#include <LiquidCrystal.h>

int keyIn = 0;                        //Variable for keypad input
int keyVals [16] = {423, 454, 503, 562, 429, 459, 507, 565, 451, 480, 525, 579, 462, 487, 531, 585};    //Array to store keypad numerical values
char keys [16] = {'1','2','3','4','5','6','7','8','9','10','11','12','13','14','15','16'};   //Key characters corressponding to each numerical value
int range = 3;                        //Tolerance above or below the numerical value

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);  //Assign LCD screen pins, as per LCD shield requirements

void setup() 
{ 
  lcd.begin(16,2);              // columns, rows.  use 16,2 for a 16x2 LCD, etc.
  lcd.clear();
  lcd.setCursor(0,0);           //Display some text on LCD then clear it
  lcd.print("Keypad");          
  lcd.setCursor(0,1);
  lcd.print("One Input");
  delay(2000);
  lcd.clear();
  Serial.begin(9600);
}

void loop() 
{
  keyIn =  analogRead(A1);      //Read in keypad input
  Serial.println(keyIn);
  String temp = "";             //Create a variable to store the key character
  for (int i=0; i<=15; i++)     //Run through the array of button values
  {
    if (keyIn >= keyVals[i]-range && keyIn <= keyVals[i]+range)   //If the measured value is in the range of one key
    {
      temp = keys[i];     //Set temp equal to the character for that key
    }
  }
  lcd.print("Button: ");
  lcd.print(temp);             //Display button character on the LCD
  delay(1000);                  //Wait one second
  lcd.clear();                  //Clear the display
}