int t1 = 19;
int e1 = 16;
int led = 25;
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  pinMode(t1, OUTPUT);
  pinMode(e1, INPUT);
  pinMode(led, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  digitalWrite(t1, HIGH);
  delay(500);
  digitalWrite(t1, LOW);
  int input = pulseIn(e1,HIGH);
  int output = input*0.034/2;
  Serial.println(output);
  if(output > 150)
  {
    digitalWrite(led, HIGH);
  }
  else { digitalWrite(led, LOW); }
  delay(10); // this speeds up the simulation
}