1. Forewords
It is the original sample, changed only the pins involved...
2. Setting the boardWe must have the following wire connections (don't power your board yet):
Wire connections
| | | ATmega pins
| LCD pins
| Assigned name
| Digital 22
| RS
| none
| Digital 23
| E
| none | | Digital 24 | A4 | none | | Digital 25 | A5 | none | | Digital 26 | A6 | none | | Digital 27 | A7 | none |
Now, connect your USB cable, start Arduino 0019 and write the following sketch:
3. The sketch
/*
This sketch prints "Hello World!" to the LCD
and shows the time.
The circuit:
* LCD RS pin to digital pin 22
* LCD Enable pin to digital pin 23
* LCD D4 pin to digital pin 24
* LCD D5 pin to digital pin 25
* LCD D6 pin to digital pin 26
* LCD D7 pin to digital pin 27
Library originally added 18 Apr 2008
by David A. Mellis
library modified 5 Jul 2009
by Limor Fried (http://www.ladyada.net)
example added 9 Jul 2009
by Tom Igoe
modified 8 Feb 2010
by Tom Igoe
*/
// include the library code:
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(22, 23, 24, 25, 26, 27);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.print("hello, world!");
}
void loop() {
// set the cursor to column 0, line 1
// (note: line 1 is the second row, since counting begins with 0):
lcd.setCursor(0, 1);
// print the number of seconds since reset:
lcd.print(millis()/1000);
}
Upload the sketch.
4. Results
As you can see, I disabled the backlight of the LCD... it is wise to consume less when you connect to USB. | 
