/* This is just a rudimentary code to *hopefully* attach to Marek's overall code. Using WOKWI, I as able
   to simulate and verify the function of it. This will indicate if the locker is full, empty, or open.
   Not sure how to implement a code to indicate that someone filled the locker but left it open, unless
   we use an additional sensor. But more sensors = more $$$. */
   
#define PIN_TRIG 2
#define PIN_ECHO 3
#define BLUE_LED 7
#define GREEN_LED 6
#define RED_LED 5

const int FULL_LOCKER = 10;   // Distance in CM when considered full.
const int EMPTY_LOCKER = 31;  // Distance in CM when considered empty.
const int OPEN_DOOR = 35;     // Distance in CM when considered open!

void setup() {
  pinMode(PIN_TRIG, OUTPUT);
  pinMode(PIN_ECHO, INPUT);
  pinMode(BLUE_LED, OUTPUT);
  pinMode(GREEN_LED, OUTPUT);
  pinMode(RED_LED, OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  long duration, distance;
  digitalWrite(PIN_TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(PIN_TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(PIN_TRIG, LOW);
  duration = pulseIn(PIN_ECHO, HIGH);
  distance = (duration / 2) / 29.1;

  /* Lets say that the distance between the sensor and the
    the compartment door is 12 inches. We could use an if/else
    statement that will light the green LED if the locker is empty,
    the red LED if the locker is full, and the blue LED if the door
    is open.
    */

  if (distance < FULL_LOCKER){
    digitalWrite(RED_LED, HIGH);
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(BLUE_LED, LOW);
  }
  else if (distance > OPEN_DOOR){
    digitalWrite(BLUE_LED, HIGH);
    digitalWrite(GREEN_LED, LOW);
    digitalWrite(RED_LED, LOW);
  }
  else if (distance == EMPTY_LOCKER){
    digitalWrite(GREEN_LED, HIGH);
    digitalWrite(BLUE_LED, LOW);
    digitalWrite(RED_LED, LOW);
  }
  
  Serial.print("Distance: ");             // Displays the distance in centimeters.
  Serial.print(distance);
  Serial.println(" cm");
  Serial.print("Distance in inches: ");  // Converts distance from centimeters to display in inches.
  Serial.print(distance / 2.54);
  Serial.println(" inches");

  delay(500); // Delay between measurements.
  
}