LCD Shield For Arduino

                                //#include <LCD4Bit_mod.h>
//create object to control an LCD.  //number of lines in
display=1LCD4Bit_mod lcd = LCD4Bit_mod(2); //Key messagechar
msgs[5][15] = {"Right Key OK ",                     "Up Key OK   
",                     "Down Key OK  ",                     "Left
Key OK  ",                     "Select Key OK" };int 
adc_key_val[5] ={30, 150, 360, 535, 760 };int NUM_KEYS = 5;int
adc_key_in;int key=-1;int oldkey=-1;void setup() {   pinMode(13,
OUTPUT);  //we'll use the debug LED to output a heartbeat 
lcd.init();  //optionally, now set up our application-specific
display settings, overriding whatever the lcd did in lcd.init() 
//lcd.commandWrite(0x0F);//cursor on, display on, blink on. 
(nasty!)   lcd.clear();  lcd.printIn("KEYPAD testing...
pressing");}void loop() {adc_key_in = analogRead(0);    // read the
value from the sensor  digitalWrite(13, HIGH);  key =
get_key(adc_key_in);    // convert into key press    if (key !=
oldkey)      // if keypress is detected      {    delay(50);       
 // wait for debounce time    adc_key_in = analogRead(0);    //
read the value from the sensor      key = get_key(adc_key_in);   
// convert into key press    if (key != oldkey)                    
               {                         oldkey = key;      if (key
>=0){      lcd.cursorTo(2, 0);  //line=2, x=0      
lcd.printIn(msgs[key]);      }    }  }  digitalWrite(13, LOW);}//
Convert ADC value to key numberint get_key(unsigned int input){    
  int k;  for (k = 0; k < NUM_KEYS; k++)       {              
if (input < adc_key_val[k])          {  return k;  } }    if (k
>= NUM_KEYS)        k = -1;     // No valid key pressed   
return k;}

Example use of LiquidCrystal library

                                //Sample using LiquidCrystal
library#include
<LiquidCrystal.h>/*******************************************************This
program will test the LCD panel and the buttonsMark Bramwell, July
2010********************************************************///
select the pins used on the LCD panelLiquidCrystal lcd(8, 9, 4, 5,
6, 7);// define some values used by the panel and buttonsint
lcd_key     = 0;int adc_key_in  = 0;#define btnRIGHT  0#define
btnUP     1#define btnDOWN   2#define btnLEFT   3#define btnSELECT
4#define btnNONE   5// read the buttonsint read_LCD_buttons(){
adc_key_in = analogRead(0);      // read the value from the sensor 
// my buttons when read are centered at these valies: 0, 144, 329,
504, 741 // we add approx 50 to those values and check to see if we
are close if (adc_key_in > 1000) return btnNONE; // We make this
the 1st option for speed reasons since it will be the most likely
result if (adc_key_in < 50)   return btnRIGHT;   if (adc_key_in
< 195)  return btnUP;  if (adc_key_in < 380)  return btnDOWN;
 if (adc_key_in < 555)  return btnLEFT;  if (adc_key_in <
790)  return btnSELECT;    return btnNONE;  // when all others
fail, return this...}void setup(){ lcd.begin(16, 2);             
// start the library lcd.setCursor(0,0); lcd.print("Push the
buttons"); // print a simple message} void loop(){
lcd.setCursor(9,1);            // move cursor to second line "1"
and 9 spaces over lcd.print(millis()/1000);      // display seconds
elapsed since power-up lcd.setCursor(0,1);            // move to
the begining of the second line lcd_key = read_LCD_buttons();  //
read the buttons switch (lcd_key)               // depending on
which button was pushed, we perform an action {   case btnRIGHT:   
 {     lcd.print("RIGHT ");     break;     }   case btnLEFT:     { 
   lcd.print("LEFT   ");     break;     }   case btnUP:     {    
lcd.print("UP    ");     break;     }   case btnDOWN:     {    
lcd.print("DOWN  ");     break;     }   case btnSELECT:     {    
lcd.print("SELECT");     break;     }     case btnNONE:     {    
lcd.print("NONE  ");     break;     } }}