Project Documentation

Bluetooth-Controlled Arduino UNO Robotic Car with L298N Motor Driver

Circuit Documentation

Summary of the Circuit

This circuit is designed to control a car using Bluetooth technology. It consists of an Arduino UNO microcontroller that interfaces with a Bluetooth HC-06 module for wireless communication and an L298N DC motor driver to control two hobby motors. The motors are powered by 9V batteries connected through a 2.1mm Barrel Jack with Terminal Block. The Arduino UNO receives commands via Bluetooth and drives the motors to move the car forward, backward, turn left, turn right, or stop.

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.

Motor Amarillo Motorreductor Hobby (x2)

A yellow hobby gear motor
Operates on a voltage suitable for interfacing with the L298N motor driver.

Bluetooth HC-06

A wireless Bluetooth transceiver module
Allows serial communication over Bluetooth.

Battery 9V (x2)

Standard 9V batteries
Provide power to the motor driver and, indirectly, to the motors.

L298N DC Motor Driver

A dual H-bridge motor driver
Capable of driving two DC motors or one stepper motor.

2.1mm Barrel Jack with Terminal Block

A connector for attaching external power sources
Used to connect the 9V batteries to the circuit.

Wiring Details

Arduino UNO

5V connected to Bluetooth HC-06 VCC
GND connected to Bluetooth HC-06 GND
D7 connected to L298N DC motor driver IN1
D6 connected to L298N DC motor driver IN2
D5 connected to L298N DC motor driver IN3
D4 connected to L298N DC motor driver IN4
D1 (TX) connected to Bluetooth HC-06 RXD
D0 (RX) connected to Bluetooth HC-06 TXD

Motor Amarillo Motorreductor Hobby

vcc of the first motor connected to L298N DC motor driver OUT2
GND of the first motor connected to L298N DC motor driver OUT1
vcc of the second motor connected to L298N DC motor driver OUT4
GND of the second motor connected to L298N DC motor driver OUT3

Bluetooth HC-06

VCC connected to Arduino UNO 5V
GND connected to Arduino UNO GND
TXD connected to Arduino UNO D0 (RX)
RXD connected to Arduino UNO D1 (TX)

Battery 9V

VCC of the first battery connected to L298N DC motor driver 12V and 2.1mm Barrel Jack POS
GND of the first battery connected to 2.1mm Barrel Jack NEG
VCC of the second battery connected to L298N DC motor driver 12V
GND of the second battery connected to L298N DC motor driver GND

L298N DC Motor Driver

IN1 connected to Arduino UNO D7
IN2 connected to Arduino UNO D6
IN3 connected to Arduino UNO D5
IN4 connected to Arduino UNO D4
OUT1 connected to the first motor GND
OUT2 connected to the first motor vcc
OUT3 connected to the second motor GND
OUT4 connected to the second motor vcc
12V connected to both 9V batteries VCC
GND connected to the second 9V battery GND

2.1mm Barrel Jack with Terminal Block

POS connected to the first 9V battery VCC
NEG connected to the first 9V battery GND

Documented Code

/*
 * Arduino Sketch for controlling a car using Bluetooth technology.
 * This code reads commands from the Serial input (Bluetooth module) and
 * controls the car's movement accordingly. The car can move forward,
 * backward, turn left, turn right, and stop based on the received commands.
 */

int Input_Pin_4 = 4; // Connected to L298N IN4
int Input_Pin_3 = 5; // Connected to L298N IN3
int Input_Pin_2 = 6; // Connected to L298N IN2
int Input_Pin_1 = 7; // Connected to L298N IN1
char Value;

void setup() {
  pinMode(Input_Pin_4, OUTPUT);  // Digital pin 4
  pinMode(Input_Pin_3, OUTPUT);  // Digital pin 5
  pinMode(Input_Pin_2, OUTPUT);  // Digital pin 6
  pinMode(Input_Pin_1, OUTPUT);  // Digital pin 7
  Serial.begin(9600);
}

void loop() {
  while (Serial.available() > 0) {
    Value = Serial.read();
    Serial.println(Value);
  }
  if (Value == 'F') {
    // Move Forward
    digitalWrite(Input_Pin_1, HIGH);
    digitalWrite(Input_Pin_2, LOW);
    digitalWrite(Input_Pin_3, HIGH);
    digitalWrite(Input_Pin_4, LOW);
  } else if (Value == 'B') {
    // Move Backward
    digitalWrite(Input_Pin_1, LOW);
    digitalWrite(Input_Pin_2, HIGH);
    digitalWrite(Input_Pin_3, LOW);
    digitalWrite(Input_Pin_4, HIGH);
  } else if (Value == 'L') {
    // Turn Left
    digitalWrite(Input_Pin_1, LOW);
    digitalWrite(Input_Pin_2, LOW);
    digitalWrite(Input_Pin_3, HIGH);
    digitalWrite(Input_Pin_4, LOW);
  } else if (Value == 'R') {
    // Turn Right
    digitalWrite(Input_Pin_1, HIGH);
    digitalWrite(Input_Pin_2, LOW);
    digitalWrite(Input_Pin_3, LOW);
    digitalWrite(Input_Pin_4, LOW);
  } else if (Value == 'S') {
    // Stop
    digitalWrite(Input_Pin_1, LOW);
    digitalWrite(Input_Pin_2, LOW);
    digitalWrite(Input_Pin_3, LOW);
    digitalWrite(Input_Pin_4, LOW);
  }
}

This code is designed to be uploaded to the Arduino UNO microcontroller. It sets up the digital pins connected to the L298N motor driver as outputs and initializes serial communication for receiving Bluetooth commands. The loop function reads the incoming serial data and controls the motor driver to move the car based on the received command character.