It's a IIC/I2C Serial Interface Adapter Module The blue preset is to adjust the contrast of the LCD. The black jumper on the left is to enable the Backlight of LCD. The I2C device has a HEX address by which a microcontroller can communicate with it. This is set by the 3 bits A0,A1 ,A2 .If no jumper is present , it is HIGH & a jumper means LOW. By default all the 3 jumpers are open. Modules, LCD Display Module, LCD Interface, Interface Module, I2C GPIO Expander Module.
Specification-
Supply voltage | 5v |
I2c address | 0x20~0x27 |
Country of Origin | China |