int trigPin=7;
int echoPin=6;
int ledPin=5;
int buzzPin=4;
int dms=100;

int dt=250;

int pingTime;
float pingDist;
float actualDist;

void setup() {
  // put your setup code here, to run once:
pinMode (trigPin,OUTPUT);
pinMode (echoPin,INPUT);
pinMode (ledPin,OUTPUT);
pinMode (buzzPin,OUTPUT);

Serial.begin (9600);

}

void loop() {
  // put your main code here, to run repeatedly:
digitalWrite (trigPin,LOW);
delayMicroseconds(10);
digitalWrite (trigPin,HIGH);
delayMicroseconds (10);
digitalWrite(trigPin,LOW);
pingTime = pulseIn(echoPin,HIGH);
pingDist = (34./100000.) * pingTime;
actualDist = pingDist/2;
Serial.println(actualDist);
delay (dt);
if (actualDist <= 0.20) {
  digitalWrite (ledPin,HIGH);

  digitalWrite (buzzPin,HIGH);
  delayMicroseconds (dms);
  digitalWrite (buzzPin,LOW);
  delayMicroseconds (dms);
  digitalWrite (buzzPin,HIGH);
  delayMicroseconds (dms);
  digitalWrite (buzzPin,LOW);
  delayMicroseconds (dms);




}
else {
  digitalWrite (ledPin,LOW);
  digitalWrite (buzzPin,LOW);
}
}