Testen ob ein Display kaputt ist

#define LCD_RST PB1

#define SPI_CS  PB2

#define LCD_DC  PB0

#include <avr/io.h>

#include <util/delay.h>

int main(void)

{

  DDRB = 0xff;

  PORTB = 0x00;

  PORTB &= ~(1<<LCD_RST);

  _delay_ms(5);

  PORTB |= (1<<LCD_RST);

  spi_init();

  lcd_out(0x21, 0);

  lcd_out(0xc0, 0);

  lcd_out(0x06, 0);

  lcd_out(0x13, 0);

  lcd_out(0x20, 0);

  lcd_clear();

  lcd_out(0x0c, 0);

}

void lcd_out(unsigned char data, unsigned char datatype)

{

  PORTB &= ~(1 << SPI_CS);

  if(datatype == 0)

  {

    PORTB &= ~(1 << LCD_DC);

  }

  else

  {

    PORTB |= (1 << LCD_DC);

  }

  SPDR = data;

  while((SPSR & 0x80) == 0);

  PORTB |= (1 << SPI_CS);

}

void lcd_clear()

{

  unsigned int i;

  lcd_out(0x0c, 0);

  lcd_out(0x80, 0);

  for (i=0; i<504; i++)

  lcd_out(0xff, 1);

}

//spi

void spi_init(void)

{

  SPCR = (1 << SPE) | (1 << MSTR) | (1 << SPR0);

}