int t=2;
int e=3;
void setup() {
  // put your setup code here, to run once:
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);  // put your main code here, to run repeatedly:

}