Arduino sensors connection Arduino 1 (DHT11, Rele, Pir, Buzzer, RFID, LEDS) - DHT11: PIN: 4, 5V - BUZZER: PIN: 33 - RELE: PIN: 27 5V - LCD: PIN: SS: 5 // RST: 2 5V - LED GREEN: PIN: 26 - LEED RED: PIN: 25 - PIR: PIN: 12 5V Arduino 2 (LEDS, )