**2.4 I2C (inter integrated circuit) module and LCD 16×2**

I2C liquid crystal display (LCD) is an LCD module that is controlled serially synchronously with the I2C/IIC (inter-integrated circuit) or TWI (two wire interface) protocol. The figure of I2C is shown in **Figure 3**. The LCD module is controlled in parallel for both the data and control lines. However, parallel lines will take up a lot of pins on the controller side, so an I2C is needed to save on PIN usage on Arduino. The Arduino is supported I2C. The I2C pin is on pin A4 for serial data and pins A5 for serial clock. The pins between the Arduino and the I2C module are GND to ground, VCC to 5 V, SCL to A5 pin, and SDA to A4 pin from Arduino.
