Temperature and Humidity sensor using Arduino display on I2C 16X2 LCD    Library download link  -  https://bitbucket.org/fmalpartida/new-liquidcrystal/downloads     NOTE:  Some of this type board come with the A0 A1 A2 connections (See photo) that are NOT bridged with solder as in the photo. Those will have address 0x27 not address 0x20. For that version you need to change the sketch example below.     LiquidCrystal_I2C lcd(0x20, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); MUST BE CHANGED TO: LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE);         Completed project           Schematics         A quick video       Code -     #include <dht.h>   #include <Wire.h>   #include <LCD.h>   #include <LiquidCrystal_I2C.h>   LiquidCrystal_I2C lcd(0x20, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Addr, En, Rw, Rs, d4, d5, d6, d7, backlighpin, polarity     #define dht_dpin A0 //no ; here. Set equal to channel sensor is on     dht DHT;     void setup(){     Ser...