int t = 2;
int e = 3;
void setup()
{
  Serial.begin(9600);
  pinMode(t,OUTPUT);
  pinMode(e, INPUT);
}
void loop()
{
  digitalWrite(t,LOW);
  digitalWrite(t, HIGH);
  delayMicroseconds(10);
  digitalWrite(t,LOW);
  float dur = pulseIn(e,HIGH);
  float dis = (dur * 0.0343)/2;
  Serial.print("Distance in cm:");
  Serial.println((dis));
}