#define MENU_LENGTH 2

sbit LCD_RS at LATD2_bit;
sbit LCD_EN at LATD3_bit;
sbit LCD_D4 at LATD4_bit;
sbit LCD_D5 at LATD5_bit;
sbit LCD_D6 at LATD6_bit;
sbit LCD_D7 at LATD7_bit;
sbit LCD_RS_Direction at TRISD2_bit;
sbit LCD_EN_Direction at TRISD3_bit;
sbit LCD_D4_Direction at TRISD4_bit;
sbit LCD_D5_Direction at TRISD5_bit;
sbit LCD_D6_Direction at TRISD6_bit;
sbit LCD_D7_Direction at TRISD7_bit;

char* menu[MENU_LENGTH] = {"KALIBRACIJA", "TESTIRANJE"} ;
int current_menu_item;
int states[16];
float kalibraciona_konstanta = 1;

int button_released(int, unsigned int *, unsigned int);
void display_menu_item(int);
void display_next_menu_item();
void display_prev_menu_item();
void run_function();
void Lcd_Read(char *);
int Lcd_Read_Int(char *);
void kalibracija();
void testiranje();
int StrToInt(char*);
int ADC_read_custom();
void strip_blanks(char *, char *);

void main()
{
  Lcd_Init();

  TRISE |= 0b0000000001110000;
  TRISF |= 0b0000000011110000;
  TRISG |= 0b0111000000000111;

  TRISBbits.TRISB1 = 1;
  AD1PCFGbits.PCFG1 = 0; //pin RB1 definisan kao analogni ulaz
  AD1CON3bits.ADRC = 0; //sistemski takt
  AD1CON3bits.ADCS = 0b00000011; //ADCS=3 - fosc/8
  AD1CON1bits.SSRC = 0b000; //strat konverzije - manuelno
  AD1CON1bits.ASAM = 0; //start odabiranja - manuelno
  AD1CHSbits.CH0SA3  = 0;
  AD1CHSbits.CH0SA2  = 0;
  AD1CHSbits.CH0SA1  = 0;
  AD1CHSbits.CH0SA0  = 1; //prvi kanal - pin RB1
  AD1CON1bits.ADON = 1;  //ADC on

  display_menu_item(0);

  do
  {
     if(button_released(12, &PORTG, 12)) display_prev_menu_item();
     if(button_released(13, &PORTG, 13)) display_next_menu_item();
     if(button_released(14, &PORTG, 14)) run_function();
  }while(1);
}

void run_function()
{
  switch(current_menu_item)
  {
    case 0:
         kalibracija();
         break;
    case 1:
         testiranje();
         break;
  }
}

/*------------- KALIBRACIJA -------------*/
void kalibracija()
{
  char s[17];
  int voltage;
  int d;      //digitalni ekvivalent referentnog napona

  voltage = Lcd_Read_Int("Unesi Vref [mV]:");

  Lcd_Cmd(_Lcd_Clear);
  Lcd_Cmd(_Lcd_First_Row);
  Lcd_Out(1,1,"kalibracija");
  Lcd_Out(2,1,"u toku...");
  Lcd_Cmd(_Lcd_Cursor_Off);
  delay_ms(1000);

  d = ADC_read_custom();
  kalibraciona_konstanta = (voltage/1000.0) / d;

  Lcd_Cmd(_Lcd_Clear);
  Lcd_Cmd(_Lcd_First_Row);

  FloatToStr(kalibraciona_konstanta, s);
  Lcd_Out(1, 1, "konstanta:");
  Lcd_Out(2, 1, s);
  Lcd_Cmd(_Lcd_Cursor_Off);

  delay_ms(1000);
}

int ADC_read_custom()
{

  AD1CON1bits.SAMP = 1;                // start odabiranja
  Delay_ms(100);                  // odabira ...
  AD1CON1bits.SAMP = 0;         // Clear SAMP bit,start konverzije
  while(AD1CON1bits.DONE == 0); // ceka kraj konverzije
  return ADC1BUF0;                // vrati rezultat konverzije
}

/*------------- testiranje --------------------*/

void testiranje()
{
  float V; //mjereni napon [V]
  char s[7];
  char buf[16] = "";
  char line1[16];
  Lcd_Cmd(_Lcd_Clear);
  Lcd_Cmd(_Lcd_Cursor_Off);
  Lcd_Out(1,1,"Napon [V]:");
  while(1)
  {
    V = kalibraciona_konstanta * ADC_read_custom();
    FloatToStr(V,buf);
    //sprintf(s,"%.4f",V);
    Lcd_Out(2,1,"               ");
    Lcd_Out(2, 1, buf);
  }
}

/*------------- korisne funkcije --------------*/

void strip_blanks(char *in, char *out)
{
  int i,j;
  int len=0;
  len = strlen(in);

  for(j=0,i=0; i<len; i++) if(in[i] != ' ') out[j++] = in[i];

  out[j] = '\0';
}

int StrToInt(char *s)
{
  int num_digits;
  char digit;
  char c;
  int result = 0;
  int exp;
  int i=0;
  int st;
  int j=0;

  num_digits = strlen(s);
  while(s[i] != '\0')
  {
    c = s[i];
    digit = c - '0';
    st=1;
    exp = num_digits-i-1;
        for (j=0 ; j < exp; j++)
        {
                st*=10;
        }
    result+=digit*st;
    i++;
  }
  return result;
 }

void Lcd_Read(char * buffer)
{
  int i = 0;
  do{
    if(button_released( 0, &PORTE,  4)) { Lcd_Chr_Cp('1'); buffer[i++] = '1'; }
    if(button_released( 1, &PORTF,  4)) { Lcd_Chr_Cp('2'); buffer[i++] = '2'; }
    if(button_released( 2, &PORTG,  0)) { Lcd_Chr_Cp('3'); buffer[i++] = '3'; }
    if(button_released( 3, &PORTE,  5)) { Lcd_Chr_Cp('4'); buffer[i++] = '4'; }
    if(button_released( 4, &PORTF,  5)) { Lcd_Chr_Cp('5'); buffer[i++] = '5'; }
    if(button_released( 5, &PORTG,  1)) { Lcd_Chr_Cp('6'); buffer[i++] = '6'; }
    if(button_released( 6, &PORTE,  6)) { Lcd_Chr_Cp('7'); buffer[i++] = '7'; }
    if(button_released( 7, &PORTF,  6)) { Lcd_Chr_Cp('8'); buffer[i++] = '8'; }
    if(button_released( 8, &PORTG,  2)) { Lcd_Chr_Cp('9'); buffer[i++] = '9'; }
    if(button_released( 9, &PORTF,  7)) { Lcd_Chr_Cp('0'); buffer[i++] = '0'; }
  }while(i < 16 && !button_released(14, &PORTG, 14));

  buffer[i] = '\0';
}

int Lcd_Read_Int(char *label)
{
  char buffer[17];
  Lcd_Cmd(_Lcd_Clear);
  Lcd_Out(1, 1, label);
  Lcd_Cmd(_LCD_SECOND_ROW);
  Lcd_Read(buffer);
  Lcd_Cmd(_LCD_CLEAR);
  return StrToInt(buffer);
}

int button_released(int i, unsigned int *port, unsigned int pin)
{
    if (Button(port, pin, 1, 1))
    {
      states[i] = 1;
    }
    if (states[i] && Button(port, pin, 1, 0))
    {
      states[i] = 0;
      return 1;
    }
    return 0;
}

/*----- MENU HANDLING ------*/

void display_menu_item(int index)
{
   Lcd_Cmd(_Lcd_Clear);
   Lcd_Out_Cp(menu[index]);
   Lcd_Cmd(_Lcd_Cursor_Off);
   current_menu_item = index;
}

void display_next_menu_item()
{
  if(current_menu_item < MENU_LENGTH-1) display_menu_item(current_menu_item+1);
  else display_menu_item(0);
}

void display_prev_menu_item()
{
  if(current_menu_item > 0) display_menu_item(current_menu_item-1);
  else display_menu_item(MENU_LENGTH-1);
}