int green=21;
int red=18;
int motion=14;
int ldr=33;
int buzzer=19;

int motion_value=0;
int ldr_value=0;
int sonic_echo=27;
int sonic_trig=26;
int distance_threshold=250;

float duration_us, weight_g;

void setup() {
  
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");

  pinMode(green,OUTPUT);
  pinMode(red, OUTPUT);
  pinMode(motion, INPUT);
  pinMode(ldr, INPUT);
  pinMode(sonic_echo, INPUT);
  pinMode(sonic_trig, OUTPUT);
  pinMode(buzzer, OUTPUT);
}

void loop() {
  
  motion_value = digitalRead(motion);
  Serial.println("Motion value: "+ String(motion_value));
  ldr_value = analogRead(ldr);
  Serial.println("Ldr value: "+ String(ldr_value));

  // to sense motion
  motion_value = digitalRead(motion);
  if(motion_value==HIGH && ldr_value>=1001)
  {
    digitalWrite(green, HIGH);
  }
  else
  {
    digitalWrite(green, LOW);
  }

  //to sense coffee making
  if(green==HIGH)
  {
    digitalWrite(sonic_trig, HIGH);
    digitalWrite(sonic_echo, HIGH);
  }
  else
  {
    digitalWrite(sonic_trig, LOW);
    digitalWrite(sonic_echo, LOW);
  }

  //to sense Filled Cup
  
  digitalWrite(sonic_trig, HIGH);
  delayMicroseconds(15);
  digitalWrite(sonic_trig, LOW);

  duration_us = pulseIn(sonic_echo, HIGH);
  weight_g = 0.02 * duration_us;

  if (weight_g > distance_threshold)
  {
    digitalWrite(red, HIGH);
    tone(buzzer,200); // turn on LED
  }
  else
  {
    digitalWrite(red, LOW); 
    noTone(buzzer); // turn off LED
  }

  // print the value to Serial Monitor
  Serial.print("weight: ");
  Serial.print(weight_g);
  Serial.println(" g");

}

//in order for the green light to turn on, turn off the red light as to indicate that the coffee making process is starting and hasnt finished