GccApp1

#include <avr/io.h>
#include <avr/interrupt.h>
#define F_CPU 9600000UL
#include <util/delay.h>
#include <stdlib.h>

void abc(unsigned char a,unsigned char b,unsigned char c,unsigned char status);

unsigned char tonight=0;
volatile unsigned char pwm[3]={0,0,0};//здесь храним значения яркости светодиодов
unsigned char to[3]={0,255,0};//здесь храним цвет, к которому будем стремиться.

int main(void)
{
    //порты PB0-2 как выходы, выключены
    DDRB |= (1<<0|1<<1|1<<2);
    PORTB&= ~(1<<0|1<<1|1<<2);
    //Инициализация таймера
    TCCR0A = 0x00;
    TCCR0B = 0x01;//No Prescaling
    TIMSK0 = 1<<TOIE0;//Прерывание по переполнению
    sei();//Глобальное разрешение прерываний

    while(1){
        if (pwm[0]<to[0]) pwm[0]++;
        if (pwm[0]>to[0]) pwm[0]--;
        if (pwm[1]<to[1]) pwm[1]++;
        if (pwm[1]>to[1]) pwm[1]--;
        if (pwm[2]<to[2]) pwm[2]++;
        if (pwm[2]>to[2]) pwm[2]--;
        if(pwm[0]<=0&&pwm[1]<=0&&pwm[2]<=0) {//to red from black
            to[0]=0; //blue
            to[1]=255; //red
            to[2]=0; //green
        };
        if(pwm[0]<=0&&pwm[1]>=255&&pwm[2]<=0) {//to green+blue
            to[0]=255; //blue
            to[1]=255; //red
            to[2]=255; //green
        };

        if(pwm[0]>=255&&pwm[1]>=255&&pwm[2]>=255) {tonight=1;}

        if(pwm[0]>=255&&pwm[1]>=255&&pwm[2]>=255&&tonight==1) {//from green+blue
            to[0]=0; //blue
            to[1]=255; //red
            to[2]=0; //green
        };
        if(pwm[0]<=0&&pwm[1]>=255&&pwm[2]<=0&&tonight==1) {//from red to black
            to[0]=0; //blue
            to[1]=0; //red
            to[2]=0; //green
            };

        if(pwm[0]<=0&&pwm[1]<=0&&pwm[2]<=0) {tonight=0;}

        _delay_ms(50);
    }
}

ISR(TIM0_OVF_vect)
{
    static unsigned char e = 0;
    if( e == 255)
    {
        e=0;
        PORTB |= (1<<0)|(1<<1)|(1<<2);
    }
    abc(pwm[0],pwm[1],pwm[2],e);
    ++e;
}

void abc(unsigned char a,unsigned char b,unsigned char c,unsigned char status) {
    if((status==a)) PORTB&= ~(1<<0);
    if((status==b)) PORTB&= ~(1<<1);
    if((status==c)) PORTB&= ~(1<<2);
}