I2C LCD Interface Module – Serial Adapter for 16×2 and 20×4 Character LCDs The I2C LCD Interface Module is a compact adapter board that enables I2C communication with standard HD44780-based character LCDs (16×2, 20×4, etc.). It drastically reduces the number of pins required to control the LCD from a microcontroller, using only two data lines (SCL and SDA) instead of the usual 6–8 pins. Featuring a PCF8574 I/O expander, this module is ideal for Arduino, ESP32, STM32, and Raspberry Pi projects where GPIO pins are limited or optimization is required. Product Specifications Feature Specification Module Name I2C LCD Interface Module Chipset PCF8574 (I²C to 8-bit GPIO Expander) Input Voltage 5V (logic high) Interface I²C (SDA, SCL) I2C Address Default: 0x27 (configurable via jumpers) Compatible Displays 16×2, 20×4 Character LCDs with HD44780 Controller Contrast Adjustment Onboard potentiometer for LCD contrast tuning Backlight Control Software-controllable (via jumper and code) Dimensions Approx. 41mm x 20mm Key Features Reduces Pin UsageReplaces parallel communication with serial I²C, using only two microcontroller pins. Plug-and-Play CompatibilityEasily connects to LCDs using standard 16-pin headers. Onboard Contrast ControlBuilt-in potentiometer allows quick visual tuning of display contrast. Adjustable I2C AddressAddress selection jumpers allow multiple displays on the same I2C bus. Backlight ControlEnable or disable the LCD backlight through code or jumper settings. Benefits Simplifies WiringSignificantly cuts down on jumper wires in breadboard or PCB designs. GPIO OptimizationFrees up valuable I/O pins for other sensors, buttons, or peripherals. Arduino & ESP CompatibleSupported by popular libraries like LiquidCrystal_I2C, making integration fast and easy. Ideal for Compact ProjectsSuitable for space-constrained or portable designs where pin count and wiring are critical. Applications Microcontroller Display SystemsShow sensor data, menu interfaces, and system status messages. IoT Devices and DashboardsDisplay real-time telemetry, alerts, and connectivity info. Robotics InterfacesUse in robot control panels or onboard display units. DIY Electronics ProjectsIntegrate into smart gadgets, clocks, battery monitors, and more. Educational and STEM KitsGreat for teaching embedded system displays and I²C protocol basics.
