LCD1602 (yellow-green screen) Standard 16X2 LCD character module (backlight / yellow-green) 1602 standard 16-pin interface, including: VSS is the ground power, VDD then 5V positive power supply. V0 LCD contrast adjustment end, then the positive power supply when the contrast is the weakest, the highest contrast when grounded power, the contrast is too high will have a "ghosting", when used by a 10K potentiometer to adjust the contrast. RS for the register selection, high-level data register selection, low-level instruction register selection. https://www.campuscomponent.com/products/16x2-s-lcd-blue-backlight-lc-535-d/2208614000001842501