LCD1602.h

#ifndef LCD1602_H
#define LCD1602_H

#include <delay.h>

//* Define port masks like (1 << 3) for GPIO_PIN_3.
#define RS     GPIO_PIN_5
#define RnW    GPIO_PIN_6
#define E      GPIO_PIN_7
#define DB7    GPIO_PIN_7
#define DB6    GPIO_PIN_6
#define DB5    GPIO_PIN_5
#define DB4    GPIO_PIN_0

//* Define port names like (GPIOA) for port A.
#define RS_PORT           GPIOC
#define RnW_PORT          GPIOC
#define E_PORT            GPIOC
#define DATA_PINS_PORT    GPIOD
#define DB7_PORT          GPIOD
#define DB6_PORT          GPIOD
#define DB5_PORT          GPIOD
#define DB4_PORT          GPIOD


#define DATA_PINS ((DB7)|(DB6)|(DB5)|(DB4))
// #define DATA_PINS ((DB7)|(DB6)|(DB5)|(DB4))
// #define DATA_PINS_OFFSET 4

#define PIN_LOW(X)    X##_PORT->ODR &= ~X
#define PIN_HIGH(X)   X##_PORT->ODR |=  X

#define PIN_OUTPUT(X) X##_PORT->DDR |=  X
#define PIN_INPUT(X)  X##_PORT->DDR &= ~X

#define PIN_READ(PIN_NAME) (PIN_NAME##_PORT->IDR & (PIN_NAME))

// #define LCD_CMD00_CLEAR
// #define LCD_CMD01_RETURN
// #define LCD_CMD02_ENTRY_MODESET
// #define LCD_CMD02_INC_nDEC
// #define LCD_CMD02_SHIFT_DISP_nCURSOR
// #define LCD_CMD03_DISP_ON_OFF_CTL
// #define LCD_CMD03_DISPLAY
// #define LCD_CMD03_CURSOR
// #define LCD_CMD03_BLINK
// #define LCD_CMD04_DISP_CURSOR_SHIFT
// #define LCD_CMD04_SCREEN_CURSOR
// #define LCD_CMD04_RIGHT_LEFT
// #define LCD_CMD05_FUNCT_SET
// #define LCD_CMD05_DATA_LENGTH
// #define LCD_CMD05_LINES_NUM
// #define LCD_CMD05_FONT
// #define LCD_CMD0
// #define LCD_CMD0
// #define LCD_CMD0
// #define LCD_CMD0
// #define LCD_CMD0
// #define LCD_CMD0
// #define LCD_CMD0
#define LCD_CMD  0
#define LCD_DATA 1


// Using project specific pin assigment
uint8_t read_data_pins()
{
//   return (((DATA_PINS_PORT->IDR & DATA_PINS) >> DATA_PINS_OFFSET) & 0x0F);
    uint8_t tmp;

    tmp = DATA_PINS_PORT->IDR & DATA_PINS;
    tmp = (tmp >> 4)|(tmp & 0x01);

    return tmp;
}

// Using project specific pin assigment
void write_data_pins(uint8_t data)
{
//   DATA_PINS_PORT->ODR = (DATA_PINS_PORT->ODR & ~DATA_PINS)|(data << DATA_PINS_OFFSET);
    uint8_t tmp;

    tmp = ((data << 4) & 0xE0)|(data & 0x01);

    __critical
    {
        DATA_PINS_PORT->ODR = (DATA_PINS_PORT->ODR & ~DATA_PINS)|(tmp);
    }
}

uint8_t read_nibble()
{
  uint8_t nibble;

  PIN_HIGH(E);
  __asm__("nop;\nnop;\n");
  nibble = read_data_pins();
  PIN_LOW(E);
  __asm__("nop;\nnop;\n");

  return nibble;
}

void write_nibble(uint8_t nibble)
{
  PIN_HIGH(E);
  write_data_pins(nibble & 0x0F);
  __asm__("nop;\nnop;\n");
  PIN_LOW(E);
  __asm__("nop;\nnop;\n");
}


uint8_t read_byte(uint8_t is_data)
{
  uint8_t byte;

  PIN_LOW(E);
  PIN_HIGH(RnW);
  if (is_data)
    {PIN_HIGH(RS);}
  else
    {PIN_LOW(RS);}
  PIN_INPUT(DATA_PINS);

  byte  = read_nibble() << 4;
  byte |= read_nibble();

  return byte;
}

void write_byte(uint8_t byte, uint8_t is_data)
{
  PIN_LOW(E);
  PIN_LOW(RnW);
  (is_data) ? (PIN_HIGH(RS)) : (PIN_LOW(RS));
  PIN_OUTPUT(DATA_PINS);

  write_nibble(byte >> 4);
  write_nibble(byte & 0x0F);
}

uint8_t lcd_is_busy()
{
//   _delay_ms(1); // Needed by ST7066 LCD controller
  return (read_byte(LCD_CMD) & 0x80) ? (0xFF) : (0x00);
}

void LCD1602_Init()
{
  PIN_LOW(RnW);
  PIN_OUTPUT(DATA_PINS);
  _delay_ms(40);
  write_nibble(0x03);
  _delay_ms(5);
  write_nibble(0x03);
  _delay_ms(5);
  write_nibble(0x03);
  _delay_ms(1);

  write_nibble(0x02);// LCD 4bit.
  _delay_ms(1);
  write_nibble(0x02);
  _delay_ms(1);
  write_nibble(0x08);
  _delay_ms(1);
  write_nibble(0x00);
  _delay_ms(1);
  write_nibble(0x08|0x04);
  _delay_ms(1);
  write_nibble(0x00);
  _delay_ms(1);
  write_nibble(0x01);
  _delay_ms(1);
  write_nibble(0x00);
  _delay_ms(1);
  write_nibble(0x06);
  _delay_ms(1);
//   while (lcd_is_busy());
//   write_byte(0x28, LCD_CMD); // LCD 4bit, 2 lines, 5x8 font
//   _delay_ms(1);
//   while (lcd_is_busy());
//   write_byte(0x08, LCD_CMD); // Display ON
//   _delay_ms(1);
//   while (lcd_is_busy());
//   write_byte(0x01, LCD_CMD); // Display Clear
//   _delay_ms(1);
//   while (lcd_is_busy());
//   write_byte(0b0110, LCD_CMD); // Entry Mode Set: increment addr, don't shift display
//   _delay_ms(1);
//   while (lcd_is_busy());
}

void LCD_SetXY(uint8_t x, uint8_t y)
{
  while (lcd_is_busy());
  write_byte(0b10000000|((0x40*y) + x), LCD_CMD);
}

void LCD_PrintString(char *str)
{
  while(*str != 0)
  {
    while(lcd_is_busy());
    write_byte(*str, LCD_DATA);
    str++;
  }
}

void LCD_Clear()
{
    LCD_SetXY(0,0);
    LCD_PrintString("                ");
    LCD_SetXY(0,1);
    LCD_PrintString("                ");
}


#endif