#include <DHT22.h>               
#include <Wire.h>                
#include <LiquidCrystal_I2C.h>   

DHT22 dht1(2);  
DHT22 dht2(3);
DHT22 dht3(4);

int switch1State = 0;
int switch2State = 0;

LiquidCrystal_I2C lcd(0x27, 16, 2);  
void setup() {
  Serial.begin(9600);
  lcd.init();  
  lcd.backlight();
  pinMode(9, INPUT_PULLUP);//Switch 
  pinMode(10, INPUT_PULLUP);
  pinMode(11, OUTPUT);//LED
  pinMode(12, OUTPUT);
  pinMode(13, OUTPUT);
}

void loop() {
  float temperature1 = dht1.getTemperature();   
  float temperature2 = dht2.getTemperature();  
  float temperature3 = dht3.getTemperature();
  float avg = (temperature1 + temperature2 + temperature3)/3 ;  

  delay(2000);
  Serial.println("Temp1 : " + String(temperature1) + " C"); 
  Serial.println("Temp2 : " + String(temperature2) + " C");
  Serial.println("Temp3 : " + String(temperature3) + " C");
  Serial.println("avg : " + String(avg) + " C");  

  switch1State = digitalRead(9);
  if (switch1State == LOW) {
    lcd.clear();  
    lcd.setCursor(0, 0);
    digitalWrite(13, LOW);
    digitalWrite(12, LOW);
    digitalWrite(11, HIGH);
    lcd.print("Temp1: ");  
    lcd.print(temperature1);  
    lcd.print(" C");
    delay(1500);
  }
  switch1State = digitalRead(9);
  if (switch1State == LOW) {
    lcd.clear();  
    lcd.setCursor(0, 0);
    digitalWrite(11, LOW);
    digitalWrite(13, LOW);
    digitalWrite(12, HIGH);  
    lcd.print("Temp2: ");  
    lcd.print(temperature2);  
    lcd.print(" C");  
    delay(1500);
  }  
  switch1State = digitalRead(9);
  if (switch1State == LOW) {
    lcd.clear();  
    lcd.setCursor(0, 0); 
    digitalWrite(11, LOW);
    digitalWrite(12, LOW);
    digitalWrite(13, HIGH); 
    lcd.print("Temp3: ");  
    lcd.print(temperature3);  
    lcd.print(" C");  
  }  
  switch2State = digitalRead(10);
  if (switch2State == LOW) {
    lcd.clear();  
    lcd.setCursor(0, 0); 
    digitalWrite(11, LOW);
    digitalWrite(12, LOW);
    digitalWrite(13, LOW);  
    lcd.print("avg: "); 
    lcd.print(avg);
    lcd.print(" C");
    delay(1500);
  }
}