a little change in the init lines:
LiquidCrystal_I2C lcd(0x20, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Addr, En, Rw, Rs, d4, d5, d6, d7, backlighpin, polarity
It is another great blue backlight LCD display. As the pin resources of Arduino controller is limited, your project may be not able to use normal LCD shield after connected with a certain quantity of sensors or SD card. However, with this I2C interface LCD module, you will be able to realize data display via only 2 wires. If you already has I2C devices in your project, this LCD module actually cost no more resources at all. It is fantastic for Arduino based project.
I2C Address: 0x27 ( addres can't be changed !!!).
Backlight ( White character on Blue background)
Supply voltage: 5V
Size: 82x35x18 mm
Come with IIC interface, which can be connected by DuPont Line
1PCS IIC/I2C/TWI/SPI Serial Interface1602 16X2 LCD Module Display