ADC i PWM kod

#include <avr/io.h>
#include "avr/interrupt.h"
unsigned char cnt=0;
void speedControl(unsigned int speed){
 float _dutyCycle;
 unsigned int dutyCycle;
 _dutyCycle=speed*(100.0/1024);
 //dutyCycle=20;
 dutyCycle=10+(int)_dutyCycle;
 if(cnt<dutyCycle) PORTD|=(1<<0);
 if(cnt>=dutyCycle)  PORTD&=~(1<<0);
 if(cnt>=100) cnt=0;
}
int main(void)
{  unsigned int adcResult;
 //PortD as output
 DDRD=0xFF;
 //PA0 or ADC0 as an analog input
 DDRA=0;
 //Set 1:8 pre-scaler
 TCCR0=0x02;
 //Clear overflow flag
 TIFR=0x01;
 //Enable Timer 0 interrupt
 TIMSK=0x01;
 //set global interrupt
 sei();
 //Turn on the ADC module
 ADCSRA|=(1<<ADEN);
 /*Select ADC7*/
 ADMUX|=0x07;
 while (1)
 {
  //Start the conversion
  ADCSRA|=(1<<ADSC);
  //Wait for the completion
  while((ADCSRA&(1<<ADSC))==1);   //Read the result
  adcResult=ADCL+(ADCH<<8);
  speedControl(adcResult);
 }
}
ISR(TIMER0_OVF_vect){
 //Load -5 to make 10 uS interrupt time
 TCNT0=-5;
 cnt+=1;
 TIFR=0x01;
}