int t_p=4;
int e_p=16;
float ss=0.034;
long durn;
float dist_cm;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(t_p,OUTPUT);  // sent data
  pinMode(e_p,INPUT);  // reseive data
}

void loop() {
  digitalWrite(t_p,LOW);
  delayMicroseconds(2);
  digitalWrite(t_p,HIGH);
  delayMicroseconds(10);
  digitalWrite(t_p,LOW);
  durn=pulseIn(e_p,HIGH);
  dist_cm=durn*ss/2;
  Serial.print("distanc= ");
  Serial.print(dist_cm);
  Serial.print("\n");
    delay(1000);

}