Project Documentation

Arduino UNO and L298N Bluetooth Controlled Robotic 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, an HC-05 Bluetooth module, 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 circuit.
- 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
HC-05 Bluetooth Module
- Description: A Bluetooth module used for wireless communication with the Arduino UNO.
- Pins: EN, VCC, GND, TXD, RXD, STATE
Battery 12V
- Description: A 12V battery used to power the circuit.
- Pins: +, -
Motor and Wheels (4 units)
- Description: DC motors with attached wheels used for driving the car.
- Pins: vcc, GND

Wiring Details

L298N DC Motor Driver

OUT1 connected to vcc of the first motor and wheels
OUT2 connected to GND of the first motor and wheels
12V connected to + of the 12V battery
GND connected to GND of the Arduino UNO and - of the 12V battery
5V connected to Vin of the Arduino UNO
OUT3 connected to GND of the third motor and wheels
OUT4 connected to vcc of the third motor and wheels
ENA connected to D6 of the Arduino UNO
IN1 connected to D4 of the Arduino UNO
IN2 connected to D7 of the Arduino UNO
IN3 connected to D8 of the Arduino UNO
IN4 connected to D9 of the Arduino UNO
ENB connected to D5 of the Arduino UNO

Arduino UNO

GND connected to GND of the HC-05 Bluetooth module and - of the 12V battery
Vin connected to 5V of the L298N DC motor driver
5V connected to VCC of the HC-05 Bluetooth module
D1 connected to RXD of the HC-05 Bluetooth module
D0 connected to TXD of the HC-05 Bluetooth module
D6 connected to ENA of the L298N DC motor driver
D4 connected to IN1 of the L298N DC motor driver
D7 connected to IN2 of the L298N DC motor driver
D8 connected to IN3 of the L298N DC motor driver
D9 connected to IN4 of the L298N DC motor driver
D5 connected to ENB of the L298N DC motor driver

HC-05 Bluetooth Module

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

Battery 12V

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

Motor and Wheels

First Motor:
- vcc connected to OUT1 of the L298N DC motor driver
- GND connected to OUT2 of the L298N DC motor driver
Second Motor:
- vcc connected to OUT1 of the L298N DC motor driver
- GND connected to OUT2 of the L298N DC motor driver
Third Motor:
- vcc connected to OUT4 of the L298N DC motor driver
- GND connected to OUT3 of the L298N DC motor driver
Fourth Motor:
- vcc connected to OUT4 of the L298N DC motor driver
- GND connected to OUT3 of the L298N DC motor driver

Documented 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);