This is a brand-new design, uses MCP23017 chip, it is compatible with 1602 and 12864 liquid crystal screens, through this module is switched, use I2C communication, only need two MCU I/Os to be able to realize the liquid crystal to drive the display. The potentiometer on the module can achieve contrast adjustment. You can also unplug the jump cap to turn off the backlight or adjust the brightness through PWM. We provide wiring diagram and for arduino sample code.