// mega88, 8 MHz
#include <avr/io.h>
#include <avr/interrupt.h>

#define setbit(port,bit)  ((port) |=  (1<<bit)) 
#define clrbit(port,bit)  ((port) &= ~(1<<bit)) 

#define port PORTB    //output pin = portb.1
#define outpin  1
#define ddr  DDRB  
#define SERVOCOUNT 8  //počet serv

//časy serv[us], poslední je synchro mezera
uint16_t servo[] = {1000,1500,2000,1000,
                    1500,2000,1000,1500,10000};

//------------------------------
ISR (TIMER1_OVF_vect) 
{ 
static uint8_t ind=0;
   setbit(port,outpin); // začátek pulsu
   ICR1 = servo[ind];   // nastavení času serva
   ind++;               // připrav index pro další servo
   if(ind > SERVOCOUNT) ind = 0;
}

//------------------------------
ISR (TIMER1_COMPA_vect) 
{ 
   clrbit(port,outpin); // konec pulsu
}

//==============================
int main (void) 
{ 
   // config timer1, mode=15, fast pwm, top=ICR1, presc=8
   TCCR1A = (1<<WGM11);
   TCCR1B = (1<<WGM12)|(1<<WGM13)|(1<<CS11);
   TIMSK1 = (1<<TOIE1)|(1<<OCIE1A); // enable interrupts
   
   setbit(ddr,outpin); // set as output
   OCR1A = 250;        // impuls = 250 us
   sei();

   for (;;) 
   { 
   } 
}//main