AVR Freaks

Port	Header	Function
A0 	1 	LCD D4
A1 	2 	LCD D5
A2 	3 	LCD D6
A3 	4 	LCD D7
A4 	5 	LCD R/~W
A5 	6 	LCD E
A6 	7 	LCD RS
A7 	8 	unused
GND	9 	GND
Vtg	10	Vcc 

http://www.gnu.org/savannah-checkouts/non-gnu/avr-libc/user-manual/group__stdiodemo.html

/*
Port	Header	Function
A0 	1 	LCD D4
A1 	2 	LCD D5
A2 	3 	LCD D6
A3 	4 	LCD D7
A4 	5 	LCD R/~W
A5 	6 	LCD E
A6 	7 	LCD RS
A7 	8 	unused
GND	9 	GND
VCC	10	Vcc 
*/




#define F_CPU 1000000
#include 
#include 

// Define LCD Register Select as PORTA, 0x10;
#define LCD_RS 7
// Define LCD Read/Write as PORTA, 0x20;
#define LCD_RW 5
// Define LCD Enable as PORTA, 0x40;
#define LCD_E 6

// DISPLAY ON, 2 LINE MODE
#define   PWR_CMD1   0x20
#define   PWR_CMD2   0x20
#define   PWR_CMD3   0xC0

// DISPLAY ON, CURSOR ON, BLINK ON
#define   DL_CMD1   0x00
#define   DL_CMD2   0xF0

// CLEAR DISPLAY COMMAND     
#define CLR_DSP1 0x00
#define CLR_DSP2 0x10

// ENTRY MODE SET
#define ENT_MOD1 0x00
#define ENT_MOD2 0x60

#define LINE1 0x80
#define LINE2 0xC0

#define NULL 0x00

const char BANNER_1[] = {"Control: 100"};
const char BANNER_2[] = {"Value: 127"};

void LCD_Delay (unsigned long int d);
void LCD_IO_INIT (void);
void LCD_INIT (void);
void LCD_PutCmd (char);
void LCD_PutChar (char);
void LCD_PutString (const char *);

void main (void) {
   DDRA = 0xFF;
   PORTA = 0xFF;

   LCD_IO_INIT ();
   LCD_INIT ();

   /*
   LCD_PutCmd (LINE1);
   LCD_PutString (result);
   LCD_PutCmd (LINE2);
   LCD_PutString (BANNER_2);
   */
}

void LCD_Delay (unsigned long int d) {
    unsigned long int n;
    for (n = 0; n < d; n++);
}

void LCD_IO_INIT (void) {
    DDRA = 0xFF; // PORTA is the LCD DATA AND CONTROL LINES
    PORTA = 0x00;
    PORTA |= (1<<LCD_RS);
   PORTA |= (1<<LCD_E);
   LCD_Delay (500); // Wait for the up LCD to power up         
}

void LCD_INIT (void) {
   LCD_PutCmd (PWR_CMD1);
   LCD_PutCmd (PWR_CMD2);
   LCD_PutCmd (PWR_CMD3);

   _delay_us(40);
   
   LCD_PutCmd (DL_CMD1);
   LCD_PutCmd (DL_CMD2);

   _delay_us(40);
   
   LCD_PutCmd (CLR_DSP1);
   LCD_PutCmd (CLR_DSP2);

   _delay_ms(2);

   LCD_PutCmd (ENT_MOD1);
   LCD_PutCmd (ENT_MOD2);

    LCD_Delay (500); // Wait for the LCD to boot up   
}
 
void LCD_PutCmd (char c) {
  PORTA &= ~(1<<LCD_RS);
  LCD_Delay (5); // Wait for the proper setup time to respond to the RS control line
  LCD_PutChar(c);
  LCD_Delay (5); // Wait for the proper setup time to respond to the command being applied
  PORTA |= (1<<LCD_RS);
}


void LCD_PutChar (char c) {
    PORTA |= (1<<LCD_E);
    LCD_Delay (5); // Wait for the proper setup time to respond to the E pulse   
    PORTA = c;
    LCD_Delay (5); // Wait for the proper setup time to respond to the character being applied
    PORTA &= ~(1<<LCD_E);
}
 
void LCD_PutString (const char *p) {
    char n = NULL; // Pointer position counter.
    while (p[n] != NULL) // Keep sending data until the NULL character is found.
         LCD_PutChar(p[n++]);
}