I2C Module for 16×2 LCD Display

The I2C Module for 16×2 LCD Display is a PCF8574-based I2C backpack that converts parallel HD44780 LCD interfaces to I2C. It dramatically reduces pin count from 6-7 pins to just 2 (SDA/SCL) for easy microcontroller integration.

Key Features

• PCF8574 I2C expander chip
• Reduces pin count from 6-7 to 2 pins
• I2C interface at 100kHz or 400kHz
• Adjustable I2C address via solder jumpers
• Backlight control via I2C commands
• Onboard contrast potentiometer

Technical Specifications

Applications

• Pin-constrained projects
• I2C bus-based systems
• Adding LCD to Raspberry Pi
• Multi-sensor projects needing many GPIO
• Neater wiring setups
• LCD retrofitting existing projects

Important Notes

• Must solder to LCD – requires basic soldering skills
• Default address varies by manufacturer – use I2C scanner
• Install LiquidCrystal_I2C library for Arduino
• Some modules have backlight always on – others controllable
• If display is blank, check contrast pot and I2C address