Atmega328 UNO BOT

/*
* Project name:
Atmega328 UNO BOT
* Copyright
(c) Researchdesignlab.com
* Description:

* Test configuration:
MCU: ATMEGA328
Dev.Board: Arduino uno
Oscillator: 16 MHz
Software: Arduino

*/

int ENA=9; //Connect on Pin 9
int IN1=4; //Connect on Pin 4
int IN2=5; //Connect on Pin 5
int ENB=10; //Connect on Pin 10
int IN3=6; //Connect on Pin 6
int IN4=7; //Connect on Pin 7
int FR1=2; // front left fire sensor
int FR2=3; //front right fire sensor
int fan=8;
int ir1=A2; //back right ir
int ir2=A3; //front right ir
int ir3=A4; //front left ir
int ir4=A5; //back left ir
int i;

void setup()
{

Serial.begin(9600);
pinMode(ENA,OUTPUT);
pinMode(ENB,OUTPUT);
pinMode(IN1,OUTPUT);
pinMode(IN2,OUTPUT);
pinMode(IN3,OUTPUT);
pinMode(IN4,OUTPUT);
pinMode(FR1,INPUT);
pinMode(FR2,INPUT);

pinMode(ir1,INPUT);pinMode(ir2,INPUT);pinMode(ir3,INPUT);pinMode(ir4,INPUT);
pinMode(fan,OUTPUT);
digitalWrite(ENA,HIGH);// Activate motor A
digitalWrite(ENB,HIGH);// Activate motor B
}

void loop()
{
delay(1000);
if(digitalRead(ir2)==0)
{

digitalWrite(IN1,LOW);
digitalWrite(IN2,HIGH);
digitalWrite(IN3,HIGH);
digitalWrite(IN4,LOW);
delay(1000);

}
else if (digitalRead(ir3)==0)
{

digitalWrite(IN1,HIGH);
digitalWrite(IN2,LOW);
digitalWrite(IN3,LOW);
digitalWrite(IN4,HIGH);
delay(1000);
}
else if ((digitalRead(ir3)==0) && (digitalRead(ir2)==0))
{
digitalWrite(IN1,LOW);
digitalWrite(IN2,HIGH);
digitalWrite(IN3,LOW);
digitalWrite(IN4,HIGH);
delay(1000);
}
else
{
digitalWrite(IN1,HIGH);
digitalWrite(IN2,LOW);
digitalWrite(IN3,HIGH);
digitalWrite(IN4,LOW);
}
}