#include <LiquidCrystal_I2C.h>
#include <Servo.h> 
LiquidCrystal_I2C lcd(0x27,16,2); 
Servo Servo1;
const int servoPin = 3;




#include <NewPing.h> //this a library for ultrasound sensor
#define TRIGGER_level  6  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_level     7  // Arduino pin tied to echo pin on the ultrasonic sensor.
#define TRIGGER_lid  9  // Arduino pin tied to trigger pin on the ultrasonic sensor.
#define ECHO_lid    10  // Arduino pin tied to echo pin on the ultrasonic sensor.
NewPing level(TRIGGER_level, ECHO_level, 40); // NewPing setup of pins and maximum distance.
NewPing lid(TRIGGER_lid, ECHO_lid, 5); // NewPing setup of pins and maximum distance.
int lid_distance;//the distance measure by lid sensor is store in this variable
int level_distance_now=-1; // I have decleare two variable for it because it note changes in level if there is a change between prev and now value then it do some otherwise it will ignore every its function
int level_distance_prev=-3;// the values are arbitery any value can given but not should be equal so that first value can be detected


const int buzzer = 4; 
const int green_led=5;
const int white_led=11;
const int orange_led= 12;
const int red_led=13;


 
void setup() {
 
  Servo1.attach(servoPin); // just to inform the arduino that a servo motor is attached to this pin and then it should care of its related when its function is needed
  lcd_setup();
  pinMode(green_led, OUTPUT);
  pinMode(orange_led, OUTPUT);
  pinMode(white_led, OUTPUT);
  pinMode(red_led, OUTPUT);
  
}
void loop() 
{

  sensors_data();// just to gain updated data from both sensors now the variable lid_distance and level_distance_now  will have updated data after this function
  if((lid_distance<=5)&&(lid_distance>0))//this is the format of code of maths relation "0<distance<5".I have putted the zero because now the maximuim distance is 5 and if detected no thing then for value more than 5 will be consider 0 so we have put condition more than zero not a zero this also a problem to me to it continuesly detect garbish when no thing was there because value more than 5 is consider so and thus I solve this
    open_lid();
  if((level_distance_now-level_distance_prev>=2)||(level_distance_now-level_distance_prev<=-2))//this is for relation "a differnce of 2 cm has occur " I have keep this difference two cm because 1 cm can occur due to some envirmental change or by insect can come in its fornt so just to insure that a real change in level occur I put 2cm difference "|| pronounce as OR"
  level_related_function(); // if real change has occur then do this function other wise lcd should show no display
  else
  lcd.noDisplay(); 
}

void open_lid(){
   digitalWrite(green_led, HIGH);
   Servo1.write(150); 
   delay(10000); 
   digitalWrite(green_led, LOW);
     Servo1.write(0); 
   delay(500); 
}

void lcd_setup()
{
  lcd.init(); // the function nessary for lcd to become on
  lcd.clear();// if it has some prev writting then make sure it may not overwrite       
  lcd.backlight();      // Make sure backlight is on

}


void level_related_function() // the function which deals with change occur in level
{

 level_distance_prev=level_distance_now; // level_distance_prev has done its work now it should be updated
  if (level_distance_now>33)
 { 
   lcd.display(); // the lcd should  show writing   
   digitalWrite(orange_led, LOW);
    digitalWrite(red_led, LOW);
    digitalWrite(white_led, HIGH);// you do not need buzzer be low because it already low 
    lcd.setCursor(2,0);   //Set cursor to character 0 on line 0

    lcd.clear();
    lcd.print("Dustbin is");
    lcd.setCursor(3,1);
    lcd.print("20% FULL");
    delay(30000);
 }
  if ((20<level_distance_now)&&(33>level_distance_now))// code format for relation"20<level_distance_now<33" "&& can be pronounce as AND"
  {
     lcd.display();// lcd should show display
    digitalWrite(orange_led, HIGH);
    digitalWrite(red_led, LOW);
    digitalWrite(white_led, LOW);
    lcd.clear();// prev should not overwrite
    lcd.setCursor(2,0);   //Set cursor to character 0 on line 0
    lcd.print("Dustbin is");
    lcd.setCursor(3,1);
    lcd.print("50% FULL");
    delay(30000);

  }
  if ((8<level_distance_now)&&(20>level_distance_now))
  {
     lcd.display();
    digitalWrite(orange_led, LOW);
    digitalWrite(red_led, HIGH);
    digitalWrite(white_led, LOW);
    lcd.clear();
    lcd.setCursor(2,0);   //Set cursor to character 0 on line 0
    lcd.print("Dustbin is");
    lcd.setCursor(3,1);
    lcd.print("80% FULL");
    delay(30000);
  }
  if ((3<level_distance_now)&&(8>level_distance_now))
  {
     lcd.display();
    digitalWrite(orange_led, LOW);
    digitalWrite(red_led, HIGH);
    digitalWrite(white_led, LOW);
    digitalWrite(buzzer,HIGH);
    lcd.clear();
    lcd.setCursor(2,0);   //Set cursor to character 0 on line 0
    lcd.print("Dustbin is");
    lcd.setCursor(3,1);
    lcd.print("FULL");
    delay(30000);
    digitalWrite(buzzer,LOW);
  }

}


void sensors_data()
  {
  delay(50);   // wait for some time so that prev effects may stable
   level_distance_now=level.ping_cm();
  lid_distance=lid.ping_cm(); // lid.ping_cm() is the function to detect distance of lid in cm and then we assign it lid distance and from this line it lid_distance is updeted


  }