PCF8574 LCD to I2C Adapter Board

Simplify your character LCD wiring with this PCF8574-based I2C Adapter Board, commonly known as an “LCD backpack.” It converts the bulky 16-pin parallel interface used by standard 1602 (16×2) and 2004 (20×4) character LCD modules into a simple two-wire I2C connection, letting you drive a full display using only SDA and SCL. This frees up valuable GPIO pins for sensors, buttons, and other peripherals in your project.

Designed to solder directly onto the rear header of compatible LCD modules, this adapter is a favorite among hobbyists for its plug-and-play convenience. An onboard potentiometer allows quick, screwdriver-adjustable contrast tuning without needing extra components, while solder pads for A0, A1, and A2 let you change the I2C address so multiple displays can share the same bus, up to eight in a cascade. A removable jumper cap gives you control over the backlight power, useful for reducing consumption in battery-powered builds.

Compatible with Arduino, ESP32, ESP8266, Raspberry Pi, STM32, and other popular microcontroller platforms, this adapter is an essential, low-cost component for anyone building menu systems, sensor dashboards, or status displays with 1602 or 2004 LCDs.

Specification:

• IC Chip : PCF8574 / PCF8574T
• Compatible Displays : 1602 (16×2) & 2004 (20×4) LCD Modules
• Communication Interface : I2C (SDA, SCL)
• I2C Address : 0x20 to 0x27 (jumper selectable)
• Operating Voltage : 2.5V to 6V
• Contrast Adjustment : Onboard potentiometer
• Dimensions : Approx. 41.5mm x 19mm x 15.3mm