Very simple programmatic control of contrast and back light of an 1602 LCD display with Arduino
The code is part of my instructional video on how the 1602 display can be controlled:
Schematic: https://easyeda.com/bkolicoski/Low-pass-RC-filter-for-1602-LCD-contrast-adjustment
Instractable: https://www.instructables.com/id/1602-LCD-Contrast-Control-From-Arduino/