PCF8574T I2C IO Expansion Interface Board for 16×2, 20×2, 20×4 Character LCD Modules (Black)

Description

I2C Interface Board is basically an IO expander board that helps minimize microcontroller / Arduino IO usage pin count. With this module, attached to the back of an character LCD Module, you can use only two pins (SDA and SCL) to the LCD modules.

Specifications

• The contrast is adjusted by larger potentiometer for easy access
• Serial Interface: I2C
• Compatible with 1602, 20×2, 16×4, 20×4 character LCD Modules
• Operating voltage range: 2.6V – 6.0V
• Chip: PCF8574T
• Configureable I2C Addresses (0 – 7) through A0, A1, A2 pcb jumpers.
• Up-to eight IO Expander Modules can be connected on single I2C Bus
• Compatible LCD Controllers: HD447800, KS0066, KS0077, or compatibles
• LCD Databus width utilized: 4 Data Bits.

Datasheet

• PCF8574T I2C IO Expander IC

Applications

• Arduino LCD Interfacing
• Raspberry-Pi LCD Interfacing
• Beagle Board LCD interfacing

Documents and Downloads

• Arduino Library
• Arduino Example

Notes

Use following Arduino C statement to initialize LCD:

LiquidCrystal_I2C  lcd(0x27,2,1,0,4,5,6,7,3,POSITIVE); // some devices have 0x27 default address

or

LiquidCrystal_I2C  lcd(0x3f,2,1,0,4,5,6,7,3,POSITIVE);  //some devices have 0x3f default address

You can also use I2C Scanner code to find out real i2c address of i2c-io expansion module. Also make sure you pull-up I2C SDA line.

[!] Make sure that LCD Back-Light has a series resistor already installed, or you will burn the LCD Back Light.

Package Includes

• 1x I2C IO Expansion Board (Without LCD)