Haven Farm

Arduino LCD

The Arduino LiquidDisplay library lets you control Hitachi HD44780 compatible LCDs. These are inexpensive displays that are quite common. (I got mine from eBay, $3-5 each). This project uses a 2x16 LCD.

Parts:

1 Arduino micro-controller
1 HD44780 compatible LCD (2x16)
1 solderless bread-board (for prototyping)
Jumper wires

The LCD can be driven with either 4 or 8 data pins. If using 4, the first 4 pins can be ignored (DB0-DB3). The LiquidDisplay() constructor takes a number of parameters:


LiquidCrystal(rs, rw, enable, d4, d5, d6, d7)

rs: the Arduino pin that connects to the RS pin on the LCD
rw: the Arduino pin that connects to the RW pin on the LCD
enable: the Arduino pin that connects to the E pin on the LCD
d4-d7: the 4 Arduino pins that connect to DB4-DB7 pins on the LCD

I have it connected as follows:

LCD	Arduino
1 (GND)	GND
2 (VDD)	5v
3 (VO/Contrast)	GND
4 (RS)	2
5 (RW)	3
6 (E/enable)	4
11 (DB4)	9
12 (DB5)	10
13 (DB6)	11
14 (DB7)	12
15 (BL1/Backlight1)	5v
16 (BL2/Backlight2)	GND

Code


#include 

LiquidCrystal lcd(2,3,4,9,10,11,12);

void setup() {
  lcd.begin(16,2);
  lcd.setCursor(0,0);
  lcd.print("Arduino");
  lcd.setCursor(0,1);
  lcd.print("Rocks!");
}

void loop() {
  delay(5000);
}

For more info, see: LiquidCrystal Library