PCF8574 I2C Serial Interface Adapter Module for 1602 & 2004 LCD Displays

The PCF8574 I2C Serial Interface Adapter converts the 16‑pin parallel connection of common character displays into a two‑wire I2C interface, letting you drive 1602 (16x2) and 2004 (20x4) modules with just SDA and SCL. Often called an “LCD backpack,” it solders to the display header and includes an onboard potentiometer for easy contrast tuning. Use the A0/A1/A2 solder pads to change the I2C address (default 0x27 or 0x3F) so multiple screens can share one bus, and remove the backlight jumper cap to disable the LED backlight for lower power when needed. Practical for Arduino and other microcontroller projects, this adapter preserves GPIO for sensors and actuators while simplifying wiring and setup; saves I/O pins and makes integration straightforward.