int t=2;
int e=4;
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);
}