LCD1602 Module

Generally, LCD1602 has parallel ports, that is, it would control several pins at the same time. LCD1602 can be categorized into eight-port and four-port connections. If the eight-port connection is used, then all the digital ports of the SunFounder Uno board are almost completely occupied. If you want to connect more sensors, there will be no ports available. Therefore, the four-port connection is used here for better application.
Pins of LCD1602 and their functions
VSS: connected to ground
VDD: connected to a +5V power supply
VO: to adjust the contrast
RS: A register select pin that controls where in the LCD’s memory you are writing data to. You can select either the data register, which holds what goes on the screen, or an instruction register, which is where the LCD’s controller looks for instructions on what to do next.
R/W: A Read/Write pin to select between reading and writing mode
E: An enabling pin that, when low-level energy is supplied, causes the LDC module to execute relevant instructions.
D0-D7: to read and write data
A and K: Pins that control the LCD backlight