/* Program for Smart Blind Stick  */ 
#include <LiquidCrystal_I2C.h> //includes LiquidCrystal_I2C library
LiquidCrystal_I2C lcd(0x27, 20, 4);
int trigPin1 = 4; 
int echoPin1 = 5; 
int buzzer = 7; 
long duration1; 
int distance1; 

void setup() 
{ 
   pinMode(trigPin1, OUTPUT); 
   pinMode(echoPin1, INPUT); 
   pinMode(buzzer, OUTPUT); 
   Serial.begin(9600); 
}

void loop() 
{ 
   digitalWrite(trigPin1, LOW); 
   delayMicroseconds(5); 
   digitalWrite(trigPin1, HIGH); 
   delayMicroseconds(15); 
   digitalWrite(trigPin1, LOW);
   duration1 = pulseIn(echoPin1, HIGH); 
   distance1= (duration1/2)*0.034;

   if (distance1 <= 100)
   { 
      tone(buzzer,3000); 
      delay(100);
      noTone(buzzer);
      delay(100);
      tone(buzzer,3000); 
      delay(100);
      noTone(buzzer);
      delay(100);
      lcd.init();
      lcd.backlight();
      lcd.setCursor (0,0);
      lcd.print("Object detected");
      delay (1000);
      lcd.clear();
   } 
   else
   { 
      noTone(buzzer); 
   }  
}