The LCD Keypad shield is developed for Arduino compatible boards, to provide a user-friendly interface that allows users to go through the menu, make selections etc. It consists of a 1602 white character blue backlight LCD. The keypad consists of 5 keys — select, up, right, down and left. To save the digital IO pins, the keypad interface uses only one ADC channel. The key value is read through a 5 stage voltage divider.
Reference
http://www.dfrobot.com/wiki/index.php?title=Arduino_LCD_KeyPad_Shield_(SKU:_DFR0009)
Code
// include the library code:
#include <LiquidCrystal.h>
// initialize the library with the numbers of the interface pins
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
void setup() {
// set up the LCD's number of columns and rows:
lcd.begin(16, 2);
// Print a message to the LCD.
lcd.setCursor(0,0);
lcd.print("LCD Key Shield");
lcd.setCursor(0,1);
lcd.print("Press Key:");
}
void loop() {
int x;
x = analogRead (0);
lcd.setCursor(10,1);
if (x < 60) {
lcd.print ("Right ");
}
else if (x < 200) {
lcd.print ("Up ");
}
else if (x < 400){
lcd.print ("Down ");
}
else if (x < 600){
lcd.print ("Left ");
}
else if (x < 800){
lcd.print ("Select");
}
}