// include the library code:
 #include <LiquidCrystal.h>

 const int numRows = 2;
 const int numCols = 16;
 
 const int lcdBackLightPin = 12;
 const int upButtonPin = 6;
 const int downButtonPin = 5;
 const int setButtonPin = 4;
 const int resetButtonPin = 3;
 
 char* mainMenu[]={"start", "delay", "test"};
 int mainMenuIndex = 0;
 int mainMenuNextItem = 1;
 int mainMenuItemNum = 3;
 boolean menuUpdate = false;

 // initialize the library with the numbers of the interface pins
 LiquidCrystal lcd(13, 11, 10, 9, 8, 7);

 void setup() {
   // set up the LCD's number of rows and columns: 
   lcd.begin(numRows, numCols);
   lcd.clear();
   lcd.setCursor(0, 0);
   lcd.print(">");
   lcd.setCursor(2, 0);
   lcd.print(mainMenu[mainMenuIndex]);
   lcd.setCursor(2, 1);
   lcd.print(mainMenu[mainMenuNextItem]);
   digitalWrite(lcdBackLightPin, HIGH);
   
   pinMode(lcdBackLightPin, OUTPUT);
   pinMode(upButtonPin, INPUT);
   pinMode(downButtonPin, INPUT);
   pinMode(setButtonPin, INPUT);
   pinMode(resetButtonPin, INPUT);
   
   
 }

 void loop() {
   if(digitalRead(upButtonPin))
   {
     mainMenuIndex++;
     if(mainMenuIndex >= mainMenuItemNum)
     {
       mainMenuIndex = 0;
     }  
     mainMenuNextItem++;
     if(mainMenuNextItem >= mainMenuItemNum)
     {
       mainMenuNextItem = 0;
     }
     menuUpdate = true;
   }
   else if(digitalRead(downButtonPin))
   {
     mainMenuIndex--;
     if(mainMenuIndex < 0)
     {
       mainMenuIndex = mainMenuItemNum - 1;
     }  
     mainMenuNextItem--;
     if(mainMenuNextItem < 0)
     {
       mainMenuNextItem = mainMenuItemNum - 1;
     }
     menuUpdate = true;
   }

   if(menuUpdate)
   {   
     lcd.clear();
     lcd.setCursor(0, 0);
     lcd.print(">");
     lcd.setCursor(2, 0);
     lcd.print(mainMenu[mainMenuIndex]);
     lcd.print(" <");
     lcd.setCursor(2, 1);
     lcd.print(mainMenu[mainMenuNextItem]);
     menuUpdate = false;
     delay(300);
   }
   
 }