Default address: 0 x 27 for PCF8574T chip; 0 x 3F for PCF8574AT chip; Please kindly check the chip of the i2c interface; (Please remember to download the LiquidCrystal I2C library on GitHub before uploading the code to the control board)Compatibility: LCD display module is compatible for Arduino and Raspberry pi; It's working voltage is 5V and equipped with potentiometer to adjust backlight and contrastEasy to work: small I2C interface module can work very well; It only needs 2 signal connections, each of which requires a power supply and ground wire; A good circuit can reduce the number of connections between MCU and LCD; The 1602 LCD, each line displays 16 characters, a total of 2 lines, parallel interface, small in size, low power consumption and easy display operationIIC interface adapter: support IIC protocol, the kit contains an IIC / I2C serial interface adapter, no need to purchase an additional adapter, only two I/O ports, saving more space for other purposes, so you can call it directlyWide applications: LCD display with I2C serial interface can be applied to display characters, letters and numbers, real-time clocks, temperature, humidity, suitable for copiers, fax machines, industrial testing equipment, and network equipment such as routers and storage devicesColour:Photo ColorMaterial:Plastic + MetalPackage Contents:8 x 1602 LCD display modules8 x IIC / I2C serial interface adaptersOnly the above package content, other products are not included.Note: Light shooting and different displays may cause the color of the item in the picture a little different from the real thing. The measurement allowed error is +/- 1-3cm.