Simple .c LED-Fader

avr_fade_1.c

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

void sleep(uint8_t millisec)
{
        while(millisec)

        {
                _delay_ms(1);/* 1 ms delay */
                millisec--;
        }
}
int main()
{
        uint8_t pwm_to = 100;
        uint8_t pwm_is = 0;
        int8_t  pwm_fade_dir = -1;

        DDRC |=1<<PC2;  /* PC2 will now be the output pin */

        while(1)
        {
                for(uint16_t i=0;i<=16000;i++)
                        {
                        if(pwm_is==pwm_to)
                        {
                        PORTC |=(1<<PC2); /* PC2 HIGH */
                        }
                        pwm_is++;
                        if(pwm_is==100)
                        {
                                pwm_is=0;
                                PORTC &= ~(1<<PC2); /* PC2 LOW */
                        }

                }
                pwm_to+=pwm_fade_dir;
                if(pwm_to == 0 || pwm_to == 100)
                {
                        pwm_fade_dir*=-1;
                }
        }
        return 0;
}

/*
avr-g++ -g -Os -DF_CPU=16000000 -Wall -mcall-prologues -mmcu=atmega328p -fno-exceptions -o blink.obj blink.c

avr-objcopy -R .eeprom -O ihex blink.obj blink.hex

avrdude -P /dev/ttyUSB0 -b 19200 -c avr911 -p m328p -U flash:w:blink.hex

*/