#include <LiquidCrystal_I2C.h>
#include <WiFi.h>

#define  LED_PIN 2
#define I2C_ADDR 0x27
#define LCD_COLUMNS 20
#define LCD_LINES 4
#define MOTION_PIN 23
#define TEM_PIN 15
#define BETA 3950

//some GPIO pin dont support analog signal!!

//declare LCD device
LiquidCrystal_I2C lcd(I2C_ADDR, LCD_COLUMNS, LCD_LINES);

int motion_val;//motion output   defualt:0
float tem_val;
int analog_val;

int recordCount = 0;
int temSum = 0 ;
int averTem = 0;  //Used to record the set of temperature when motion.

int OffCount = 0; //Calculate the low motion times;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(LED_PIN , OUTPUT);
  
  pinMode(MOTION_PIN , INPUT);

  pinMode(TEM_PIN , INPUT);

  WifiInitial();

  lcd.init();
  lcd.backlight();

}

void WifiInitial(void){
  WiFi.begin("Wokwi-GUEST", "", 6);
  while (WiFi.status() != WL_CONNECTED) {
    delay(100);
    Serial.print(".");
  }
  Serial.println(" Connected!");
}

void LCD_temperature(int number){
  lcd.setCursor(0 , 0);
  lcd.print("Temperature:");
  lcd.setCursor(8 , 1);
  lcd.print(number);
  lcd.print(" Celsius");
}

void temAndled(int tem_val){
    Serial.print("Temperature: ");
    Serial.print(tem_val);
    Serial.println("");
  if(tem_val <= 10){
    Serial.print("LED : ON\n");
}
  else Serial.print("LED : OFF\n");
}

void loop() {
// check whether output of motion sensor.
motion_val  = digitalRead(MOTION_PIN);
if(motion_val == HIGH){
  /*
  When a motion is detected, keep reading the temperature 
  from the temperature sensor and print the temperature on 
  the LCD display. 
  */
  OffCount = 0 ; //if motion is high, the count should restart

  analog_val = analogRead(TEM_PIN);
  tem_val = 1 / (log(1 / (4095. / analog_val - 1)) / BETA + 1.0 / 298.15) - 273.15;

  recordCount ++; //Temperature record count.
  temSum += tem_val;//Record the temperature.
  lcd.setCursor(0,2);
  lcd.print("Average: ");
  lcd.print(temSum / recordCount);

  LCD_temperature(tem_val);

  temAndled( tem_val);//Print out the temperature value and LED status through Serial.

  if(tem_val <= 10){
    /*If the temperature is below 10 ℃ when a motion is detected,
      turn on LED and print the “LED On” on the LCD display.*/
    digitalWrite(LED_PIN , HIGH);
    
    lcd.setCursor(6 , 3);
    lcd.print("LED ON");
  }
  else{
    /*When the OUT pin of the motion sensor goes LOW, turn off LED and 
     clean the LCD display. */
    digitalWrite(LED_PIN , LOW);
    lcd.clear();
    LCD_temperature(tem_val);
  }
  delay(500);   // Set the interval for reading data from the temperature sensor to 0.5 seconds. 
}
else{
    /*If the OUT pin of the motion sensor goes low, set the time interval 
    for reading data from the temperature sensor to 3 seconds.*/
    recordCount = 0 ; //Temperature record count.
    temSum = 0;//Record the temperature.
    delay(3000);   
    OffCount ++;
}   
if(OffCount >= 3)
    {
    digitalWrite(LED_PIN , LOW);
    lcd.clear();
    }

}