/**********************************
*Project        : CoEIS Symposium – IoT contest
*Institution    : DeVry University
*Example        : Reading Sensor
*Program Purpose: Demonstrating Reading Sensor
*Date created   : 2024.06.11
**********************************/
// Define alias for Trig and Echo ports
#define Trig 26
#define Echo 25

const double speedOfSoundInAir = 343.; //Speed of sound used for th edistance calculation

long int pulseTime;
float distance;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
 
  pinMode(Trig, OUTPUT); // Configure the trigger pin as output. We will use this pin to send out ultrasonic burst
  pinMode(Echo, INPUT);// Configure the echo pin as input. We will use this pin to read the pulse coming back from the ultrasonic sensor


}

void loop() {

  //Sends a beep towards an obstacle and measures the time it takes for the beep to return back. 
  digitalWrite(Trig, LOW);
  delayMicroseconds(5);
  digitalWrite(Trig, HIGH);
  delayMicroseconds(10);
  digitalWrite(Trig, LOW);
  pulseTime = pulseIn(Echo, HIGH, 35000);

  // Use the pulseTime in microseconds to calculate the distance. 
  distance = double(pulseTime) * speedOfSoundInAir * 1.e-4 / 2.;//Calculates the distance in cm. 
  Serial.print(F("Sensor Distance: "));
  Serial.print(String(distance, 1));
  Serial.println(F("cm"));
  delay(2000); // this speeds up the simulation
}