//Sample using LiquidCrystal library
#include <LiquidCrystal.h>

/*******************************************************

This program will test the LCD panel and the buttons of
the DFRobot LCD Keypad Shield for Arduino
Product code : RB-Dfr-07
http://www.robotshop.com/dfrobot-lcd-keypad-shield-arduino-1.html

Note cct error identified by Arduino forum discussion at:
http://arduino.cc/forum/index.php/topic,96747.0.html
which advises insertion of a Germanium 1n34a or a Schotky 1N5819
diode between pin 10 and the base of Q1 (K to pin 10).

sample code originally by Mark Bramwell, July 2010
modifications by Dion Weston, March 2012

********************************************************/

// select the pins used on the LCD panel
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);

// define some values used by the panel and buttons
int backLight = 10; // LCD Panel Backlight LED connected to digital pin 10
int lightLevel = 255; // Initialise light full on
int 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 buttons
int read_LCD_buttons()
{
adc_key_in = analogRead(0); // read the value from the sensor
// my [Mark Bramwell's] 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 LCD library
lcd.setCursor(0,0); // move cursor to beginning of line "0"
lcd.print("Backlight adjust"); // print a simple message

}

void loop()
{
analogWrite(backLight, lightLevel);
lcd.setCursor(13,1); // move to position 13 on the second line
lcd.print(lightLevel);

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("LED On ");
lightLevel = 255;
break;
}
case btnLEFT:
{
lcd.print("LED Off ");
lightLevel = 1;
break;
}
case btnUP:
{
lcd.print("LED Fade Up ");
if (lightLevel < 255) lightLevel += 1;
break;
}
case btnDOWN:
{
lcd.print("LED Fade Down ");
if (lightLevel > 1) lightLevel -= 1;
break;
}
case btnSELECT:
{
lcd.print("Select ");
break;
}
case btnNONE:
{
lcd.print(" ");
break;
}
}

}

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