// https://wokwi.com/projects/397870120127088641 

#include <LiquidCrystal.h>
LiquidCrystal lcd( 12, 13, 15, 16,  17, 18); 
                // RS, E, DB4, DB5, DB6, DB7
 
void Lcd( float temp, float rh, byte pos  ); 
void Seriell( float temp, float rh, byte pos ); 

#include "DHT.h"
#define nr_of_DHTs 2
DHT dht[] = {
  {4, DHT22},   // DHT dht1(4, DHT22);
  {7, DHT22}  };   // DHT dht2(7, DHT22);  // DHT 22  (AM2302), AM2321    3P

void setup() { // initialize serial interface, LCD + ports:
  Serial.begin( 9600 ) ;
  lcd.begin( 16,2 ) ;
  for( byte i = 0; i < nr_of_DHTs ; i++ ) dht[i].begin();   // 5P
}

void Lcd( float temp, float rh, byte pos  )
{         // Temp    RH        pos = 0 / 1 / 2 / 3
  if( pos > 4 ) pos %= 4;  
  lcd.setCursor(  0,pos ); 
  lcd.print( String(pos)+":" ); 
  lcd.print( temp,1 ) ; 
  lcd.write( 223 );  lcd.print( "C " ); 
  if( rh < 100 ) lcd.print(" "); 
  if( rh < 10)   lcd.print(" ");
  lcd.print( rh,1 ); lcd.print( "% " );                    // 10P
}

void Seriell( float temp, float rh, byte pos )
{
  Serial.print("DHT"+String(pos)+":" ); 
  Serial.print( temp,1 ) ; Serial.print( "°C \t"); 
  Serial.print( rh,1 ) ; Serial.println( "%   ");          // 5P
}

void loop() {  // ADW + ser.interface + LCD-output of Voltage
  static float temp[nr_of_DHTs], old_temp[nr_of_DHTs] = {88,88}; 
  static float humi[nr_of_DHTs], old_humi[nr_of_DHTs] = {-1,-1};
  static unsigned long lastTime = 0 ;
  if( millis() - lastTime > 1000 )
  {
    for( byte i = 0; i < nr_of_DHTs; i++ )
    {  
      temp[i] = dht[i].readTemperature(); 
      humi[i] = dht[i].readHumidity(); 
      Lcd( temp[i], humi[i], i); 
      if( abs( old_temp[i] - temp[i] ) > 2.0 ||
          abs( old_humi[i] - humi[i] ) > 2.0)
      { Seriell( temp[i], humi[i], i ); 
        old_temp[i] = temp[i] ; 
        old_humi[i] = humi[i] ; 
      }
    }  
    lastTime = millis();                                    // 17P
  }
}