How To Connect the I2C LCD to Arduino UNOĬonnecting the Arduino UNO to the I2C interface of the LCD requires only four connections. The connections include two for power and two for data. The chart below shows the connections needed. Once you have the four connections to your LCD made, you can power your Arduino, which will provide power to the LCD. The LCD has an adjustment on it which needs to be approximately set to allow you to see characters on the display. You must now adjust that contrast setting. Located on the back of the LCD screen is the I2C interface board, and on the interface is an adjustable potentiometer. This adjustment is made with a small screwdriver. You will adjust the potentiometer until a series of rectangles appear – this will allow you to see your programming results.Īfter you have your first program loaded, and you can see the output on the LCD, you can go back and adjust the contrast control for optimal viewing. The Arduino module and editor do not know how to communicate with the I2C interface on the LCD. The parameter to enable the Arduino to send commands to the LCD are in separately downloaded LiquidCrystal_I2C library.

The LiquidCrystal_I2C is available from GitHub. When visiting the GitHub page, select the Code button and from the drop-down menu, choose Download ZIP option to save the file to a convenient location on your workstation. We also have the LiquidCrystal_I2C library available for download directly on our site should the master GitHub repository ever disappear.

Tiny wire library