#include <LiquidCrystal_I2C.h>

int Pir_sensor_pin = 34;         // Choose the input pin (for PIR sensor)
int ledPin = 25;                // Choose the pin for the LED
int pirState = LOW;             // We start, assuming no motion detected
int val = 0;                    // Variable for reading the pin status
int previousState = 0;          // Define Previous state
int counter = 0;                // Define Counter
#define I2C_ADDR    0x27        //LCD monitor I2C address (I2C configuration)
#define LCD_COLUMNS 16          //LCD monitor X axis columns = ?
#define LCD_LINES   2           //LCD monitor Y axis = ? 

LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES); //LCD part

void setup() {
     Serial.begin(115200);                 //Initialize Serial port
     lcd.begin(21, 22);                   //SDA = port D21 (data line) ,SCl = port D22 (clock time)
// you can now interact with the LCD, e.g.:
     pinMode(Pir_sensor_pin, INPUT);     // Declare sensor as input
     lcd.init();                        //Open LCD  SET
     lcd.backlight();                   //Open LCD backlight
     lcd.setBacklight(1);
     delay(1000);
     lcd.clear();
     lcd.setCursor(0, 0);
     lcd.print("Hello");           //Test LCD is work?
     lcd.setCursor(0, 1);  
     lcd.print("Sam Sir!");
     delay(2000);                        
     lcd.clear();                           //Clear LCD txt
     lcd.setCursor(0, 0);                  //Set LCD txt location in line top
     lcd.print("Group Project");          //LCD print txt
     lcd.setCursor(0, 1);                //Set LCD txt location in line down
     lcd.print("People Counter");
     delay(2000);                       //Delay 2sec (1000 = 1sec)
     lcd.clear();
     lcd.setCursor(0, 0);  
     lcd.print("Michael  Angie");
     lcd.setCursor(0, 1);
     lcd.print("Henry  Jacky");
     delay(2000);
     lcd.clear();  
     lcd.setCursor(0, 0);
     lcd.print("Please press ");
     lcd.setCursor(0, 1);
     lcd.print("PIR motion sensor ");
     delay(1500);
     lcd.clear(); 
     lcd.setCursor(0, 0);
     lcd.print("To simulation ");
     lcd.setCursor(0, 1);
     lcd.print("People trigger ");
     pinMode(ledPin, OUTPUT);      // declare LED as output
     pinMode(Pir_sensor_pin, INPUT);     // declare sensor as input
}

void loop() {
  val = digitalRead(Pir_sensor_pin);  // read input value
  if (val == HIGH) {            // check if the input is HIGH
    digitalWrite(ledPin, HIGH);  // turn LED ON
    if (pirState == LOW) {
// we have just use lcd output txt
      lcd.setCursor(0, 0);
      lcd.print("People Detected!");
      delay(2000);
      lcd.clear();
// We only want to print on the output change, not state
      pirState = HIGH;
   }
  } 
  else {
    digitalWrite(ledPin, LOW); // turn LED OFF
    if (pirState == HIGH) {
      // we have just turned of
      lcd.setCursor(0, 0);
      delay(2000);
// We only want to print on the output change, not state
      pirState = LOW;
    }
  }
//detect people in +1
          if(pirState != previousState){
          if(pirState == 1){
               counter = counter + 1;
               lcd.setCursor(0,0);
               lcd.print("People Count !");
               lcd.setCursor(0,1);
               lcd.print("= ");
               lcd.print(counter);
               delay(3000);
               }
      }
            
}