This I²C Serial Interface Adapter Module revolutionizes how you connect standard 16×2 character LCD displays to microcontrollers by converting the traditional parallel interface to a simple I²C serial connection. Built around the PCF8574(T) I/O expander chip, this module dramatically reduces wiring complexity while maintaining full functionality of your HD44780-compatible LCD.
Core Module Specifications
Compatible LCDs: 16×2 (1602) and 20×4 character LCDs with HD44780 controller
Interface Converter: PCF8574 or PCF8574A I²C I/O expander chip
I²C Address Range: 0x20-0x27 (PCF8574) or 0x38-0x3F (PCF8574A)
Operating Voltage: 5V DC (compatible with 3.3V logic levels)
Backlight Control: Supported (jumper selectable)
Contrast Adjustment: Onboard potentiometer
Connection Specifications
I²C Interface:
SDA (Serial Data)
SCL (Serial Clock)
VCC (5V)
GND
LCD Interface: 16-pin header (compatible with standard HD44780 pinout)
Default I²C Address: Typically 0x27 or 0x3F (configurable via solder jumpers)
Physical Characteristics
Module Dimensions: Approximately 36mm × 45mm × 12mm
Mounting: 4x M2.5 mounting holes
Pin Spacing: Standard 2.54mm (0.1") pitch
Performance Features
Reduced Wiring: Converts 16 LCD pins to 4-wire I²C interface
Baud Rate: Standard 100kHz I²C (up to 400kHz in fast mode)
Backlight Current: ~20mA (when enabled)
Key Advantages
✔ Wiring Simplification: Reduces connection from 16+ wires to just 4 (VCC, GND, SDA, SCL)
✔ Plug-and-Play Compatibility: Works with Arduino, Raspberry Pi, ESP8266, and ESP32
✔ Address Configuration: Supports multiple I²C addresses for using several LCDs on one bus
✔ Integrated Features: Includes contrast potentiometer and backlight control
Technical Implementation
PCF8574 Chip: Acts as an I²C-to-parallel converter, emulating the HD44780 interface
Voltage Compatibility: 5V operation with 3.3V logic level tolerance
Backlight Management: Can be controlled via I²C commands or hardware jumper
Installation & Usage
Module Attachment: Solder directly to LCD or use male/female headers
I²C Address Selection: Configure via solder jumpers (A0-A2) if needed
Contrast Adjustment: Set using the blue potentiometer before first use
Library Support: Compatible with popular LiquidCrystal_I2C libraries
Application Scenarios
Arduino Projects: Save precious GPIO pins for other components
Raspberry Pi Systems: Connect LCDs without consuming multiple GPIOs
ESP8266/ESP32 IoT Devices: Maintain WiFi/BLE functionality while displaying data
Industrial Control Panels: Simplify wiring in control systems
Why Choose This I²C Adapter?
Space Efficiency: Perfect for compact projects where wiring space is limited
Time Savings: Dramatically reduces connection time and potential errors
Scalability: Add multiple LCDs to a single I²C bus (with unique addresses)
Professional Results: Creates cleaner, more maintainable projects
Pro Tip: Use an I²C scanner sketch to identify your module's address if the default doesn't work!
Package Includes: 1 x I2C Serial Interface Adapter Module