#include <Ultrasonic.h>

#define echoPin 5 
#define trigPin 6
#define led1 9

Ultrasonic ultrasonic(6, 5);

void setup() {
  
Serial.begin(9600);
pinMode(led1, OUTPUT);

}

void loop() {

long dist;
dist = ultrasonic.read(CM);
Serial.print(dist);
Serial.println(" cm");

if (dist < 15)
{
  flashing_LED(led1, 500);
}

else if (dist > 80)
  digitalWrite(led1, HIGH);

else
  digitalWrite(led1, LOW);

delay(500);
}

void flashing_LED(int led_pin, int del){
  digitalWrite(led_pin, HIGH);
  delay(del);
  digitalWrite(led_pin, LOW);
}