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)