MENWIZ: yet another character lcd menu wizard library

Ciao a tutti,
I am a very beginner (it's my first week on Arduino), no experience in programming, I already read the guide and the book "Getting Started With Arduino 2ndEd" ..... but .... it's still a long way ....
Anyway, what I am trying to do is to make an actuator with a stepper (and a relative mechanical transmission) to move the height of a the saw in a table saw. I need to set the height to a certain amount of mm, or to move of a certain amount on mm.
Now my starting problem is to use Menwiz with the classic LCD Keypad Shield (16x2) that have 5 analog buttons (it's perfectly ok to use only 4).
(From this tutorial which is perfecly working I took some setup:

http://tutorial.cytron.com.my/2011/08/12/project-1-“hello-world”-on-lcd/)

#include <LiquidCrystal.h>
LiquidCrystal lcd(8, 9, 4, 5, 6, 7); //this is the working pins

[sup]LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Addr, En, Rw, Rs, d4, d5, d6, d7, 
backlightpin, polarity 4 x 20 LCD //this is what I replaced
[/sup]

and from Backbone post « Reply #188 on: September 27, 2012, 07:17:31 PM » I took his example changing the button parameters:

// +++++++ Libaries included
#include <Wire.h>
#include <LiquidCrystal.h>
//INSERT ALL THE LIBARIES AFTER INCLUDING WIRE LIB (MENWIZ request)
#include <LiquidCrystal_I2C.h>
#include <buttons.h>
#include <MENWIZ.h>
#include <EEPROM.h>

// Create global object for menu and lcd
menwiz menu;
LiquidCrystal lcd(8, 9, 4, 5, 6, 7);
/*LiquidCrystal_I2C lcd(0x27, 2, 1, 0, 4, 5, 6, 7, 3, POSITIVE); // Addr, En, Rw, Rs, d4, d5, d6, d7, backlightpin, polarity 4 x 20 LCD
*/
boolean wr=0; // Instantiate global variables to bind to menu

const int buttonPin = A0;             // 4 button switch circuit input connected to analog pin 0
const int led13Pin = 13;              // the number of the LED output pin

boolean buttonBlock = 0;
boolean buttonAct = 0; // flag 1
boolean stopMenu = 0; // flag 2
byte buttonPressed = 0;  // which button was pressed
byte lastButtonPressed = 0; // prev button pressed
int buttonValue = 0;  // read value from analog port for the 4 navigation pushbuttons
long menuOffTime = 0;  //used for timer

extern byte MW_navbtn;  //needed to run the software key navigation in Menwiz



void setup()
{
  Serial.begin(9600);                       // Output to serial writing

  digitalWrite((54), HIGH);  // enable the 20k internal pullup for MEGA board for analog port A0
  // digitalWrite((A0), HIGH);  // enable the 20k internal pullup for UNO based board for analog port A0

  //++++++++++++++++++++Menu and LCD  
  char b[84];
  _menu *r,*s1,*s2;

  // initialize the menu object ( 4 x rows x 20 colums LCD)
  menu.begin(&lcd,16,2); //initialize the menwiz menu object passing the lcd object and the colums and rows params 
  menu.addUsrNav(navMenu,4);
  MW_navbtn=4;  // force 4 or 6 buttons mode for menu navigation -> MW_navbtn=4; or MW_navbtn=6;

  //create the menu tree
  r=menu.addMenu(MW_ROOT,NULL,F("MAIN MENU"));                      //create a root menu at first (required)

  //---------------  
  s1=menu.addMenu(MW_SUBMENU,r,F("SET1"));                        //add a submenu node 1 to the root menu
  s2=menu.addMenu(MW_VAR,s1,F("MD"));                         //add a terminal node in the menu tree (that is "variable");
  s2=menu.addMenu(MW_VAR,s1,F("BR"));                         //add a terminal node in the menu tree (that is "variable");
  s2=menu.addMenu(MW_VAR,s1,F("RH"));                         //add a terminal node in the menu tree (that is "variable");

  //---------------
  s1=menu.addMenu(MW_SUBMENU,r,F("SET2"));                    //add a submenu node 2 to the root menu
  s2=menu.addMenu(MW_VAR,s1,F("CP"));                         //add a terminal node in the menu tree (that is "variable");
  s2=menu.addMenu(MW_VAR,s1,F("DB"));                         //add a terminal node in the menu tree (that is "variable");
  s2=menu.addMenu(MW_VAR,s1,F("SQ"));                         //add a terminal node in the menu tree (that is "variable");

  //---------------
  s1=menu.addMenu(MW_SUBMENU,r,F("SET3"));                    //add a submenu node 3 to the root menu
  s2=menu.addMenu(MW_VAR,s1,F("RS"));                         //add a terminal node in the menu tree (that is "variable");
  s2=menu.addMenu(MW_VAR,s1,F("RCALIB"));                     //add a terminal node in the menu tree (that is "variable");
  s2=menu.addMenu(MW_VAR,s1,F("SCALIB"));                     //add a terminal node in the menu tree (that is "variable");

/*
  //++++++ Splash screen +++++++
  
  sprintf(menu.sbuf,"TEST minimum menu\nwith 4 or 6\nanalog push buttons\n",1);
  menu.addSplash((char *) menu.sbuf, 1000);

  //++++++ Userscreen ++++++++++
  // create an user define screen callback to activate after X secs since last button push
  menu.addUsrScreen(msc,3000);
*/
  pinMode(led13Pin, OUTPUT);                // initialize the led as a output control pin
}

void loop()    
{
// NAVIGATION MANAGEMENT & DRAWING ON LCD. NOT BLOCKING has to be the first in the void loop
  menu.draw();
/*
  put your regular code here
   */
  readButtons();
}

//  ++++++ functions +++++++

void readButtons()

// ++++ Control 4 buttons ++++
{
  lastButtonPressed = buttonPressed;

  /*
  Analog values representing the pushbutton value are depending on the resitor value used.
   Test the values first with the serial.monitor
   */
  buttonValue = analogRead(buttonPin); //analog value to simulate the pushed buttons

  if(buttonValue >= 700)
  {
    buttonPressed = 0;
    noButtonPressed(); // is calling an extra fucntion
  }
  else  if(buttonValue >= 470 & buttonValue <= 600)
  {
    buttonPressed = 4;
    buttonAct = 1; // set the menu flag1
  }
  else if(buttonValue >= 300 & buttonValue <=420)
  {    
    buttonPressed = 3;
    buttonAct = 1; // set the menu flag1
  }
  else if(buttonValue >= 100 & buttonValue <=200)
  {    
    buttonPressed = 1;
    buttonAct = 1; // set the menu flag1
  }
  else if(buttonValue >= 10 & buttonValue <=50)
  {    
    buttonPressed = 2;
    buttonAct = 1; // set the menu flag1
  }
}

int noButtonPressed()
{
  return MW_BTNULL;
}

int navMenu() // called from menu.draw
{
  /*
   As soon as a button is pushed the first time flag 1 is set to HIGH and if the buttonnumber is not 0 then a timer is started.
   The menu action then should only be performed once.
   After 2000 msecs the flag will be set to LOW and a new buttonpush can be processed.
   Menu action is blocked for 2000 msec even if the same button is being kept pressed for 2000 msecs by flag2.
   */

  long menublockTime = millis();

  if (buttonAct == 1 && buttonPressed != 0 && stopMenu == 0)  // we have a state were we process a menu navigation step once and block it for 2 secs
  {
    digitalWrite(led13Pin,HIGH);  // set timer led ON
    menuOffTime = menublockTime  + 2000; //start the timer. You can change this blocking time to your convenience but do not make it lower aa 200 msecs
    stopMenu = 1;

    switch (buttonPressed)
    {
    case 1: // Up
      return MW_BTU;
      break;
    case 2: // Confirm
      return MW_BTC;
      break;
    case 3: // Down
      return MW_BTD;
      break;    
    case 4: // Escape
      return MW_BTE;
      break;
    }
  }

  if (menuOffTime != 0  &&  menublockTime  > menuOffTime)  //  Reset of the timer so a new menu action can be processed
  {
    buttonAct = 0; // resets the flag 1
    buttonPressed = 0;
    menuOffTime = 0;  // resets timer to zero
    stopMenu = 0;
    digitalWrite(led13Pin,LOW);  // set timer led OFF
  }
}

// user defined default screen.
void msc()
{
  sprintf(menu.sbuf,"User screen\nUptime (s): %ld\nFree mem  : %d\n\n",millis()/1000,(int)menu.freeRam());
  menu.drawUsrScreen(menu.sbuf);
}

that was the code for the buttons on the "helloWorld" example (it's a completely different approach from the Backbone one:

int analogPin = A0;
int adc_key_old;
int adc_key_in;
int NUM_KEYS = 5;
int key=-1;
int adc_key_val[5] ={30, 150, 360, 535, 760 };  

//omitted some functions , then ...

int get_key(unsigned int input)
{
	int k;
    
	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;
}

I am not asking to check all the code, but can somebody check if I did some noticeable error in manipulating the code ?
Thanks from a beginner.
Sergio