Arduino drives I2C LCD Controller based on a LCD1602 module

LCD Software Library Information

ALL the displays will use the IMPORTANT Library written by Francisco Malpartida.You can download the Library:

the great Library

you must have the library installed correctly.

And Check the small backpack interface board on the back. These small boards on the back interface a 2wire IIC bus (unless Ground and +5V power) to the many pins on the LCD display itself. This allows running the display from only 2 signal pins on MEGA 2560.

These I2C interface displays have a built-in address. If you try to run the show and do not react or not show any code you are using the wrong address. You can check the address on the display when you run the Arduino address scanner in your IIC.

Scanner CODE:

// I2C Scanner
// Written by Nick Gammon
// Date: 20th April 2011

#include 

void setup() {
  Serial.begin (115200);

  // Leonardo: wait for serial port to connect
  while (!Serial) 
    {
    }

  Serial.println ();
  Serial.println ("I2C scanner. Scanning ...");
  byte count = 0;

  Wire.begin();
  for (byte i = 8; i < 120; i++)
  {
    Wire.beginTransmission (i);
    if (Wire.endTransmission () == 0)
      {
      Serial.print ("Found address: ");
      Serial.print (i, DEC);
      Serial.print (" (0x");
      Serial.print (i, HEX);
      Serial.println (")");
      count++;
      delay (1); 
      } // end of good response
  } // end of for loop
  Serial.println ("Done.");
  Serial.print ("Found ");
  Serial.print (count, DEC);
  Serial.println (" device(s).");
}  // end of setup

void loop() {}

To directly use this type of liquid crystal Arduino, it takes 6 pins: RS, EN, D7, D6, D5, D4, and LCD. If you are more than a simple project, you may be out of the use of the ordinary LCD shield pin. With this I2C interface LCD module, you only need 2 lines (I2C) to display information. If you already have I2C devices in your project, this LCD module is actually using no more pins.

Top to bottom: GND - GND VCC - +5V SDA - communication Pin 20 SCL - communication pin 21

Example Software code for 4 line 20 character Displays:

#include  
#include 

LiquidCrystal_I2C lcd(0x3F,16,2);  

void setup()
{
  lcd.init();                    

  // Print a message to the LCD.
  lcd.backlight();
  lcd.setCursor(0,0);
  lcd.print("Hello, body!");
  delay(1000);
  lcd.setCursor(0,1);
  lcd.print("HI!EasyEDA.com");
  delay(8000); 
}

void loop()
{

}