3-draads LCD interface van Pros

#define COM           0
#define LCD_PORT      PORTB
#define LCD_DDR       DDRB
#define LCD_DATA_PIN  PB1
#define LCD_CLK_PIN   PB2
#define LCD_E_PIN     PB0
#define TXT           1

#define lcd_delay(x) _delay_loop_1(x)
#define lcd_command(x) char2LCD3(x, COM)
#define lcd_putchar(x) char2LCD3(x, TXT)

#define F_CPU 9600000UL

#include <avr/io.h>  
#include <util/delay.h>

int main(void) {
	DDRB |= 0x0F;
	//3 keer 0x30 sturen om lcd te starten
	_delay_ms(20);
	lcd_command(0x30);
	_delay_ms(5);
	lcd_command(0x30);
	_delay_us(160);
	lcd_command(0x30);
	_delay_us(160);

	lcd_command(0x38); //2line 8bit 5x7-dot
	lcd_command(0x08); //disp off
	lcd_command(0x01); //clear
	_delay_ms(2);
	lcd_command(0x06); //entry mode: increment, no shift
	lcd_command(0x0C); //disp on
	lcd_command(0x02); //cursor home
	lcd_command(0x0F); //cursor blink	

	_delay_ms(1);
	//Tekst tonen op LCD:
	lcd_putchar("a"); //"`"
	lcd_putchar("b"); //"b"
	lcd_putchar("c"); //"d"
	lcd_putchar("d"); //"f"
	lcd_putchar("e"); //"h"

	lcd_command(0xC0); //2e lijn
	lcd_putchar("A"); //"j"
	lcd_putchar("B"); //"l"
	lcd_putchar("C"); //"n"
	lcd_putchar("D"); //"p"
	lcd_putchar("E"); //"r"

	while(1){
		//knipperend ledje
		LCD_PORT |= 0x08;
		_delay_ms(100);
		LCD_PORT &= 0xF7;
		_delay_ms(100);
	}

}

//Functie van Pros:
void char2LCD3(unsigned char karakter, unsigned char RS)
{
    unsigned char cnt;

    for (cnt = 0; cnt < 8; cnt++) {
        if ((karakter & 0x80) == 0x80) {                        // een '1'
            LCD_PORT |= (1 << LCD_DATA_PIN);                    // LCD_DATA_PIN hoog
        } else {                                                // een '0'
            LCD_PORT &= ~(1 << LCD_DATA_PIN);                   // LCD_DATA_PIN laag
        }
        lcd_delay(5);
        LCD_PORT |= (1 << LCD_CLK_PIN);                         // Seriele klok hoog
        lcd_delay(5);
        LCD_PORT &= ~(1 << LCD_CLK_PIN);                        // Seriele klok terug laag
        karakter = karakter << 1;                               // Bits een plaatsje naar rechts schuiven
    }
    if (RS == TXT) {
        LCD_PORT |= (1 << LCD_DATA_PIN);                        // Tekst, RS moet hoog
    } else {
        LCD_PORT &= ~(1 << LCD_DATA_PIN);                       // Instructie, RS moet laag
    }
    lcd_delay(5);
    LCD_PORT |= (1 << LCD_E_PIN);                               // schuifregister -> par. uitgang
    lcd_delay(20);
    LCD_PORT &= ~(1 << LCD_E_PIN);                              // par. uitgang -> LCD-module

	//extra wachttijd:
	_delay_us(50);
}

	lcd_putchar("0");
	lcd_putchar("1");
	lcd_putchar("2");
	lcd_putchar("3");
	lcd_putchar("4");
	lcd_putchar("5");
	lcd_putchar("6");
	lcd_putchar("7");