IIC/I2C Serial Interface Adapter Module

An IIC/I2C Serial Interface Adapter Module is a small board that allows you to control devices—especially LCD displays—using the I²C (Inter-Integrated Circuit) communication protocol. It significantly reduces the number of GPIO pins needed to control an LCD.

What It’s Commonly Used For

• Most often used with 1602 or 2004 character LCDs
• Converts the standard 16-pin parallel interface of an LCD into a 2-wire I²C interface
• Allows easy connection to microcontrollers (like Arduino, Raspberry Pi, etc.)

Key Features

Protocol I²C (IIC)

Power Supply 5V (some support 3.3V too)

I²C Address Usually 0x27 or 0x3F (configurable)

Adjustments Potentiometer for contrast, solder pads for address change

Connections GND, VCC, SDA, SCL

PCF8574 Chip Most modules use this I/O expander chip

Pinout (I²C Interface)

GND Ground

VCC Power (typically 5V)

SDA I²C Data

SCL I²C Clock

Arduino Code Example

#include <Wire.h>
#include <LiquidCrystal_I2C.h>

// Set LCD address to 0x27 (or 0x3F), and dimensions: 16 chars, 2 lines
LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup() {
  lcd.init();           // Initialize LCD
  lcd.backlight();      // Turn on the backlight
  lcd.print("Hello, world!");
}

void loop() {
  // Nothing to do here
}

Tips

• If the screen stays blank:
• Adjust the contrast potentiometer
• Double-check the I²C address using an I2C Scanner sketch
• To use multiple devices, ensure each has a unique I²C address
• Libraries: LiquidCrystal_I2C, Wire

Origin:- China

Brand:- Generic