I2C LCD Modules 16x2 and 20x4
Both modules operate and connect in the same way
Includes a ready-fitted I2C Module (backpack)
Use the potentiometer on rear to adjust contrast
Same wiring for both 2-line and 4-line displays
Only 2 data pins are required 
Close-up of LCD Wiring
  1. 5V on Arduino to VCC on I2C backpack
  2. Gnd on Arduino to GND on I2C backpack
  3. A5 on Arduino to SCL on I2C backpack
  4. A4 on Arduino to SDA on I2C backpack

  1. Install the library files from HERE
  2. Load the demonstration sketch from below to test out the connections:
    1. 16x2 Module
    2. 20x4 Module