/*
    Demo of LCD and button shield.

    For details, see:
    http://hblok.net

    http://hblok.net/blog/posts/tag/LCD

    This program is free software: you can redistribute it and/or modify
    it under the terms of the GNU General Public License as published by
    the Free Software Foundation, either version 3 of the License, or
    (at your option) any later version.

    This program is distributed in the hope that it will be useful,
    but WITHOUT ANY WARRANTY; without even the implied warranty of
    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
    GNU General Public License for more details.

    You should have received a copy of the GNU General Public License
    along with this program.  If not, see <http://www.gnu.org/licenses/>.
*/

#include <LiquidCrystal.h>

LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

void setup() {
  pinMode(10, OUTPUT);  // for backlight adjustment
  
  lcd.begin(16, 2);

  lcd.print("Hello World!");
}

int button_value;

int light = 100;

void loop() {
  lcd.setCursor(0, 1);
  lcd.print(millis()/1000);
  
  button_value = analogRead(A0);
  
  if (button_value == 132)
    light = min(light + 1, 255);
    
  if (button_value == 306)
    light = max(light - 1, 0);
  
  analogWrite(10, light);  

  String tmp = " ";
  tmp += light;
  tmp += " ";
  tmp += button_value;
  tmp += "   ";  // erase previous digits

  lcd.setCursor(4, 1);  
  lcd.print(tmp);
}