/* LED_fading_01.c ATmega88 @ 8MHz */
#include <avr/io.h>
#include <util/delay.h>

int main(void)
{
    DDRB |= (1<<PB1); // OC1A = output
    ICR1 = 1000;        // Top Value = 1000
    OCR1A = 750;        // Compare Match bei 750

    // Mode 10: PWM, Phase Correct, Prescaler = 8, Clear OC1A on compare match
    TCCR1A = (1 << COM1A1) + (1 << WGM11);
    TCCR1B = (1 << WGM13) + (1 << CS11);

    while(1)
    {
        for (int i=0; i<=999; i++)       // OCR1A in 10ms Schritten bis 1000 inkrementieren
        {
            OCR1A = i;
            _delay_ms(10);
        }

        for (int i=1000; i>=1; i--)      // OCR1A in 10ms Schritten bis 0 dekrementieren
        {
            OCR1A = i;
            _delay_ms(10);
        }
    }
}