The PCF8574 I2C Serial Interface Adapter Module is designed to simplify the connection of character LCD displays, such as 16×2 and 20×4 LCDs, to microcontrollers. It converts I2C serial communication into parallel signals, reducing the number of GPIO pins required for display interfacing.

Features

• Based on the PCF8574 I/O expander IC

• Supports I2C serial communication

• Reduces the number of microcontroller pins needed for LCD connections

• Compatible with many HD44780-compatible character LCDs

• Adjustable contrast using an onboard trimmer potentiometer

• LCD backlight control

• Selectable I2C address using A0, A1, and A2 connections

• Compact PCB design with a 4-pin I2C interface

Specifications

Pin Configuration

Applications

• 16×2 LCD display interfacing

• 20×4 LCD display interfacing

• Arduino projects

• ESP32 and other compatible microcontroller projects

• Sensor monitoring systems

• DIY electronic projects

• Embedded systems and display-based interfaces

Advantages

• Saves GPIO pins on the microcontroller

• Simplifies LCD wiring

• Provides convenient contrast adjustment

• Supports configurable I2C addressing

• Easy integration with common Arduino LCD libraries

• Reduces wiring complexity in compact projects

Package Includes

– 1 × PCF8574 I2C Serial Interface Adapter Module

Note

This module is commonly used with LCDs that have a compatible 16-pin parallel interface. Confirm the LCD pinout and module compatibility before installation. When using a 3.3V microcontroller such as an ESP32, verify the module’s I2C voltage levels and pull-up resistors to avoid exposing the GPIO pins to 5V.