// flex_lcd.c

// These pins are for the Microchip PicDem2-Plus board,
// which is what I used to test the driver.  Change these// pins to fit your own board.

#define LCD_DB4   PIN_A5
#define LCD_DB5   PIN_A4
#define LCD_DB6   PIN_A3
#define LCD_DB7   PIN_A2

#define LCD_E     PIN_C0
#define LCD_RS    PIN_C2
#define LCD_RW    PIN_C1

#define LCD_CGRAM_ADDR 0x40           // Set the CGRAM address
#define LCD_DDRAM_ADDR 0x80           // Set the DDRAM address 

// If you only want a 6-pin interface to your LCD, then
// connect the R/W pin on the LCD to ground, and comment
// out the following line.

#define USE_LCD_RW   1     

//========================================

#define lcd_type 2        // 0=5x7, 1=5x10, 2=2 lines
#define lcd_line_two 0x40 // LCD RAM address for the 2nd line



byte const LCD_CUSTOM_CHARS[64] = {
   0,     0,    0,    0,    0,    0,    0,   0,    // á
   2,     4,   14,   17,   31,   16,   14,   0,    // é
   2,     4,    0,   12,    4,    4,   14,   0,    // í
   2,     4,   14,   17,   17,   17,   14,   0,    // ó
   9,    18,    0,   14,   17,   17,   14,   0,    // õ
   2,     4,   17,   17,   17,   19,   13,   0,    // ú
   9,    18,    0,   17,   17,   19,   13,   0,    // û
   2,     4,   14,    1,   15,   17,   15,   0     // á
};


int8 const LCD_INIT_STRING[4] =
{
 0x20 | (lcd_type << 2), // Func set: 4-bit, 2 lines, 5x8 dots
 0xc,                    // Display on
 1,                      // Clear display
 6                       // Increment cursor
 };
                             

byte lcd_line = 1;


//-------------------------------------
void lcd_send_nibble(int8 nibble)
{
// Note:  !! converts an integer expression
// to a boolean (1 or 0).
 output_bit(LCD_DB4, !!(nibble & 1));
 output_bit(LCD_DB5, !!(nibble & 2)); 
 output_bit(LCD_DB6, !!(nibble & 4));   
 output_bit(LCD_DB7, !!(nibble & 8));   

 //delay_cycles(1);
 delay_us(10);
 output_high(LCD_E);
 delay_us(2);
 output_low(LCD_E);
}

//-----------------------------------
// This sub-routine is only called by lcd_read_byte().
// It's not a stand-alone routine.  For example, the
// R/W signal is set high by lcd_read_byte() before
// this routine is called.     

#ifdef USE_LCD_RW
int8 lcd_read_nibble(void)
{
int8 retval;
// Create bit variables so that we can easily set
// individual bits in the retval variable.
#bit retval_0 = retval.0
#bit retval_1 = retval.1
#bit retval_2 = retval.2
#bit retval_3 = retval.3

retval = 0;
   
output_high(LCD_E);
//delay_cycles(1);
delay_us(10);
retval_0 = input(LCD_DB4);
retval_1 = input(LCD_DB5);
retval_2 = input(LCD_DB6);
retval_3 = input(LCD_DB7);
 
output_low(LCD_E);
   
return(retval);   
}   
#endif

//---------------------------------------
// Read a byte from the LCD and return it.

#ifdef USE_LCD_RW
int8 lcd_read_byte(void)
{
int8 low;
int8 high;

output_high(LCD_RW);
//delay_cycles(1);
delay_us(10);
high = lcd_read_nibble();

low = lcd_read_nibble();

return( (high<<4) | low);
}
#endif

//----------------------------------------
// Send a byte to the LCD.
void lcd_send_byte(int8 address, int8 n)
{
output_low(LCD_RS);

#ifdef USE_LCD_RW
while(bit_test(lcd_read_byte(),7)) ;
#else
delay_us(60); 
#endif

if(address)
   output_high(LCD_RS);
else
   output_low(LCD_RS);
     
//delay_cycles(1);
delay_us(10);
 
#ifdef USE_LCD_RW
output_low(LCD_RW);
//delay_cycles(10);
delay_us(10);
#endif

output_low(LCD_E);

lcd_send_nibble(n >> 4);
lcd_send_nibble(n & 0xf);
}

//----------------------------
void lcd_init(void)
{
int8 i;

output_low(LCD_RS);

#ifdef USE_LCD_RW
output_low(LCD_RW);
#endif

output_low(LCD_E);

delay_ms(15);

for(i=0 ;i < 3; i++)
   {
    lcd_send_nibble(0x03);
    delay_ms(5);
   }

lcd_send_nibble(0x02);

for(i=0; i < sizeof(LCD_INIT_STRING); i++)
   {
    lcd_send_byte(0, LCD_INIT_STRING[i]);
   
    // If the R/W signal is not used, then
    // the busy bit can't be polled.  One of
    // the init commands takes longer than
    // the hard-coded delay of 60 us, so in
    // that case, lets just do a 5 ms delay
    // after all four of them.
    #ifndef USE_LCD_RW
    delay_ms(5);
    #endif
   }
lcd_line = 0;
}

//----------------------------

void lcd_gotoxy(int8 x, int8 y)
{
int8 address;

   switch(y) {
     case 1 : address=0x80;break;
     case 2 : address=0xC0;break;
     case 3 : address=0x90;break;
     case 4 : address=0xD0;break;
   }
   address += x-1;
   lcd_send_byte( 0, address );
   lcd_line = y;

/*
if(y != 1)
   address = lcd_line_two;
else
   address=0;
address += x-1;
lcd_send_byte(0, 0x80 | address);
*/
}

//-----------------------------
void lcd_putc(char c)
{

   switch (c) {
      case 'á': c = 0x07;  break;
      case 'é': c = 0x01;  break;
      case 'í': c = 0x02;  break;
      case 'ó': c = 0x03;  break;
      case 'õ': c = 0x04;  break;
      case 'ú': c = 0x05;  break;
      case 'û': c = 0x06;  break;
      case 'ö': c = 0xEF;  break;
      case 'ü': c = 0xF5;  break;
      case '°': c = 0xDF;  break;
   }


 switch(c)
   {
    case '\f':
      lcd_send_byte(0,1);
      delay_ms(2);
      break;
   
    case '\n':
       lcd_line++;	
       lcd_gotoxy(1,lcd_line);
       delay_ms(2);
       break;
   
    case '\b':
       lcd_send_byte(0,0x10);
       delay_ms(2);
       break;
   
    default:
       lcd_send_byte(1,c);
       break;
   }
}

//------------------------------
#ifdef USE_LCD_RW
char lcd_getc(int8 x, int8 y)
{
char value;

lcd_gotoxy(x,y);

// Wait until busy flag is low.
while(bit_test(lcd_read_byte(),7)); 

output_high(LCD_RS);
value = lcd_read_byte();
output_low(lcd_RS);

return(value);
}
#endif


void lcd_init_custom_chars()
{
BYTE i;

lcd_send_byte( 0, LCD_CGRAM_ADDR );
for( i=0; i<=63; i++ )
   {
   lcd_send_byte( 1, LCD_CUSTOM_CHARS[ i ] );
   delay_ms(2);   
   }
}