// #define TRIG_A_PIN 14 //  TRIG pin ultrasonic sensor A
// #define ECHO_A_PIN 12 //  ECHO pin
// #define LED 2

// float duration_a, distance_a, limit_a; // ultrasonic sensor A 

// // conter of repeats getting initial distance values
// int  counter_a, counter_b,counter_max;

// void setup() {
//    // begin serial port
//   Serial.begin (9600);

//   // configure the trigger pin to output mode
//   pinMode(TRIG_A_PIN, OUTPUT);
//  // configure the echo pin to input mode
//   pinMode(ECHO_A_PIN, INPUT);

//   counter_a = 0;
//   //distance to compare measured value -> lower value puts led on
//   limit_a = 30;
//   counter_max = 2;

//   pinMode(LED, OUTPUT);
// }

//////////////////////////////////////////////////////////
#define TRIG_PIN  13 // ESP32 pin GIOP26 connected to Ultrasonic Sensor's TRIG pin
#define ECHO_PIN  12 // ESP32 pin GIOP25 connected to Ultrasonic Sensor's ECHO pin
#define LED_PIN   2 // ESP32 pin GIOP17 connected to LED's pin
#define DISTANCE_THRESHOLD 200 // centimeters

// //define sound speed in cm/uS
#define SOUND_SPEED 0.034    
#define CM_TO_INCH 0.393701 

// variables will change:
float duration_us, distance_cm;

long duration;
float distance_Cm;
float distance_Inch;

void setup() {
  Serial.begin (9600);       // initialize serial port
  pinMode(TRIG_PIN, OUTPUT); // set ESP32 pin to output mode
  pinMode(ECHO_PIN, INPUT);  // set ESP32 pin to input mode
  pinMode(LED_PIN, OUTPUT);  // set ESP32 pin to output mode
}

void loop() {
  // generate 10-microsecond pulse to TRIG pin
  digitalWrite(TRIG_PIN, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG_PIN, LOW);

  // measure duration of pulse from ECHO pin
  duration = pulseIn(ECHO_PIN, HIGH);
  
  // Calculate the distance
  distance_Cm = duration * SOUND_SPEED/2;
  
  // Convert to inches
  distance_Inch = distance_Cm * CM_TO_INCH;
  
  // calculate the distance
  // distance_cm = 0.017 * duration_us;

  if (distance_Cm < DISTANCE_THRESHOLD) {
    digitalWrite(LED_PIN, HIGH); // turn on LED
    Serial.println("Bak Sampah Tidak Full");
    Serial.print("\nDistance (cm): ");
    Serial.println(distance_Cm);
    Serial.print("Distance (inch): ");
    Serial.println(distance_Inch);
    // delay(500);
  } else {
    digitalWrite(LED_PIN, LOW);  // turn off LED
    Serial.println("Bak Sampah Full!!!");
    Serial.print("\nDistance (cm): ");
    Serial.println(distance_Cm);
    Serial.print("Distance (inch): ");
    Serial.println(distance_Inch);
    // delay(500);
  }
  // Prints the distance in the Serial Monitor
  // Serial.print("\nDistance (cm): ");
  // Serial.println(distance_Cm);
  // Serial.print("Distance (inch): ");
  // Serial.println(distance_Inch);

  delay(500);
}