#define F_CPU 1000000
#include <avr/io.h>
#include <util/delay.h>
#include <math.h>

#define OutputCompareRegister1 OCR1A
#define OutputCompareRegister2 OCR1B

#define PWMDDR DDRB

#define PWMpin1 PB1
#define PWMpin2 PB2

uint8_t sine8bit[];

void sineWave8bit()
{
    for (int i=0; i<256; i++)
    {
        sine8bit[i]=128+(127*sin(2.0*M_PI*i/256));
    }
}


void init16bitPWM() //this function works for ATMega8 but needs to be configured for other AVR uCs (configure the registers and the bits)
{
    PWMDDR |= 1<<PWMpin1;
    PWMDDR |= 1<<PWMpin2;


    TCCR1A |= 1<<WGM11 | 1<<COM1A1 | 1<<COM1B1;
    TCCR1B |= 1<<WGM12 | 1<<WGM13 | 1<<CS10;

    ICR1 = 255;

    OutputCompareRegister1 = 0;
    OutputCompareRegister2 = 0;
}

void changeDuty16bit(uint16_t duty, uint8_t channel)
{
    switch (channel)
    {
    case 1:
        OutputCompareRegister1=duty;
        break;
    case 2:
        OutputCompareRegister2=duty;
        break;
    }
}

int main(void)
{
    //Initialization
    init16bitPWM();
    sineWave8bit();

    //Variables
    int i;

    //Infinite loop
    while(1)
    {

        for (i=0;i<256;i++)
        {
            changeDuty16bit(sine8bit[i],1);
            _delay_us(5);
        }
    }
}