I2C LCD MODULE

Description

These convenient devices are used to give HD44780-compatible interface LCD modules a serial interface via the I2C bus. This allows you to control the LCD with only two data wires from your microcontroller (and power of course).

We may send one of two versions of this device – the difference is the controller IC. If you have the PCF8574T. the default I2C bus address is 0x27. If you have the PCF8574AT the default I2C bus address is 0x3F.

A jumper on the back controls power to the backlight, and a contrast potentiometer is also fitted.

I2C interface for LCD

This LCD2004 is a great I2C interface for 2×16 and 4×20 LCD displays. With the limited pin resources, your project may be out of resources using normal LCD shield. With this I2C interface LCD module, you only need 2 lines (I2C) to display the information. If you already has I2C devices in your project, this LCD module actually cost no more resources at all. Fantastic for Arduino based projects.

Specification

• Compatible with 16×2 and 20×4 LCD’s
• Default I2C Address = 0X27
• Address selectable – Range 0x20 to 0x27

Board Layout

I2C Address Setup

The LCD2004 board utilized the PCF8574 I/O expander. This nifty little chip provides eight bits of parallel I/O addressable by a I2C bus address – 0x00 to 0x27. SainSmart tied all address leads to Vcc, so the LCD2004 board’s I2C address is permanently fixed at hex 27. This is rather limiting since no additional LCD2004s can be added to the bus. Anyway, you simply address the board and write an eight bit value which is then presented on the output pins of the PCF8574, which, in this case, are connected to the HD44780 based LCD screen.

Controlling your I2C Display with Arduino

Arduino Code

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

// Set the LCD address to 0x27 for a 16 chars and 2 line display

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()

{

// initialize the LCD

lcd.begin();

// Turn on the blacklight and print a message.

lcd.backlight();

lcd.print(“Hello, world!”);

}

void loop()

{

// Do nothing here…

}