// ---------------------------------------------------------------------------
// Example NewPing library sketch that does a ping about 20 times per second.
// ---------------------------------------------------------------------------

#include <NewPing.h>

#define TRIGGER_PIN  2  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_PIN     3  // Arduino pin tied to echo pin on the ultrasonic sensor.
#define MAX_DISTANCE 400 // Maximum distance we want to ping for (in centimeters). Maximum sensor distance is rated at 400-500cm.

NewPing sonar(TRIGGER_PIN, ECHO_PIN, MAX_DISTANCE); // NewPing setup of pins and maximum distance.

void setup() {
  Serial.begin(115200); // Open serial monitor at 115200 baud to see ping results.
  pinMode(4, OUTPUT);
  pinMode(5, OUTPUT);
  pinMode(6, OUTPUT);
  pinMode(7, OUTPUT);    
}
void loop() {
  int sonar1;
  delay(50);           // Wait 50ms between pings (about 20 pings/sec). 29ms should be the shortest delay between pings.
  sonar1=sonar.ping_cm();
  Serial.print("Ping: ");
  Serial.print(sonar1); // Send ping, get distance in cm and print result (0 = outside set distance range)
  Serial.println("cm");

  if(sonar1>100){
    digitalWrite(4, LOW);
    digitalWrite(5, LOW);
    digitalWrite(6, LOW);
    digitalWrite(7, LOW);            
  } else {
    if(sonar1<=100 and sonar1>60){
      digitalWrite(4, LOW);
      digitalWrite(5, LOW);
      digitalWrite(6, HIGH);
      digitalWrite(7, LOW);
    } else{
      if(sonar1<=60 and sonar1>30){
      digitalWrite(4, LOW);
      digitalWrite(5, HIGH);
      digitalWrite(6, LOW);
      digitalWrite(7, LOW);
      } else{
        if(sonar1<30){
        digitalWrite(4, HIGH);
        digitalWrite(5, LOW);
        digitalWrite(6, LOW);
        digitalWrite(7, HIGH); delay(500); digitalWrite(4, LOW);
        }
      }
      delay(500);
      digitalWrite(7, LOW);
      delay(500);
    }
  }
}