LCD shield -Analog input A0 changes value continuously

Other Hardware Displays
3

A0 is used to read the analog value from the keypad to determine which key is pressed.

Did you use their libraries?

Why are your test values so high?

Follows is some code from their site and notice the values for the 5 keys.

// include this library's description file

#include <LiquidCrystal.h>
#include "LCDKeypad.h"

LCDKeypad::LCDKeypad() : LiquidCrystal(8, 9, 4, 5, 6, 7)
{
}

int LCDKeypad::button()
{
  static int NUM_KEYS=5;
  static int adc_key_val[5] ={  
    30, 150, 360, 535, 760     };
  int k, input;
  input=analogRead(0);
  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;
}