode(ENA, OUTPUT);
  pinMode(ENB, OUTPUT);
  digitalWrite(ENA, HIGH);  // Enable motor 1
  digitalWrite(ENB, HIGH);  // Enable motor 2

  // Start serial communication at 9600 baud rate
  Serial.begin(9600);  // Serial monitor
  BTSerial.begin(9600);  // Bluetooth communication

  Serial.println("Motor Control Program Started");
  Serial.println("Send commands via Bluetooth: F = Forward, B = Backward, L = Left, R = Right, S = Stop");
}

void loop() {
  // Check if there's any data coming in from the Serial Monitor
  if (Serial.available() > 0) {
    Incoming_value = Serial.read();  // Read the incoming byte
    processCommand(Incoming_value);
  }

  // Check if there's any data coming in from the Bluetooth module
  if (BTSerial.available() > 0) {
    Incoming_value = BTSerial.read();  // Read the incoming byte
    Serial.print("Received command from Bluetooth: ");
    Serial.println(Incoming_value); // Debugging output
    processCommand(Incoming_value);
  }
}

// Function to process incoming commands
void processCommand(char command) {
  // Check the command and control the motors accordingly
  if (command == 'F') { // Forward
    Serial.println("Moving Forward");
    digitalWrite(motor1_pin1, LOW);
    digitalWrite(motor1_pin2, HIGH);
    digitalWrite(motor2_pin1, LOW);
    digitalWrite(motor2_pin2, HIGH);
  } 
  else if (command == 'B') { // Backward
    Serial.println("Moving Backward");
    digitalWrite(motor1_pin1, HIGH);
    digitalWrite(motor1_pin2, LOW);
    digitalWrite(motor2_pin1, HIGH);
    digitalWrite(motor2_pin2, LOW);
  } 
  else if (command == 'L') { // Left
    Serial.println("Turning Left");
    digitalWrite(motor1_pin1, LOW);
    digitalWrite(motor1_pin2, LOW);
    digitalWrite(motor2_pin1, LOW);
    digitalWrite(motor2_pin2, HIGH);
  } 
  else if (command == 'R') { // Right
    Serial.println("Turning Right");
    digitalWrite(motor1_pin1, HIGH);
    digitalWrite(motor1_pin2, LOW);
    digitalWrite(motor2_pin1, LOW);
    digitalWrite(motor2_pin2, LOW);
  } 
  else if (command == 'S') { // Stop
    Serial.println("Stopping Motors");
    digitalWrite(motor1_pin1, LOW);
    digitalWrite(motor1_pin2, LOW);
    digitalWrite(motor2_pin1, LOW);
    digitalWrite(motor2_pin2, LOW);
  }
  else {
    Serial.println("Invalid Command");
  }
}