Pin 1 : VSS is the ground power supply
Pin 2 : VDD Positive power supply connected to 5V
Pin 3 : V0 LCD contrast adjustment for the end , connected to the positive power supply weakest contrast , when the power is grounded highest contrast
Pin4 : RS for register selection , the selection of high data registers, low selection instruction register.
Pin 5 : R / W When the R / W and E are high , data is read DB0 ~ DB7; when R / W is low , E from high to low , DB0 ~ DB7 the data is written to IR or DR register .