const int tPin = 13;
const int ePin = 12;
const int gPin = 2;
const int bPin = 4;

#define S_VEL 0.034

#define CM2FT

long dTime;
float dCm;
float dft;

void setup(){
  serial.begain(115200);
  serial.bgain("ESP32 Ultrasonic Sensor Test");

  pinMode(tPin, OUTPUT);
  pinMode(ePin, INPUT);
  pinMode(gPin, OUTPUT);
  pinMode(bPin, OUTPUT);
}.

void loop(){
  digitalWrite(tPin, LOW);
  delayMicroseconds(10);

  if (dCm < 10) {
    
  }
}