Project Documentation

Arduino UNO and L298N DC Motor Driver Bluetooth Controlled Car

Circuit Documentation

Summary

This document provides a detailed overview of a Bluetooth-controlled car circuit. The circuit consists of an Arduino UNO microcontroller, an L298N DC motor driver, a 12V battery, and four motor and wheel assemblies. The Arduino UNO is programmed to control the motors based on commands received via Bluetooth.

Component List

L298N DC Motor Driver
- Description: A dual H-Bridge motor driver that allows control of the speed and direction of two DC motors.
- 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
Arduino UNO
- Description: A microcontroller board based on the ATmega328P, used for controlling the motor driver and receiving Bluetooth commands.
- 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
Battery 12V
- Description: A 12V battery used to power the motor driver and the Arduino UNO.
- Pins: +, -
Motor and Wheels
- Description: DC motors with attached wheels, used for driving the car.
- Pins: vcc, GND

Wiring Details

L298N DC Motor Driver

OUT1 is connected to the vcc pins of two motor and wheel assemblies.
OUT2 is connected to the GND pins of the same two motor and wheel assemblies.
12V is connected to the + pin of the 12V battery.
GND is connected to the - pin of the 12V battery and the GND pin of the Arduino UNO.
5V is connected to the Vin pin of the Arduino UNO.
OUT3 is connected to the GND pins of the other two motor and wheel assemblies.
OUT4 is connected to the vcc pins of the same two motor and wheel assemblies.
ENA is connected to the D6 pin of the Arduino UNO.
IN1 is connected to the D4 pin of the Arduino UNO.
IN2 is connected to the D7 pin of the Arduino UNO.
IN3 is connected to the D8 pin of the Arduino UNO.
IN4 is connected to the D9 pin of the Arduino UNO.
ENB is connected to the D5 pin of the Arduino UNO.

Arduino UNO

GND is connected to the - pin of the 12V battery and the GND pin of the L298N DC motor driver.
Vin is connected to the 5V pin of the L298N DC motor driver.
D6 is connected to the ENA pin of the L298N DC motor driver.
D4 is connected to the IN1 pin of the L298N DC motor driver.
D7 is connected to the IN2 pin of the L298N DC motor driver.
D8 is connected to the IN3 pin of the L298N DC motor driver.
D9 is connected to the IN4 pin of the L298N DC motor driver.
D5 is connected to the ENB pin of the L298N DC motor driver.

Battery 12V

+ is connected to the 12V pin of the L298N DC motor driver.
- is connected to the GND pin of the Arduino UNO and the GND pin of the L298N DC motor driver.

Motor and Wheels

vcc of the first two motor and wheel assemblies is connected to the OUT1 pin of the L298N DC motor driver.
GND of the first two motor and wheel assemblies is connected to the OUT2 pin of the L298N DC motor driver.
vcc of the other two motor and wheel assemblies is connected to the OUT4 pin of the L298N DC motor driver.
GND of the other two motor and wheel assemblies is connected to the OUT3 pin of the L298N DC motor driver.

Code Documentation

Arduino UNO Code

// Arduino Bluetooth Controlled Car
// Before uploading the code you have to install the necessary library
// Note - Disconnect the Bluetooth Module before hitting the upload button otherwise you'll get a compilation error message.
// AFMotor Library https://learn.adafruit.com/adafruit-motor-shield/library-install 
// After downloading the library open Arduino IDE >> go to sketch >> Include Library >> ADD. ZIP Library >> Select the downloaded 
// ZIP File >> Open it >> Done
// Now You Can Upload the Code without any problem but make sure the bt module isn't connected with Arduino while uploading code

#include <AFMotor.h>

// initial motors pin
AF_DCMotor motor1(1, MOTOR12_1KHZ); 
AF_DCMotor motor2(2, MOTOR12_1KHZ); 
AF_DCMotor motor3(3, MOTOR34_1KHZ);
AF_DCMotor motor4(4, MOTOR34_1KHZ);

char command; 

void setup() 
{       
  Serial.begin(9600);  // Set the baud rate to your Bluetooth module.
}

void loop(){
  if(Serial.available() > 0){ 
    command = Serial.read(); 
    Stop(); // initialize with motors stopped
    // Change pin mode only if new command is different from previous.   
    // Serial.println(command);
    switch(command){
    case 'F':  
      forward();
      break;
    case 'B':  
       back();
      break;
    case 'L':  
      left();
      break;
    case 'R':
      right();
      break;
    }
  } 
}

void forward()
{
  motor1.setSpeed(255); // Define maximum velocity
  motor1.run(FORWARD); // rotate the motor clockwise
  motor2.setSpeed(255); // Define maximum velocity
  motor2.run(FORWARD); // rotate the motor clockwise
  motor3.setSpeed(255); // Define maximum velocity
  motor3.run(FORWARD); // rotate the motor clockwise
  motor4.setSpeed(255); // Define maximum velocity
  motor4.run(FORWARD); // rotate the motor clockwise
}

void back()
{
  motor1.setSpeed(255); // Define maximum velocity
  motor1.run(BACKWARD); // rotate the motor anti-clockwise
  motor2.setSpeed(255); // Define maximum velocity
  motor2.run(BACKWARD); // rotate the motor anti-clockwise
  motor3.setSpeed(255); // Define maximum velocity
  motor3.run(BACKWARD); // rotate the motor anti-clockwise
  motor4.setSpeed(255); // Define maximum velocity
  motor4.run(BACKWARD); // rotate the motor anti-clockwise
}

void left()
{
  motor1.setSpeed(255); // Define maximum velocity
  motor1.run(BACKWARD); // rotate the motor anti-clockwise
  motor2.setSpeed(255); // Define maximum velocity
  motor2.run(BACKWARD); // rotate the motor anti-clockwise
  motor3.setSpeed(255); // Define maximum velocity
  motor3.run(FORWARD);  // rotate the motor clockwise
  motor4.setSpeed(255); // Define maximum velocity
  motor4.run(FORWARD);  // rotate the motor clockwise
}

void right()
{
  motor1.setSpeed(255); // Define maximum velocity
  motor1.run(FORWARD); // rotate the motor clockwise
  motor2.setSpeed(255); // Define maximum velocity
  motor2.run(FORWARD); // rotate the motor clockwise
  motor3.setSpeed(255); // Define maximum velocity
  motor3.run(BACKWARD); // rotate the motor anti-clockwise
  motor4.setSpeed(255); // Define maximum velocity
  motor4.run(BACKWARD); // rotate the motor anti-clockwise
} 

void Stop()
{
  motor1.setSpeed(0); // Define minimum velocity
  motor1.run(RELEASE); // stop the motor when release the button
  motor2.setSpeed(0); // Define minimum velocity
  motor2.run(RELEASE); // rotate the motor clockwise
  motor3.setSpeed(0); // Define minimum velocity
  motor3.run(RELEASE); // stop the motor when release the button
  motor4.setSpeed(0); // Define minimum velocity
  motor4.run(RELEASE); // stop the motor when release the button
}

This code initializes the motors and sets up the serial communication for